JOHANNES GUTENBERG-UNIVERSITÄT MAINZ - International ...

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JOHANNES GUTENBERG-UNIVERSITÄT MAINZ
Institut für Geowissenschaften
Prof. A. Kröner
A. Kröner • Universität Mainz • Geowissenschaften • 55099 Mainz •
Tel.: +49 6131/3922163
Fax: +49 6131/3924769
E-mail: kroener@mail.uni-mainz.de
Prof. J. Negendank 28 December 2006
Secretary-General, International Lithosphere Program
GeoForschungsZentrum Potsdam
Telegrafenberg
14473 POTSDAM
Germany
Re: Report 2006 for ILP Task Force 1 (Project ERAS - Earth Accretionary Systems)
Dear Jörg,
This is a progress report on activities of the ERAS Initiative for the calendar year 2006.
The ERAS proposal was originally formulated by P.A. Cawood (Perth, Australia), B.F. Windley
(Leicester, UK), A. Kröner (Mainz, Germany), T. Kusky (St. Louis, USA) and W. Mooney (Menlo
Park, USA) and submitted to ILP in 2003. It aims at multidisciplinary studies of accretionary
orogens and accretion processes though Earth history since these are much less well understood
than collisional orogens and are an important element of crustal growth and crustal recycling.
The Project was officially accepted by the ILP Board at its meeting during the Annual Meeting
of the European Geosciences Union (EGU) in Vienna in April 2005 and is now designated as ILP
Task Force 1 and is chaired by Peter Cawoood and myself.
In April 2006 Task Force 1 organized and sponsored two symposia at EGU in Vienna. The first
entitled "Accretionary orogens and crustal growth: facts, fiction, fantasy" chaired by P.A. Cawood,
P. Clift, A. Kröner, and the second "Composition, structure and evolution of the Caribbean
lithosphere" organized by A. Perez-Estaun, A. Garcia-Casco and Y. Rojas-Agramonte. Both
symposia were well attended and provided broad spatial and temporal coverage of the world’s
accretionary orogens, their role on generation of continental crust and the detailed character of their
assembly, deformation and metamorphism.
Also in April, Task Force 1 co-sponsored the joint meeting of the Geological Society of
America and Asociatíon Geológica Argentina, entitled “Backbone of the Americas - Patagonia to
Alaska” held in Mendoza, Argentina.
In June 2006 Task Force 1 co-sponsored a highly successful Penrose-Conference in Lander,
Wyoming, USA, on when plate tectonics began. This was organized by Kent Condie, Alfred

Kröner and Robert Stern and attended by 60 scientists from around the world. The main
issue was to discuss criteria and evidence concerning the beginning of plate tectonics in the
Precambrian, and a summary report was published in NATURE by one of the attending journalists
(Annexure 1). Accretionary orogens featured prominently at this meeting since Japanese geologists
claim to have recognized Japan-style ocean plate stratigraphy in early Archaean rocks at Isua,
Barberton and in the Pilbara greenstones of Western Australia. This issue will be the topic of a
forthcoming ERAS field workshop in 2007 (see below).
2
ERAS organized a whole-day symposium at the Australian Earth Sciences Convention in
Melbourne on July 6 entitled “Accretionary Orogens: their composition, structure and evolution”
and chaired by P.A. Cawood, W. Collins and G. Skilbeck. The symposium honoured the
contribution of Professor Evan Leitch who spent a life time unravelling the accretionary history of
the Palaeozoic New England Orogen in eastern Australia. Gordon Lister gave the keynote address
on “Contrasting styles in accretionary versus collisional orogens”. The symposium was attended by
over 100 scientists, and topics ranged from Palaeoproterozoic accretionary tectonics in central
Australia to Gondwana assembly and through to modern arc systems of the Western Pacific, but
with a focus on the Palaeozoic accretionary architecture of eastern Australia.
ERAS scientists Bor-ming Jahn and Alfred Kröner organized and sponsored a super-session on
"Composition and Evolution of the Asian Lithosphere" at the third meeting of the Asia-Oceania
Geoscience Society in Singapore in early July 2006. This super-session included 11 separate
sessions list below (for complete descriptions see Annexure 2):
1. Evolution of the Asian continental mantle lithosphere - constraints from xenolith studies
(Bill Griffin, Sue O'Reilly, and Kuo-Lung Wang)
2. Lithospheric and mantle dynamics (David Yuen and Huai Zhang)
3. Growth and evolution of the Asian continent (M. Zhai, S. Wilde, G. Zhao, M. Cho)
4. Orogenic processes in Asia: regimes of continental collision (S.L. Chung, Mike Searle)
5. Orogenic processes in Asia: regimes of continental accretion (Alfred Kröner)
6. Generation of granitoids in Asia and Australia (W. Collins, T. Nakajima, Fuyuan Wu)
7. Deep Structure and Tectonics of the Asian Lithosphere: The Geophysical Perspective
(Larry Brown, Dapeng Zhao, Bor-Shouh Huang, Wangping Chen)
8. Evolution of the SW Pacific and South China Sea (S.K. Hsu, R. Shinjo, T.Y. Lee)
9. Crustal deformation and neotectonics in Asia (Yue-Gau Chen, Jian-Cheng Lee, Kerry
Sieh, Yuichi Sugiyama)
10. Ore deposits and economic geology in Asia (Shunso ISHIHARA, Jingwen MAO)
11. Gem materials - from diamond to pearls (W. Hofmeister, Vu Xuan Quang)
A highlight of the year’s activities was an ERAS field workshop in Japan in September
consisting of a 1.5 day symposium and a 4 day field trip, organized by Gaku Kimura, Yukio Isozaki
and Shigenori Maruyama (see Annexure 3). The workshop enabled scientists from Precambrian and
Phanerozoic accretionary terranes from around the world to see the classic arc accretionary
sequences exposed in the subduction complex assemblages including the ocean floor stratigraphic
sequences preserved therein. The symposium was divided into a half day open session as part of the
Geological Ssociety of Japan Annual Meeting and a one day closed session limited to ERAS
participants. Talks focused on the spectacular onland and offshore accretionary complexes in Japan.

3
Task Force 1 also co-sponsored a 4-day Sino- German workshop in Beijing on the evolution
of Palaeozoic to Mesozoic orogenic belts in Central Asia. This was funded by the Sino-German
Centre for Research Promotion and organized by Wenjiao Xiao (Beijing) and Alfred Kröner
(Mainz) and attended by 30 Chinese, 12 German, two Australian one British, one French and one
Russia scientist. Emphasis of the discussion was on tectonics, petrology of UHP terranes,
geochronology and palaeomagnetism (Annexure 4). Qincheng Wang, the Chinese Member of the
ILP Bureau, attended this meeting, and suggested to establish a Regional Working Group for the
Central Asian Orogenic Belt under Task Force 1 and supported by the Regional Committee for
Asia in view of the increasing interest of scientists from China, Russia, Kazakhstan and Kyrgyzstan
in this region.
Alfred Kröner and Larry Brown initiated discussions on a major seismic-geologic traverse
across the Central Asian Orogenic Belt from the Siberian craton to the Sino-Korean craton (see
Annexure 4). This multi-disciplinary “Lithoprobe-style” project should be organized under the
umbrella of Task Force 1 and will require major funding from both China and Russia. Discussions
so far have been very encouraging, and a technical workshop will be held in Beijing in April 2007.
Plans for 2007 include a field workshop in the Pilbara region of western Australia. This region is
critical in evaluating the time of formation of the worlds earliest accretionary processes as well as
the initiation of plate tectonics. Controversy surrounds the region with some geologists favouring
an ocean floor setting involving generation of ocean lithosphere and its conveyor belt like motion to
a subduction zone, whereas others dispute this claim. Our aim is to have both groups present their
evidence at the critical outcrops along with a group of ERAS scientists to evaluate the evidence.
This region was selected by the GSA Penrose conference on the initiation of plate tectonics in June
2006 as a key issue to be resolved.
Task Force 1 will co-sponsor the Third Field Workshop of IGCP-Project 480 in Beijing, to be
held in August 2007 with a field trip to examine accretion tectonics and Palaeozoic ophiolites in
Inner Mongolia. ERAS will also co-sponsor the International Symposium on Precambrian
Chronology and Tectonic Evolution (ISPCTE), to be held in Beijing in August 2007, with four field
trips to Proterozoic and Archaean areas in China.
Also in 2007, a major book “Accretionary Orogens in Space and Time” edited by Peter A.
Cawood and Alfred Kröner, will be published as a Geological Society of London Special
Publication. The ILP logo will appear on the book. This will be a major output from Task Force 1.
March is set as the date for submission of papers, and it is hoped to have the revised and accepted
chapters submitted to the Geological Society for publishing by the second half of 2007. To date 29
chapters are planned with 13 providing an overview and discussion of general processes in
accretionary orogens and the remainder devoted to studies of specific orogens ranging in age from
early Archaean to Recent (a complete discretion of the books contents in given in Annexure 5) .

4
In 2008 Peter Cawood, Raimo Lahtinen and Yukio Isozaki will hold an ERAS symposium
at the Oslo International Geological Congress entitled “Accretionary Orogens: Character and
Processes”.
Yours sincerely,
Alfred Kröner, Co-Chairman
Annexures:
1. Report in NATURE on Penrose-Conference, June 2006
2. Description of Super-Session at AOGS Singapore, July 2006
3. ERAS field workshop in Japan, September 2006
4. Report on Sino-German Workshop on Central Asian tectonics in Beijing, December 2006
5. Proposal for a seismic-geologic transect across the Central Asian Orogenic Belt
6. Proposed Geological Society of London Special Publication on Accretionary Orogens.
Selected Publications
Buchan, C., Cawood, P.A., 2006. Linking accretionary orogenesis with supercontinent assembly.
Earth Sci. Rev., in press.
Cawood, P.A., Johnson, M.R.W. and Nemchin, A.A., 2006. Early Palaeozoic orogenesis along the
Indian margin of Gondwana: Tectonic response to Gondwana assembly. Earth Planet. Sci.
Lett., in press.
Cawood, P.A., Kröner, ,A, Pisarevsky, S., 2006. Precambrian plate tectonics – Criteria and
evidence. GSA Today, 16, No. 7, 4-11.
Isozaki, Y., 2006. "Overview: Evolution of the Japanese Islands" and "The Jurassic accretionary
complex in Inuyama". In: Fieldtrip guidebook for Int. Workshop ERAS (Earth Accretionary
Systems in space and time)-2006, 1-20, J1-J30.
Kawai, T., Windley, B.F., Terabayashi, M., Yamamoto, H., Maruyama, S., and Isozaki, Y., 2006.
Mineral isograd and zones of the Anglesey blueschist belt, UK: implications for the
metamorphic development of a Neoproterozoic subduction-accretion complex. J. Metam.
Geol., 24, 591-602.
Kröner, A., Windley, B.F., Badarch, G., Tomurtogoo, O., Hegner, E., Jahn, B.M., Gruschka, S.,
Khain, E.V., Demoux, A., Wingate, M.T.D., 2006. Accretionary growth and crust-formation
in the Central Asian Orogenic Belt and comparison with the Arabian-Nubian Shield. In: R.D.
Hatcher, Jr. (ed.), in: 4-D framework of the continental crust - Integrating crustal processes
through time. Memoir, Geol. Soc. America, in press.
Li, Songlin; Mooney, Walter, Fan, Jichang, 2006. Crustal structure of mainland China from deep
seismic sounding data. Tectonophysics, 420,
Liu, Mingjun; Mooney, Walter; Li, Songlin; Okaya, Nihal and Detweiler, Shane, 2006. Crustal
Structure of the northeastern margin of the Tibetan Plateau from the Songpan-Ganzi terrane
to the Ordos basin. Tectonophys, 420,

5
Osozawa, S., Tsolmon, G., Majigsuren, U., Sereenen, J., Jahn, B.M., 2006. Structural
evolution of the Bayanhongor region, west-central Mongolia. J. Asian Earth. Sci., in review.
Ota, A. and Isozaki, Y., 2006. Fusuline biotic turnover across the Guadalupian-Lopimgian
(Middle-Upper Permian) boundary in mid-oceanic carbonate buildups: Biostratigraphy of
accreted limestone in Japan. J. Asian Earth Sci. 26, 353-368.
Pisarevsky, S.A., Murphy, J.B., Cawood P.A.,, Collins, A.S., 2006. Late Neoproterozoic and early
Cambrian palaeogeography: models and problems. In Pankhurst, R. et al (eds.), Geol. Soc.
London, Spec. Publ., in press.
Rojas-Agramonte, Y., Kröner, A., Sukar, K., Mattinson, J., Somin, M. & Wingate, M.T.D., 2006.
Timing of Cretaceous island arc granitoid magmatism in Cuba as revealed by U-Pb SHRIMP
zircon dating: Significance for arc magmatism in the Caribbean. J. Geol., submitted.
Romanyuk, Tanya; Mooney, Walter; Detweiler, Shane, 2006. Two lithospheric profiles across
Southern California derived from gravity and seismic data. J. Geodynamics, submitted.
Trubitsyn, V., Kaban, M., Monney, W., Reigber, C., Schwintzer, P., 2006. Simulation of active
tectonic processes for a convecting mantle with moving continents. Geophys. J. Internat., 164, 3,
611-623.
Vijaya Rao, V., Sain, K., Reddy, P.R., Mooney, W.D., 2006. Crustal structure and tectonics of the
northern part of the Southern Granulite terrane, India, Earth Planet. Sci. Lett., 251, 90-103.
Wang, Tao, Hong, Da-wei, Jahn, B.M., Tong Y., Wang Yan-bin, Han Bao-fu, Wang Xiaoxia,
2006. Timing, petrogenesis and setting of Paleozoic synorogenic intrusions from the Altai
Mountains, Northwest China: implications for the tectonic evolution of an accretionary orogen.
J. Geol., 114, 735-751.
Wang, Tao, Jahn. B.M., Kovach, V.P., Tong, Y., Wilde, S.A., Hong, D.W., Wang, X.X., 2006.
Identification and petrogenesis of Mesozoic anorogenic granitic magmatism in the Altai
Paleozoic accretionary orogen (NW China) and its geological significance: U-Pb zircon age,
element and isotopic evidence (Lithos, in review.
Windley, B.F., Alexeiev, D., Xiao, W.J., Kröner, A., Badarch G., 2007. Tectonic models for
accretion of the Central Asian orogenic belt. J. Geol. Soc. London, 164, 31-47.
Zhao, J.M., Mooney, W.D., Zhang, X.K., Li, Z.C. Jin, Z.J., and Okaya, N., 2006, Crustal structure
across the Altyn Tagh Range at the northern margin of the Tibetan plateau and tectonic
implications. Earth Planet. Sci. Lett., 241, 804-814.

NEWS FEATURE NATURE|Vol 442|13 July 2006
On a sunny, breezy day in the Wind
River Mountains of Wyoming, a
group of geologists are peering
intently at a dark ridge of rock. Some
2.7 billion years ago, these rocks were alive with
volcanic fire. Today, they jut out of a mountainside
like the spiny tail of a sleeping dragon.
This rock, says Kevin Chamberlain, a geologist
from the University of Wyoming in
Laramie, could be a special kind — a lava
called a komatiite. Today, Earth’s interior is too
cool to produce this particular rock; 2.7 billion
years ago, the hot lava would have run like
water over the barren landscapes.
But as the other geologists chip off fresh layers
and scrutinize them through hand lenses,
murmurs of dissent start to grow. Most geologists
have never seen a komatiite; they are
found almost exclusively among rocks of the
Archaean era, which are more than 2.5 billion
years old and thus very rare. But these men
and women are experts in the truly old. And
on the Wyoming hillside few of them are convinced
that they are seeing the rock textures
typically found in komatiites.
The scene brings home the difficulties of trying
to study the early Earth — there aren’t many
old rocks to look at, and those that are around
are often so altered, chemically and physically,
as to be nearly indecipherable. But as if to recompense
those who study them, such ancient
rocks, particularly of Archaean age, offer geologists
great rewards. It is in the Archaean that the
first earthly ecosystems are found, with their
clues to life’s earliest days on the planet. And it is
in the Archaean that scientists can look for the
beginnings of plate tectonics.
Plate tectonics is the grand unified theory of
geology. Everything we see today, from the
abyssal plains of the oceans to the heights of
the Himalayas, is shaped by plate tectonics. As
far back as there has been complex life — and
perhaps even before — continents have come
together and moved apart in a dance that has
altered climates and geographies, opening up
new possibilities for life and sometimes closing
down old ones.
But it may not always have been so. Plate tectonics
is driven by Earth’s heat and constrained
by the physical and chemical properties of the
crust and mantle. The further back in time you
go, the more different these things are likely to
have been. It’s been argued that on the early
Earth, crustal plates, floating on a heat-softened
layer of material beneath, would have
simply been too thick and buoyant to get
dragged beneath each other as they are today.
And the greater temperature of the early Earth’s
innards would probably have made them move
128
The start of the world as we know it
Plate tectonics has created oceans and pushed up mountain ranges. But when did the process
that shapes the planet get going? Alexandra Witze joins the geologists debating the issue.
Ancient rocks, such as those in the Wind River Mountains, could help determine when plate tectonics began.
in very different patterns from those typical of
today’s tectonics.
On other Earth-like planets there’s no evidence
for today’s plate tectonics. Planets do
not have to work this way, and there was probably
a time when this one didn’t. “You don’t
just make a silicate planet and plate tectonics
starts,” says Robert Stern, a geologist at the
University of Texas, Dallas. “Something special
has to happen.”
Dynamic planet
The nature of that special something cuts to
the discipline’s philosophical heart. Since the
early nineteenth century, geology has been
ruled by the principle of uniformitarianism —
that the planet operates on unchanging laws,
and that the present can be used as a key to the
past. But how can that approach hold up when
a science from a world where plate tectonics
©2006
Nature Publishing Group
explains more or less everything is applied to a
world that may have lacked it? How can you
understand ancient rocks when you do not
know what processes put them there?
The geologists clustered around the possible
komatiites in the Wyoming hills had gathered
to discuss these questions. Their visit to
the mountain ridge had been organized as
part of a June conference held in Lander,
Wyoming. The specific aim of the meeting
was to try to fix a date for the onset of plate
tectonics: the earliest possibility is pretty
much straight after the planet formed, about
4.5 billion years ago; the latest is just
1 billion years ago.
To help them decide, the scientists brought
to the table data from an array of disciplines.
Geochemistry can help clarify the temperature
and pressure at which Archaean rocks formed.
Fragments of zircon crystals dated even earlier
A. WITZE

NATURE|Vol 442|13 July 2006 NEWS FEATURE
— to the Hadean eon, which stretches from
about 3.8 billion years ago to the planet’s birth
— can provide hints about what Earth’s surface
environment was like back then. Palaeomagnetic
studies can show how land masses
moved across latitudes. And structural geology
can identify features that, in today’s world
at least, seem to be indicative of plate tectonics.
But in all these approaches, as with the komatiites,
age makes the picture hard to discern.
Crashing continents
Scant and difficult-to-interpret evidence presents
one set of problems; slippery definitions
present another. Plate tectonics has lots of constituent
parts. It’s not just a theory of how
things move, but of how they are made and
from what. For example, explanations for different
sorts of volcanism in different settings
also explain why the mineral make-up of continental
crust and the crust beneath the oceans
is so different.
Working out which attributes are essential
to the theory, and which incidental, is not easy.
The 65 attendees at the Wyoming conference
came up with 18 different definitions of plate
tectonics. Three components, most agreed,
were key: there must be rigid plates at the surface
of the Earth; those plates must move apart
through ocean spreading, with new crust
being made where the sea floor pulls apart;
and the plates must on occasion dive beneath
each other at subduction zones (see graphic).
The problem is that Earth could display one
or even two of these properties without necessarily
having a system like that described by
modern plate tectonics (see ‘A world without
tectonics’). Take rigid plates. Palaeomagnetic
and other studies show that sections of Earth’s
crust moved relative to each other in the
Archaean, just as modern crustal plates do.
But ice floes on a polar sea move in the same
way, points out geophysicist Don Anderson of
the California Institute of Technology in
Pasadena — and those ice floes aren’t experiencing
plate tectonics.
Of the three, it seems subduction is closest
to being diagnostic of plate tectonics. Subduction
is the process by which one crustal plate
THE DRIVING FORCES OF PLATE TECTONICS
Volcano
Continental
plate
slips beneath another, to be recycled into the
mantle. Subduction requires rigid plates, and
as it involves the destruction of crust, new
crust must be created elsewhere, presumably
at oceanic spreading ridges (see graphic); otherwise,
continental crust would eventually disappear.
Some argue that this means plate
tectonics should date further back than the
earliest firm evidence for subduction.
A dramatic use of this argument is that
made by Stern. In a paper published last year,
he took an extreme position, proposing that
Earth has been free of plate tectonics for
almost four-fifths of its life, with the system we
“You don’t just make a silicate
planet and plate tectonics starts.
Something special has to happen.”
— Robert Stern
see today starting up only a billion years ago 1 .
He had two lines of argument. One was that
plate tectonics could not begin until Earth’s
crust was cool enough, and that barrier was
only passed about a billion years ago. The
other was that the only reliable evidence for
subduction on the early planet came from a
period more recent than that.
Stern points to the geological record of three
types of rock. Ophiolites are distinctive sections
of the ocean crust that gets mashed up,
often through subduction, on the edges of
continents. Stern argues that very few of these
rocks are more than a billion years old. Metamorphic
rocks called blueschists, produced by
squeezing the basalt from which oceanic crust
is made at high pressures but not very high
temperatures, are being made in today’s subduction
zones; none, Stern says, has been
found that is more than 800 million years old.
And rocks from ‘ultra-high-pressure terranes’
of the sort produced where one plate rides over
another are at most 630 million years old.
He also makes a more general point. A dramatic
shift, such as the introduction of plate
tectonics, must have had huge planetary consequences.
And between 780 million and 580
Subducting oceanic plate
Oceanic
spreading ridge
Mantle
upwelling
©2006
Nature Publishing Group
million years ago, Stern says, there was a series
of glaciations, some very extreme — giving rise
to the term ‘snowball Earth’. “It was a wild time
of change,” says Stern. “The biosphere was out
of control.” On the basis that dramatic effects
require dramatic causes, he argues that the
introduction of plate tectonics, and with it an
increase in planet-cooling volcanic eruptions,
might have precipitated the great glaciations.
An age gone by
After reading Stern’s arguments, Alfred
Kröner of the University of Mainz in Germany
fired off a rebuttal. He argues that there’s
plenty of evidence for plate tectonics stretching
back at least 3.1 billion years 2 — including
geochemical work, seismic images of the
‘sutures’ where colliding continents join and,
indeed, a few ancient ophiolites. “I believe we
can see these features all the way back” — possibly
all through the Archaean, says Kröner.
The exchange of papers led to the Wyoming
conference. “It was overdue,” says Kröner.
“Nobody ever talks to one another.” In
Wyoming, they did: palaeomagnetists clustered
around a white board with field geologists;
geophysicists sat down for a beer
with geochemists.
Some of the newly shared data favour an
early start for plate tectonics. Geoff Davies, a
modeller at Australian National University in
Canberra, presented work suggesting that one
of the biggest stumbling blocks to an early start
may have been removed. In the early 1990s,
computer models created by Davies and others
suggested that the crust on the early Earth
would have been too thick and buoyant to get
dragged down beneath another plate during
subduction. But new simulations, using more
sophisticated calculations, suggest that the
crust may have been thinner than once
thought 3 — as thin as 4 kilometres or less —
which would be thinner than today’s crust.
“Maybe plate tectonics on the early Earth was
viable after all,” says Davies.
In other cases, recent findings overturned
evidence for early plate tectonics. In 2001, a
team reported that an ophiolite from Dongwanzi,
China, was 2.5 billion years old — mak-
Passive continental
margin (no subduction)
129

NEWS FEATURE NATURE|Vol 442|13 July 2006
Clues to the past: zircon crystals (inset) in the Jack Hills of Western Australia have been used to argue for an early start to plate tectonics.
ing it by far the oldest such subduction remnant
yet discovered 4 . Now Guochun Zhao, of
the University of Hong Kong, has re-dated
those rocks, giving them an age of just 300 million
years.
Timothy Kusky of St Louis University in
Missouri, who led the original study, says that
Zhao took samples from a part of the rock
already known to be much younger than the
main part of the ophiolite. But several attendees
at the meeting said they found Zhao’s data
convincing. If true, it would pull the earliest
evidence for ophiolites at least half a billion
years towards the present, leaving the
Archaean an ophiolite-free zone.
The Chinese ophiolite isn’t the only evi-
130
dence that is getting fresh scrutiny. For a while
two independent groups have been quietly
warring over the significance of a pile of
ancient zircons from the Jack Hills region of
Western Australia. The zircons are crystals
that formed in the Hadean and later became
incorporated into younger rocks.
Last year in Science 5 , geochemist Mark Harrison
of the University of California, Los Angeles,
and colleagues used the Jack Hills zircons to
argue that continental crust was present 4.4 billion
to 4.5 billion years ago. The evidence
comes in the form of hafnium isotope ratios in
the zircon crystals, which preserve signals of
the lighter minerals typical of continental crust.
The data also suggest, Harrison argues, that
Time to talk: Earth scientists gathered at a meeting in Wyoming to present diverse data on the early Earth.
©2006
Nature Publishing Group
that crust was being recycled down into the
mantle by 4.4 billion years ago — perhaps
though a process similar to plate tectonics.
Simon Wilde of the Curtin University of
Technology in Perth, Australia, isn’t so sure.
“You have to be very careful with these rocks,”
he says. Measuring one spot on a crystal, as
opposed to another, can yield very different
hafnium values that lead to very different interpretations,
he says. Wilde argues that the zircons
should be interpreted more conservatively
— that the evidence points to there being some
continental crust, but not plate tectonics and its
associated recycling, by 4.4 billion years ago 6 .
Ground forces
Such differences of interpretation make the
problem of solving when plate tectonics began
extremely difficult. In many cases, data can be
interpreted in several completely different
ways — all of which may seem valid.
For instance, another Australian geologist
presented seemingly convincing evidence that
plate tectonics had begun by 3.3 billion years
ago in Western Australia, based on the very
different histories of two sections of an ancient
rock formation called the Pilbara. Hugh
Smithies of the Geological Survey of Western
Australia says that the eastern part of the Pilbara,
between 3.5 billion and 3.2 billion years
old, “shows no clear evidence for modern-style
plate tectonics”. It contains some geochemical
markers that suggest subduction, but they
could just as easily be explained by hot
upwellings of rock known as mantle plumes or
other non-tectonic phenomena.
In contrast, looking at the western part of the
Pilbara — which is 3.3 billion to 3.0 billion years
old — Smithies sees plenty of evidence for plate
tectonics. There are geochemical signatures that
cannot be explained by other factors, and the
M. HARRISON
A. J. VAN DER VELDEN

NATURE|Vol 442|13 July 2006 NEWS FEATURE
Slow work: geologists hunt for structural signatures in rocks that can only be explained by plate tectonics, to try to identify when the process started.
rocks show features that hint that plates had
interacted along their edges. Smithies thinks the
western Pilbara contains the remains of an
oceanic arc — the sort of line of islands, such as
the Aleutians of Alaska, that are characteristic
of some oceanic subduction zones 7 .
But then along came Julian Pearce of Cardiff
University in Wales, who argued that each of
the geochemical markers in the western Pilbara
can be explained by other phenomena,
A WORLD WITHOUT
TECTONICS
With so much uncertainty over Earth’s early
history, not many geologists are willing to
imagine entirely different ways in which the
world might have worked before plate
tectonics. One of the brave few is Jean
Bédard, a geologist at the Geological Survey
of Canada.
At a June conference held in Lander,
Wyoming, Bédard presented one of the few
fully worked out accounts of how a pre-platetectonic
Earth might have worked. In his
model, hot upwellings of rock known as
mantle plumes partly melt the crust above
them. This melting distills the crust, producing
material from which light, continental-style
crust is made.
The material left behind as the melt is
creamed off — denser than it was before the
distillation — then detaches itself from the
crust and sinks back into the mantle. There, it
would mix with more mantle material — and
the whole process would start all over again 9 .
Bédard himself admits that he has no idea if
his proposal is right. But it is, he says, a
detailed alternative theory to plate
tectonics, and one that can be tested
with further studies. A.W.
such as magmas with an unusual amount of
water in them, or crustal material from different
places getting mixed up. The various
researchers are hoping to settle the matter with
a field trip. An excursion is already planned for
next year, to re-examine the evidence for plate
tectonics in the western Pilbara.
Field trips don’t always resolve things. In the
Wind River Mountains, the meeting attendees
continued to argue about plate tectonics as
they hiked from outcrop to outcrop. But a
week of communing at the conference and
under the high mountain sun brought them
toward a consensus of sorts.
Meeting organizers polled the attendees
twice on when they thought plate tectonics
began. At the beginning of the meeting, guesses
were spread over more than 3 billion years of
Earth history. At the end, a closing ballot
showed that many had begun to push their
thinking further back into the past; a majority
of attendees voted for plate tectonics having
started between 3 billion and 4 billion years ago.
Kent Condie, one of the meeting organizers,
calls that a success. “We’ve got a majority
favouring a definition and approach,” says
Condie, of the New Mexico Institute of Mining
and Technology in Socorro, New Mexico.
“Sure, there will be a minority point of view.”
At the conference, that minority pretty
much constituted Stern. By the end of the
meeting, he remained the one person voting
for a start to plate tectonics at 1 billion years
ago. “It’s not a simple question,” he maintains.
And on that, at least, others agree.
Michael Brown, a geologist at the university
of Maryland in College Park, doesn’t endorse
Stern’s late start. But he does think that the
nature of plate tectonics changed around that
time. In a paper in press in Geology 8 , Brown
suggests that there have been two styles of
©2006
Nature Publishing Group
plate tectonics: the modern kind that we see
today, and an earlier version that lasted from
about 2.7 billion to 700 million years ago. Evidence
for the earlier style, he says, comes from
minerals that are typical of higher-temperature,
lower-pressure environments; these suggest
a hotter Earth where plates did not
subduct beneath each other to great depths
and pressures. Minerals characteristic of highpressure
environments typify the later style.
The properties of these minerals suggest to
him that true plate tectonics, in which one
plate subducts deeply beneath another, did not
begin until about 700 million years ago.
And there is a possible further complication.
Geophysicist Paul Silver, of the Carnegie
Institution of Washington, raised the notion
that plate tectonics may have started and
stopped several times during Earth’s history.
This is also an idea that Stern is comfortable
with — he uses it to explain the presence of a
small number of ophiolites about 2 billion
years ago.
An ‘intermittent approach’ would be a wonderful
way to reconcile things — but it takes
geology even further from the comforting
realm of uniformitarianism, into a world
where the most basic principles come and go
in fits and starts. ■
Alexandra Witze is Nature’s chief of
correspondents for America.
1. Stern, R. J. Geology 33, 557–560 (2005).
2. Cawood, P. A., Kröner A., Pisarevsky, S. GSA Today 16, 4–11
(2006).
3. Davies, G. F. Earth Planet. Sci. Lett. 243, 376–382 (2006).
4. Kusky, T. M., Li, J-H. & Tucker, R. D. Science 292, 1142–1145
(2001).
5. Harrison, T. M. et al. Science 310, 1947–1950 (2005).
6. Valley, J. W. et al Science 312, 1139a (2006).
7. Smithies, R. H. et al. Gondwana Res. (in the press).
8. Brown, M. Geology (in the press).
9. Bédard, J. Geochim. Cosmochim. Acta 70, 1188–1214
(2006).
131
A. POLAT

ERAS Report for 2006 - Annexure 2
Solid Earth (SE) Super-session on
AOGS-2006 (July 10-14, Singapore)
"Composition and Evolution of the Asian Lithosphere"
Bor-ming Jahn (Taipei) and Alfred Kröner (Mainz)
Prof. Bor-ming Jahn,
Institute of Earth Sciences, Academia Sinica
P.O. Box 1-55, Nankang
Taipei, 11529 Taiwan
e-mail: jahn@earth.sinica.edu.tw
Prof. Alfred Kröner
Institut fuer Geowissenschaften, Universität Mainz
55099 Mainz, Germany
e-mail: kroener@mail.uni-mainz.de
Component sessions and their descriptions:
1. Evolution of the Asian continental mantle lithosphere - constraints from xenolith
studies (Bill Griffin, Sue O'Reilly, and Kuo-Lung Wang)
The continents are underlain by roots of sub-continental lithospheric mantle (SCLM), which
vary in thickness, composition and thermal state depending on the age and tectonothermal
history of the overlying crust and its tectonic setting. Understanding the evolution of the
SCLM, and its causes, is essential to understanding the growth and stability of continents and
long-term mantle processes. Recent studies document a change from thick, cool and depleted
Archaean SCLM to thin, hot and fertile SCLM in eastern China. What mechanisms can cause
thinning and replacement of ancient SCLM, which is gravitationally stable? How does new
lithosphere form?
Professor Suzanne Y. O'Reilly
GEMOC Key Centre, Department of Earth and Planetary Sciences
Macquarie University
Sydney NSW 2109, Australia
E-mail: soreilly@els.mq.edu.au
Professor William L. Griffin
GEMOC Key Centre, Department of Earth and Planetary Sciences
Macquarie University
Sydney NSW 2109. Australia
E-mail: wgriffin@els.mq.edu.au
Dr. Kuo-Lung Wang
Institute of Earth Sciences, Academia Sinica
128, Sec. 2 Academia Road
Nankang, Taipei 115
Taiwan, R.O.C.
E-mail: kwang@earth.sinica.edu.tw

2. Lithospheric and mantle dynamics (David Yuen and Huai Zhang)
This session will focus on fundamental issues of heat and mass transfer in the Earth's mantle
and its nonlinear interaction with the crust and lithosphere. We welcome contributions from
many vantage points, especially from multiscale points of view, towards this goal. Topics
ranging from both laboratory experiments to numerical simulations are appropriate.
Constraints from other geochemical and geophysical observations, in particular seismology
and mineral physics, are particularly welcome. We encourage contributions from younger
scientists.
Prof. David A. Yuen
Dept. of Geology and Geophysics and Minnesota Supercomputer Institute,
University of Minnesota,
Minneapolis, MN 55455-0219, USA
e-mail: davey@krissy.geo.wmn.edu
Prof. Huai Zhang,
Laboratory of Computational Geodynamics,
Chinese Academy of Sciences, Beijing, China
e-mail: hzhang@gweas.ac.cn
2
3. Growth and evolution of the Asian continent (M. Zhai, S. Wilde, G. Zhao, M. Cho)
Asia is evolving into the next supercontinent, composed of diverse terranes; each with its own
unique story. Outstanding issues include the nature and distribution of the earliest crustal
components; the relative roles of mantle plumes versus subduction-related processes in the
Archean; the nature and timing of anorogenic magmatic and rifting events in the Proterozoic;
the evidence for, and timing of, continental collisions; crustal growth during the Phanerozoic;
evaluating geological correlations between various crustal components; and detailing the
consequences of mantle processes as they impinge on the evolving crust. We welcome
contributions on these and other related issues.
Mingguo Zhai,
Institute of Geology & Geophysics,
Chinese Academy of Sciences, PO Box 9825,
Beijing 100029, China
e-mail: mgzhai@mail.igcas.ac.cn
Simon Wilde,
Department of Applied Geology,
Curtin University of Technology, PO Box U1987,
Perth, 6845, Western Australia
e-mail: wildes@lithos.curtin.edu.au
Guochun Zhao,
Department of Earth Sciences,
The University of Hong Kong,
Pokfulam Road, Hong Kong
e-mail: gzhao@hkucc.hku.hk
Moonsup Cho,
School of Earth & Environmental Sciences,
Seoul National University,
Seoul, 151-747, South Korea

e-mail: moonsup@snu.ac.kr
3
4. Orogenic processes in Asia: regimes of continental collision (S.L. Chung, Mike Searle)
Collision between two continental plates would induce uplift of the crust and hence making
mountains of high elevation. However, due to the diverse lithologies and heterogeneous stress
fields, the resulting uplift cannot be identical in different parts of a collisional orogen. This
has been well demonstrated for the Tibetan plateau. The Himalayan-Tibetan orogen is the
most outstanding natural laboratory for studying the collisional orogeny and the influence of
its uplifted topography on the ocean water chemistry and climatic changes on Earth.
Continental collision also leads to subduction of apparently unsubductible continental crust.
This has tremendous implications for crustal recycling and for our understanding of
metamorphic processes in ultrahigh pressure conditions.
Prof. Sun-Lin Chung
Dept of Geological Sciences
National Taiwan University,
Taipei, Taiwan
e-mail: sunlin@ntu.edu.tw
Dr. M.P.Searle
Dept. Earth Sciences, Oxford University,
Parks Road., Oxford, OX1 3PR, UK
e-mail: Mike.Searle@earth.ox.ac.uk
5. Orogenic processes in Asia: regimes of continental accretion (Alfred Kröner)
Orogenic collages of Asia consist mostly of subduction-accretion complexes. They provide
an excellent possibility to reconstruct regimes of accretion in the Phanerozoic history of the
Earth and their role in the formation of the continental crust. The Pacific side of Asia where
modern rock and structural assemblages of almost all possible varieties reveal gradual
transitions to the assemblages of the geological past is the best laboratory for deciphering of
the regimes of accretion. Their examination and comparison with the assemblages of Inner
Asia may stop a simplistic approach, in which a search for explanations of inconsistency in
stratigraphic, magmatic, and structural history is substituted by recognition of mute terranes.
Prof. Alfred Kröner
Dept. of Geosciences, University of Mainz
55099 Mainz, Germany
e-mail: kroener@mail.uni-mainz.de
6. Generation of granitoids in Asia and Australia (W. Collins, T. Nakajima, Fuyuan Wu)
In contrast to the eastern pacific rim (North and South America), where granites generally
formed in narrow ((

e-mail: bill.collins@townsville.edu.au
Dr. Takashi Nakajima
Geological Survey of Japan
Institute of Geology and Geoinformation
AIST Central-7, 1-1-1 Higashi, Tsukuba 305-8567, Japan
e-mail. tngeoch.nakajima@aist.go.jp
Dr. Fuyuan WU
Institute of Geology and Geophysics
Chinese Academy of Sciences
P.O. Box 9825, Beijing 100029, China
e-mail: wufuyuan@mail.igcas.ac.cn
4
7. Deep Structure and Tectonics of the Asian Lithosphere: The Geophysical Perspective
(Larry Brown, Dapeng Zhao, Bor-Shouh Huang, Wangping Chen)
A new generation of active and passive geophysical imaging experiments are revealing key
details about the deep structure of the Asian lithosphere. These observations represent critical
tests for tectonic speculations on the role of such fundamental issues as deep crustal flow,
extensional exhumation, igneous underplating, mantle delamination, palaeoplate reconstruction
and lithospheric plate recycling. This session will review recent geophysical surveys of the Asian
lithosphere, with a focus on regional multi-disciplinary transects across key terranes.
Prof. Larry D. Brown,
Institute of the Study of Continents,
Cornell University, Ithaca, NY, USA
e-mail: brown@geology.cornell.edu
Prof. Dapeng Zhao
Geodynamics Research Center
Ehime University
Matsuyama 790-8577, Japan
e-mail: zhao@sci.ehime-u.ac.jp
Dr. Bor-Shouh Huang
Institute of Earth Sciences
Academia Sinica
Taipei, Taiwan 11529
e-mail: hwbs@earth.sinica.edu.tw
Prof. Wangping Chen
University of Illinois
Department of Geology
Urbana-Champagne, IL, USA
e-mail: wpchen@uiuc.edu
8. Evolution of the SW Pacific and South China Sea (S.K. Hsu, R. Shinjo, T.Y. Lee)
The SW Pacific and South China Sea region is characterized by the presence of trench-arcback-arc
systems. During recent years, new observations and insights about the SW Pacific
and South China Sea have been accumulated. However, the formation and evolution of this
region is still under debate. To understand the complex system and evolution of the SW
Pacific and South China Sea, integration of works including onshore and offshore geological,

5
geophysical and geochemical investigations is required. This session will serve as a venue for
reexamining the evolutionary history of the SW Pacific and South China Sea and, hopefully,
leads to new discussions for the plate interactions and marginal basins formation.
Prof. Shu-Kun Hsu
Institute of Geophysics, National Central University,
Chung-Li 32001, Taiwan
Email: hsu@oc.gep.ncu.edu.tw
Prof. Ryuichi Shinjo
Department of Physics and Earth Sciences, University of the Ryukyus
Senbaru-1, Nishihara,
Okinawa 903-0213, Japan
E-mail: rshinjo@sci.u-ryukyu.ac.jp
Prof. Tung-Yi Lee
Department of Earth Sciences, National Taiwan Normal University,
88, Sec. 4, Tingjou Rd., Wenshan Chiu,
Taipei,Taiwan
E-mail: t44001@cc.ntnu.edu.tw
9. Crustal deformation and neotectonics in Asia (Yue-Gau Chen, Jian-Cheng Lee, Kerry
Sieh, Yuichi Sugiyama)
Asia is undergoing various styles of crustal deformation in response to diverse tectonic
settings. Regardless of their distribution, inter- or intra-plate and coseismic or interseismic,
scientists have long been studying the processes of deformation. Recently, the earthquake
related neotectonics draw much attention due to the disasters occurred in the past decade. In
order to explore the mechanism and behavior of the active crustal deformation, a great
number of scientific projects have been launched for such purposes using either traditional
investigation or novel remote sensing methods. Based on the published materials, it is
obvious that some results are consistent and sensible, but others are still in debate. This
session is aimed to discuss a variety of problems related to neotectonics, paleoseismology,
tectonic geomorphology, seismology, and geodesy of Asia.
Prof. Yue-Gao Chen
Dept of Geological Sciences, National Taiwan University,
Taipei, Taiwan
e-mail: ygchen@ntu.edu.tw
Dr. Jian-Cheng Lee
Institute of Earth Sciences, Academia Sinica
Taipei, Taiwan 11529
e-mail: jclee@earth.sinica.edu.tw
Prof. Kerry Sieh
California Institute of Technology, Seismological Lab,
MS 252-21, Pasadena, CA 91125, USA
e-mail: sieh@gps.caltech.edu
Dr. Yuichi Sugiyama
e-mail: sugiyama-y@aist.go.jp

10. Ore deposits and economic geology in Asia (Shunso ISHIHARA, Jingwen MAO)
Recent fast economic growth in the Asian countries have yielded a strong demand on mineral
resources, particularly Cu, Mo, W, In, Fe, Mn, PGE, Au, potash salt, etc., which are indispensable
for keeping modern technological societies active in those countries. The economic
geologists in that region have been encouraged to study on metallogenic models and their
corresponding geodynamic and historic processes as well as new prospecting methods, and
apply the results to actual mineral exploration. AOGS-2006 will provide an opportunity for
academic and industrial colleagues to exchange what you have done and what you will do.
Please bring your up-to-date research results to this conference. You are cordially invited to
this session.
Dr. Shunso ISHIHARA
Geological Survey of Japan,
AIST Tsukuba Central 7, Tsukuba, 305-8567, Japan
e-mail: s-ishihara@aist.go.jp
Dr. Jingwen Mao
Institute of Mineral Resources,
CAGS, Beijing 100037, China
e-mail: jingwenmao@263.net
6
11. Gem materials - from diamond to pearls (W. Hofmeister, Vu Xuan Quang)
Prominent deposits of gem materials of highest economic values are situated in Asia and
Australia. Diamonds from Australia, ruby from Thailand, Vietnam, and Myanmar, zircon and
sapphire from Sri Lanka, tourmaline and topaz from the Himalayan neighborhood, are highend
geo-materials. There is an increasing demand of them worldwide. Study of gem materials
is also essential for understanding of archaeological artifacts. Besides, bio-mineralogy is an
exciting new field of research. Pearl and ivory production is important in the Asian-
Australian region. We invite interested scientists to discuss the geology, market and nondestructive
analytical methods for gem materials, and advance of research on the connection
of inorganic and organic worlds.
Prof. Wolfgang Hofmeister
Institute of Geosciences
Johannes Gutenberg-University
D-55099 Mainz, Germany
e-mail: hofmeister@uni-mainz.de
Prof. Vu Xuan Quang,
Institute of Materials Science,
Vietnam Academy of Science and Technology,
Hanoi, Vietnam
e-mail: Quangvx@hn.vnn.vn

ERAS Report for 2006 - Annexure 2
ERAS
International Workshop on
Accretionary Orogens and Continental Growth
from the perspective of global mass circulation
(Circular – 3 July 2006)
Time: Sept 19 to 22, 2006
Place: Kochi Univ. Convention Center, Kochi (conference
meeting) and central Shikoku and Inuyama (field excursion)
Conveners :
Kimura Gaku, Dept. Earth and Planet. Sci. The Univeristy of Tokyo
Isozaki Yukio, Dept. Integrated Science, The University of Tokyo
Santosh M. Dept. Environmental Science, Kochi University
Sponsor: JSPS (Japan Society of Promoting Sciences)
Initiation and Aims of the workshop:
(A) Accretionary orogens are major sites of continental growth and important miner-
alization. They have been active throughout Earth history, and the modern
circum-Pacific orogenic belts are the most typical of them. This workshop is
aimed to discuss the processes for the initiation and development of accretionary
orogens, and to better understand the processes responsible for the global mass
circulation, cratonization and incorporation of accretionary orogens into
continental nuclei.
(B) The Japanese islands represent an excellent example of Phanerozoic accretionary
orogeny and continental growth. The proposed field excursion will allow the
participants to examine the geological evolution of East Asia.
(C) An international project “ERAS (EaRth Accretionary Systems in space and
time)” has been submitted to the International Lithosphere Program (ILP) for
approval. The ILP is an important program of the IUGS and IUGG (International
Unions of Geological Sciences and Geophysical Sciences of ISU). This workshop
will have an important publicity campaign for the project itself as well as for the

2
promotion of scientific activity of Japan.
(D) All invited speakers are heavy-weights in this research domain. Their
participation and the timing of the workshop (to be held in the same place and the
same time as the annual meeting of the Geological Society of Japan )will
certainly attract a large group of audience.
(E) We anticipate about 100 attendants at this meeting (but not the field excursion,
which is limited to about 30 participants). Besides the local participants, the
invited attendants come from Australia, UK, France, Germany, Canada, Korea.
We expect that our young researchers will greatly benefit from the highly
animated discussions provided by the international leading experts during the
meeting. We will also give ample opportunity for our young scientists to
exchange their ideas about on-going or pertinent research with the experts.
Status of the workshop preparation (as of 3 July 2006):
(A) The workshop comprises two parts: a one-and-a-half-day conference in the
University Conference Center at Kochi, followed by a 2-day field excursion in
central Shikoku and Inuyama area, central main island.
(B) A full-day conference (May 19) will be allocated to invited talks on the type
localities of world’s accretionary orogens. Different approaches (field-based,
structural, geochemical, isotopic, geophysical, etc.) will be presented to address
the orogenic processes and crustal growth. Differences between accretionary and
collisional orogens will be underlined.
(C) A half-day conference (May 20 morning) will be used to present the current
models and interpretations on the geological evolution of the Mesozoic East Asia,
as well as a brief introduction on the geology of the Japanese islands. This
should form a good preparatory overview for the following 2-day field
excursion.
Provisional schedule (Sept. 18 to 22, 2006)
Sept. 18 Monday – arrival of participants. All participants will be transported and
lodged in the Hotel. Registration of the participants, Ice breaker
Sept. 19 Tuesday – first day of the workshop
9h00 to 12h00 – morning talks on accretionary orogens
12h00 to 1300 – lunch
13h00 to 16h30 –afternoon talks on accretionary orogens
16h30 to 17h00-brief introduction of field excursion

Reception party of Japanese style cuisine.
Sept. 20 Wednesday – second day of the workshop.
3
Morning – Visit Yokonami peninsula to observe the Cretaceous Shimanto
accretionary complex, then travel to the Oboke gorge
Afternoon - Observe Cretaceous high-P/T Sanbagawa metamorphic rocks.
Stay in Hotel
Sept. 21 Thursday – third day of the workshop
Morning – visit ultramafic rocks in the high-P/T unit, and return to Kochi
airport.
Afternoon – take a flight from Kochi to Komaki (north of Nagoya, central main
island) and stay in the Inuyama International Youth Hostel with a good hot spa.
Sept. 22 Friday – fourth day of the workshop
Morning + early afternoon - observe the Jurassic accretionary complex of the
Mino-Tanba belt. End of the workshop
To Nagoya, Osaka, or Tokyo airport.
(To Tokyo ca. 3 hours; to Osaka 2 hours)
Please check Visa matter for participants with your travel agencies.
Y-class international travel into and out from Japan, domestic
transportation and accommodation (from 18 to 21: four nights and
foods) fees for the workshop invitees are covered by the workshop.
Accommodations for earlier arrival and later departure beyond the
workshops are not covered by the workshop.
Please contact with gaku@eps.s.u-tokyo.ac.jp for paper works of
payment documents of invitees and any questions.
List of invited speakers from foreign countries (Tentative):
Borming Jahn – Taiwan National University, Taiwan
Kröner, Alfred – professor, University of Mainz, Germany
Windley, Brian F. – professor, University of Leicester, United Kingdom
Cawood, Peter – professor, The University of Western Australia, Australia
Laurent Jolivert – professor, University Pierre et Marie Curie, France
Peter Clift – professor, University of Aberdeen, UK
Hugh Smithies – Geological Survey of W. Australia
John A. Pericival – Geological Survey of Canada, Ottawa
Moonsap Cho – Seoul National University

List of domestic speakers (Tentative):
4
Tatsumi, Yoshiyuki – professor, Japan Marine Science and Technology Center, Japan
Maruyama, Shigenori – professor, Tokyo Institute of Technology, Japan
Tsuyoshi Komiya – assistant professor, TIT, Japan
Dapeng Zhao – professor, Ehime University, Matusyama, Japan
Hikaru Iwamori – associate professor, University of Tokyo, Japan
Isozaki, Yukio – professor, University of Tokyo, Japan
Kimura, Gaku – professor, University of Tokyo, Japan
Field excursion leaders: Masaru Terabayashi, Kagawa University
Yoshitaka Hashimoto, Kochi University

ERAS Report for 2006 – Annexure 4
Sino-German Workshop on “Geodynamic Evolution of Central Asia in the Palaeozoic
and Mesozoic”, Beijing, China, December 4-8, 2006
The Sino-German Centre for Research Promotion (Chinesisch-Deutsches Zentrum für
Wissenschaftsförderung), in Beijing, China, funded a 5-day thematic workshop on
“Geodynamic Evolution of Central Asia in the Palaeozoic and Mesozoic” which was attended
by more than 50 participants representing eight countries (Germany, UK, France, Russia,
Australia, Italy, Cuba, and China). The workshop was co-sponsored jointly by Task Force I
(Earth Accretionary Systems) of the International Lithosphere Program (ILP), IGCP Project
480, and the State Key Laboratory of Lithospheric Evolution, Institute of Geology and
Geophysics, Chinese Academy of Sciences (CAS). It was superbly organized by a term from
the State Key Laboratory of Lithospheric Evolution, and Prof. Wenjiao Xiao, Head of this
Laboratory, and Prof. Alfred Kröner of Mainz University, Germany, were the executive chairs
of the workshop.
The meeting was conducted in the Conference Hall of the Sino-German Center for
Research Promotion with 4 days of oral presentations, followed by visits of the international
guests to laboratories of the CAS, the Chinese Academy of Geological Sciences (CAGS), and
China University of Geosciences.
During the conference, 44 presentations were given orally, listed in an abstract volume,
each followed by a long and heated discussion. The oral presentations were subdivided into
two major sessions: (1) Evolution of the Qinling-Kunlun, Dabie-Sulu and Pamir Ranges; and
(2) Evolution of the Central Asian Orogenic Belt. There were 15 talks in the first session and
29 in the second session. These sessions covered a variety of topics ranging from the formation
of the Chinese continent to specific mountain belts in Eastern and Central Asia, and emphasis
was on tectonics, metamorphic petrology, geochemistry and geochronology. In the final part of
the meeting, scientists from CAS, CAGS, China and Germany gave presentations of new
research initiatives arising from the workshop and discussion, e.g. a proposed
seismic-geologic traverse across the CAOB. There were also round-table discussions in small
working groups on future research projects.
Overall the workshop was of highly successful, and social events included an icebreaker
welcoming party and splendid and opulent dinner parties in a well-known Chinese restaurant.
All participants appreciated the scientific merit of the workshop and the chance to meet new
colleagues and research partners. The foreign participants were particularly impressed by the
high quality of analytical data presented by the Chinese researchers, and everybody agreed that
the geology of Central and Eastern Asia plays a unique role in understanding processes of crust
formation and continental evolution, since the area contains the largest Neoproterozoic to
Mesozoic accretionary terrains on our planet. The participation of Reinhard Rutz, Director of
Sino-German Center for Research Promotion, Zhenyu Yang, editor-in-chief of Episodes,
Mingguo Zhai, Deputy Director of the Institute of Geology and Geophysics (CAS), and

2
Qingchen Wang, Steering Committee of the International Lithospheric Program (ILP)
enlightened the discussions and stimulated further cooperation between individual scientists
and groups from various countries. All participants are looking forward to future collaboration,
and individual research projects are now in the process of being formulated.
We thank the Sino-German Centre for generous funding and hope that this workshop will
result in new research initiatives and new friendships.
Wenjiao Xiao
State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese
Academy of Sciences, China.
E-mail: wj-xiao@mail.igcas.ac.cn
Alfred Kröner
Institut für Geowissenschaften, Universität Mainz, Becherweg 21, 55099 Mainz, Germany
E-mail: kroener@mail.uni-mainz.der

ERAS Report for 2006 – Annexure 4
Proposal for a seismic/geological traverse across the Central Asian Orogenic
Belt from the Siberian craton to the North China craton
Compiled by L. Brown, W.L. Griffin, B.-M. Jahn, A. Kröner, B.F. Windley, and W. Xiao
The Central Asian Orogenic Belt (CAOB, Fig. 1) is one of the largest and least understood
orogenic systems on Earth. It constitutes an orogenic collage of island arcs, microcontinents,
accretionary wedges and ophiolitic mélange zones that evolved over a period of more than 700
million years (Ma) from about 1000 to ~250 Ma (Kröner et al., 2006; Windley et al., 2006). The
belt is considered to represent a major site of continental growth in the Neoproterozoic and
Palaeozoic (Sengör et al., 1993; Jahn, 2004) and contains important world-class metal deposits, two
of which have recently been discovered in southern Mongolia (Perello et al., 2001). The evolution
of this extremely large and long-lived accretionary orogen has been the subject of considerable
controversy for more than a decade since Sengör et al. (1993) proposed an innovative but highly
speculative model, deriving the entire orogen from one single, giant intra-oceanic island arc from
the early Cambrian (~540 Ma) Ma to the Permian (~260 Ma). The alternative, and more widely
accepted, interpretation explains the CAOB in terms of southwest Pacific-style accretion of arcs and
microcontinents and final collision between the Siberian and North China cratons (e.g. Ruzhentsev
and Mossakovskiy, 1996; Badarch et al., 2002; Dobretsov et al., 2003; Xiao et al., 2003, Kröner et
al., 2006; Windley et al, 2006, and references cited in all of the above).

2
Fig. 1. Central Asian Orogenic Belt (CAOB) sandwiched between Siberian craton on the north and
Tarim and Sino-Korean cratons in the south. Proposed seismic line extends from Lake Baikal to Inner
Mongolia. Also shown are two major sutures in the CAOB.
Although much new information has become available since the Sengör et al. (1993) synthesis
was published, particularly in the fields of geochronology, isotope and trace element geochemistry,
and sedimentology, there is still a lack of detailed structural work, particularly concerning the
mechanism of arc accretion, the nature and evolution of accretionary prisms and ophiolite mélange
zones, and the relationships and tectonic position, size and origin of microcontinents sandwiched
between the arc complexes. There is also controversy on subduction polarities, the nature, age and
origin of ophiolite complexes, and the origin of unusually large volumes of felsic magmatic rocks.
Seismic profiles extending from the Siberian craton into the CAOB (Zorin et al., 1993) and
across the Chinese Altai and Junggar belts (Wang et al., 2003) do not provide the kind of detailed
information on crustal structure that are exemplied by LITHOPROBE profiles in the Canadian
shield (e.g., Cook and Erdmer, 2005; Clowes and Li, 2005). Although modern attempts to use
passive techniques to delineate lithospheric structure are suggestive (e.g. Figure 2), they still lack
the resolution and credibility of contemporary active/passive imaging. Recent wide angle controlled
source surveys have improved our image of gross crustal structure in the vicinity of Lake Baikal
(e.g. Thybo et al., 2006), but near vertical deep reflection profiling is still lacking. We suggest that a
new seismic profile across the width of the CAOB, using modern techniques such as broadband,
reflection and refraction methods, in combination with a well defined structural/geochronological
/geochemical traverse, would provide much needed information to fully understand the evolution of
this belt. Seismic data would also help to resolve some of the many ambiguities such as size and
extent of microcontinental blocks, subduction polarities, generation of granitoids and the structure
of the subcrustal mantle beneath the CAOB.
Major problems to be solved: The proposed traverse would cross the following trans-CAOB
sutures (see Fig. 1), and it would be useful to establish whether they penetrate the entire crust and
extend into the upper mantle and, in view of current differences in interpretation, to determine their
polarities:
a. The Mongol-Okhotsk suture in central-eastern Mongolia that formed in the early Mesozoic.
Was subduction only to the north (Zorin, 1999), or to both north and south (Tomurtogoo et al.,
2005)?
b. The Main Mongolian Lineament that probably formed a plate boundary in the late Ordovician
between already-accreted terranes to the north and open ocean to the south (Badarch et al.,
2002; Kröner et al., 2006). The ocean was consumed by subduction to the north.

3
c. The end-Permian Solonker suture in Inner Mongolia that represents the closure of the Palaeo-
Asian Ocean and termination of the CAOB. Was subduction only to the south (Zhang et al.,
2003) or to both north and south (Xiao et al., 2003)?
Both the Mongol-Okhotsk and Solonker orogens have been described as of Himalayan-scale,
with potential massive crustal thickening caused by thrusting and/or magma additions, followed by
extensional collapse and formation of metamorphic core complexes (Zorin, 1999; Tomurtogoo et
al., 2005 ; Xiao et al., 2003). Seismic profiles could define the thrust structure (thin- or thickskinned)
and extensional detachments.
One of the major problems in understanding the tectonic development of Mongolia is: what lies
below the huge Hangay-Hentei basin – a Precambrian gneissic microcontinent or mafic arc-type
rocks? This concerns the highly controversial existence of a major Mongolian orocline that
dominates the structure of the northeastern CAOB (Sengör et al., 1993; Yakubchuk, 2002).
The most appropriate route for the geophysical traverse would follow the main asphalt road from
the Russian-Mongolian border at Sukhbaatar to Ulaanbaatar and then follow the road that parallels
the railway line to the Chinese border at Erenhot, and south from there to Inner Mongolia. This
straight-line road traverse would cross all the main sutures and orogens mentioned above.
Why use seismology? Most international seismic profiling projects such as COCORP and BIRPS
have studied collisional orogenic belts such as the Appalachians, Caledonides and Himalayas-Tibet.
This proposed geophysical profile from Lake Baikal to Inner Mongolia will be the first to cross a
major, wide accretionary orogenic belt that formed by processes similar to those that have created
the Japanese Islands and are presently active in the SW Pacific. Accordingly, it will provide
important new information on the fundamental structure of the continental crust.
Although all geophysical methodologies have important contributions to make in detailing
lithospheric structure, only seismology can provide the resolution of structure needed to correlate
surface geological features to depth with any confidence. Modern lithospheric seismic surveys
stress the combined acquisition and processing of near-vertical reflection recording of controlled
sources for structural detail, wide-angle recording of similar sources for delineation of bulk velocity
variations as a proxy for lithology, and passive seismic recording of teleseismic events to obtain
gross structure variations of major geologic interfaces such as the Moho and the base of the
lithosphere. Thus, seismic profiling is most often the core for any lithospheric survey

4
Fig. 2. Crustal structure (bottom) deduced from velocity variations (top) computed from across
from receiver function analysis of passive seismic data. From Zorin et al. (2002). Although this
interpretation is highly speculative, it is indicative of the kinds of lithospheric complexity that need
to be resolved by more detailed geophysical work in the future.
Geophysical techniques to be used: In addition to the primary seismic surveys described above,
magnetotelluric profiling coupled with gravity and magnetic data can provide key constraints on
structural geometry and lithology at depth. All of these geophysical techniques, to be effective,
require careful correlation to surface exposures. Thus they must be matched to petrologic,
geochemical and geochronologic studies of surface geology along the proposed profile route. In
addition, xenoliths from both crustal and mantle sources can provide unique information to help
constrain interpretation of the geophysical results for the lithosphere at depth.

5
Combination of geophysics with geological traverse: We suggest that the geophysical traverse is
combined with field-based geological, petrological, geochemical asnd geochronological studies in a
broad corridor along the proposed seismic line. This work should concentrate on structural studies
to link seismic reflectors at depth to surface structures, with particular emphasis on defining terrane
boundaries and understanding arc accretion and ophiolite emplacement. Petrological/geochemicalisotopic
studies will help to reconstruct geodynamic environments, and geochronology will
determine the ages of major magmatic, metamorphic and deformational events.
Xenolith studies: The dynamic evolution of the CAOB during and after its assembly will be
reflected in the relationships between the upper crust, the lower crust and the underlying
lithospheric mantle. For example, delamination of oceanic/arc lithosphere may have allowed
upwelling of the asthenospheric mantle, providing the heat necessary for the widespread felsic
magatism that followed the accretion of the CAOB (Jahn, 2004; Kröner et al., 2006; Zheng et al.,
2006). The traverse crosses a region with abundant Cenozoic basaltic rocks that carry xenoliths of
the deep crust and upper mantle; key areas include the Baikal rift zone (Litasov and Taniguchi,
2002) northern and central Mongolia ((Ionov et al. 1998), and the Dariganga lava plateau in
southern Mongolia/northern China ((Ionov et al., 1999). Lower-crust and upper-mantle xenolith
suites from localities near the traverse can be used to calibrate the seismic data in terms of rock
types and temperatures at depth. Isotopic data on lower-crustal xenoliths can define the timing and
nature of underplating events that contributed to crustal growth. Whole-rock and in-situ Re-Os
analysis (eg Griffin et al., 2004, and references therein) of ultramafic xenoliths can provide
constraints on the timing of mantle events, and to identify tectonic units (eg, microcontinents) that
may have carried ancient lithospheric mantle with them into the tectonic collage.
Isotopic studies: Radiogenic (Nd-Sr) and stable isotope (O) studies have significantly contributed
to identification of mantle-derived juvenile crust and to estimation of the proportion of juvenile to
recycled ancient crust (e.g., Jahn, 2004; Wickham et al., 1996). The CAOB is probably the most
exemplary of accretionary orogens and is considered to represent the most important site of
continental growth in the Phanerozoic (Sengör et al., 1993; Jahn, 2004), but the tectonic evolution
of this belt has been the subject of considerable debate in the last decade. Like in Japan, the CAOB
comprises magmatic arcs, ophiolites, accretionary complexes, and microcontinental blocks.
Accretionary complexes are not necessarily composed largely of juvenile material, as shown in the
case of the Japanese Islands. The characterization of any crustal segments in the CAOB must be
approached by field work and isotope/geochemical study. Since batholithic granitoids (e.g., in

6
Transbaikalia) represent melts derived by large-scale melting of the middle to lower crust, their
isotopic compositions are the best to represent the bulk of individual crustal segments. In any case,
zircon geochronology with Hf isotope measurements and Nd-Sr isotope studies will be carried out
in concert with geophysical and field investigations.
Schedule of Activities: We propose the following timescale to pursue the objectives outlined
above:
(1) An initial workshop for interested scientists to be held in conjunction with the IGCP-480
meeting in Beijing in August 2007. Possibly also a technical workshop on processing of seismic
data in Novosibirsk sometime in 2007.
(2) Development of a core proposal to be used by participants in fund raising in late 2007,
early 2008.
(3) Initial geophysical surveys in the Fall of 2008.
For more information, contact Alfred Kröner at kroener@mail.uni-mainz.de or Larry Brown at
ldb7@cornell.edu.
References cited
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implications for the Phanerozoic crustal growth of Central Asia. J. Asian Earth Sci., 21, 87-110.
Clowes, R.M. and Li, C (comp.), 2005. Lithoprobe celebratory conference, oral and poster
presentations. Lithoprobe Secretariat, Univ. British Columbia, Vancouver, Canada, Epublication
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Clowes, R.M., Calvert, A.J., Eaton, D.W., Hajnal, Z., Hall, J. & Ross, G.M. 1996. LITHOPROBE
reflection studies of Archean and Proterozoic crust in Canada. Tectonophysics, 264, 65-88.
Cook, F.A. and Erdmer, P. (eds.), 2005. The Lithoprobe Slave-Northern Cordillera lithospheric
evolution (SNORCLE) transect. Can J. Earth Sci., 42, 869-1311.
Dobretsov, N.L., Buslov, M.M. & Vernikovsky, V.A. 2003. Neoproterozoic to Early Ordovician
evolution of the Paleo-Asian ocean: implications to the break-up of Rodinia. Gondwana Res., 6,
143-159.
Griffin, W.L., Graham, S., O’Reilly, S.Y. and Pearson, N.J. 2004. Lithosphere evolution beneath
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Ionov, D.A., O’Reilly, S.Y. & Griffin, W.L. 1998. A geotherm and lithosphere section for Central
Mongolia (Tarat region). In: Flowers, M.F.J. et al. Mantle Dynamics and Plate Interactions in
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Ionov, D.A., Griffin, W.L. O’Reilly, S.Y. 1999. Off-cratonic garnet and spinel peridotite xenoliths
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Jahn, B.M.. 2004. The Central Asian orogenic belt and growth of the continental crust in the
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Tectonic Evolution of China. Geol. Soc. London, Special Publications, 226, 73-100.
Kröner, A., Windley, B.F., Badarch, G., Tomurtogoo, O., Hegner, E., Jahn, B.M., Gruschka, S.,
Khain, E.V., Demoux, A. & Wingate, M.T.D., 2006. Accretionary growth and crust-formation
in the central Asian Orogenic Belt and comparison with the Arabian-Nubian shield. In: R.
Hatcher (ed.) 4-D Framework of the Continental Crust - Integrating Crustal Processes through
Time, Memoir, Geol. Soc. America, in press.
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Perello, J., Cox, D., Garamjav, D., Sanjdori, S., Diakov, S., Schissel, D. Munkhbat, T. & Oyun, G.
2001. Oyu Tolgoi, Mongolia: Late Siluro-Early Devonian porphyry Cu-Au-(Mo) and highsulphidation
Cu mineralization with a Cretaceous chalcocite blanket. Econ. Geol., 96, 1407-
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Ruzhentsev, S.V., and Mossakovskiy, A.A. 1996. Geodynamics and tectonic evolution of the
Central Asian Paleozoic structures as the result of the interaction between the Pacific and Indo-
Atlantic segments of the Earth: Geotectonics, 29, 294-311.
Sengör, A.C., Natal’in, B.A, and Burtman, V.S., 1993. Evolution of the Altaid tectonic collage and
Palaeozoic crustal growth in Eurasia. Nature, 364, 299-306.
Thybo, H, Nielson, C., Jensen, M.-B., Suvorov, V.D., and Perchuc, E., 2006, Baikial explosion
seismic transects, (abs), 12th International Symposium on Deep Seismic Profiling of the
Continents and Margins, Hayama, Japan.
Tomurtogoo, O., Windley, B.F., Kröner, A., Badarch, G. & Liu, D.Y. 2005. Zircon age and
occurrence of the Adaatsag ophiolite and Muron shear zone, central Mongolia: constraints on the
evolution of the Mongol-Okhotsk ocean, suture and orogen. J. Geol. Soc. London, 162, 125-134.
Wang, Y., Mooney, W.D., Yuan, X. & Coleman, R.G. 2003. The crustal structure from the Altai
mountains to the Altyn Tagh fault, northwest China. J. Geophys., Res., 108, B6, 2322,
doi:10,1029/2001JB000552, 7/1-16.

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Wickham, S.M., Albertz, A.D., Zanvilevich, A.N., Litvinovsky, B.A., Bindeman, I.N., Schauble,
A., 1996. A stable isotope study of anorogenic magmatism in East Central Asia. J. Petrol. 37,
1063-1095.
Windley, B.F., Alexeiev, D., Xiao, W., Kröner, A., and Badarch, G., 2006. Tectonic models for
accretion of the Central Asian orogenic belt. J. Geol. Soc. London, in press.
Xiao, W., Windley, B.F. Hao, J. and Zhai, M., 2003. Accretion leading to collision and the Permian
Solonker suture, Inner, Mongolia, China: termination of the central Asian orogenic belt.
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Tectonophysics, 359, 307-327.

ERAS Report for 2006 – Annexure 6
Geological Society, Special Publication – supported by the
International Lithosphere Program (ILP)
Title: Accretionary Orogens in Space and Time
Editors: Peter A. Cawood 1 and Alfred Kröner 2
1 Tectonics Special Research Centre, University of Western Australia, 35 Stirling
Highway, Crawley, WA 6009, Australia
e-mail pcawood@tsrc.uwa.edu.au
2 Institut für Geowissenschaften, Universität Mainz, 55099 Mainz, Germany
e-mail kroener@mail.uni-mainz.de
Meeting:
The proposed articles for this special publication are based on invited contributions by
recognized experts but the initial idea for such a volume grew out of discussions at
symposia held at the Supercontinents and Earth Evolution meeting in Perth,
September 2005, GSA Salt Lake City, October 2005, and EGU, April 2006.
Background and aims:
Classic models of orogens involve a Wilson cycle of ocean opening and closing with
orogenesis related to continent-continent collision. Such models fail to explain the
geological history of a significant number of orogenic belts throughout the world in
which deformation, metamorphism and crustal growth took place in an environment
of ongoing plate convergence. These belts are termed accretionary orogens but have
also been refereed to as non-collisional or exterior orogens, Cordilleran-, Pacific-,
Miyashiro-, and Turkic-type orogens.
This book aims to bring together key researchers on Accretionary Orogens in
providing an up to date understanding of the both the processes operating in
accretionary orogens and the distribution and character of these orogens in space and
time.
What are accretionary orogens:
Accretionary orogens form at sites of subduction of oceanic lithosphere and consist of
magmatic arcs systems along with material accreted from the downgoing plate and
eroded from the upper plate. Accretionary orogens have been active throughout Earth
history. They have been responsible for major growth of the continental lithosphere
through the addition of juvenile magmatic products and include Archean greenstone
belts, the Paleoproterozoic Birimian orogen (W. Africa), the Arabian-Nubian shield
(Pan African) and Paleozoic orogens in Asia. They are also major sites of
consumption and reworking of continental crust through time (e.g. Andean margin)
and understanding the balance between crustal generation and consumption in
accretionary orogens is fundamental to resolving models of continental growth
throughout Earth history. Orogenesis takes place through coupling across the plate

oundary with strain concentrated in zones of mechanical and thermal weakening
such as the magmatic arc and back arc region. Potential driving mechanisms for
coupling include accretion of buoyant lithosphere (terrane accretion), flat slab
subduction, and rapid absolute upper plate motion over-riding the downgoing plate.
The Circum-Pacific region provides outstanding examples of accretionary orogens.
2
The book will appeal to a wide variety of researchers reflecting the diverse interests of
those working on accretionary orogens. It will be particular relevant to those in the
field of tectonics.
We have broken the proposed articles into two broad headings: those concerned with
processes operating in accreting orogens and those concerned with understanding
specific orogens through space and time.
Proposed Papers
Overview and Processes
1. Accretionary Orogens in Space and Time – P.A. Cawood and A. Kröner
2. Metamorphic Patterns in Accretionary Orogens – Mike Brown
3. Seismic Images of Accretionary Orogens – implications for lithosphere
structure and development – Larry Brown & Bruce Goleby
4. Magmatic Patterns and Geochemical Signature of Accretionary Orogens –
Rob Kerrich and A. Polat,
5. The rock and sediment fabric of modern subduction zones predict that
truncated, thinned, and missing convergent-margin crust may be typical of the
suture zones of ancient accretionary orogens. David Scholl and Roland von
Huene.
6. Sedimentary Evidence for Large-Scale Crustal Recycling at Active Plate
Margins – Peter Clift
7. Thermo-mechanical modeling of crustal reworking and the balance between
crustal accretion and subtraction at subduction-related orogens – S. Sobolev
8. Geodynamic modelling of accretionary orogens – Klaus Regenauer-Lieb
9. Preservation and destruction of subcontinental lithosphere beneath
accretionary orogens – W.L. Griffin, S.Y. O'Reilly, O. Alard and J. Zheng
10. Driving mechanisms of deformation in accretionary orogens – Gordon Lister
11. Ocean plate stratigraphy past and present – Brian Windley and Sigenri
Maruyama
12. Unraveling the nature and causes of arc-backarc migration patterns in
accretionary orogens using geochemistry: the Lachlan Fold Belt example –
Bill Collins
13. Metallogeny of accretionary orogens - the connection between lithospheric
processes and endowment. Frank Bierlein, David Groves and Peter Cawood

Regional Studies
14. Earth’s earliest Accretionary Orogens – Friend and Nutman
3
15. Archean accretionary orogens in Australia: comparisons with modern
orogens" authored by K. Cassidy, M. van Kranendonk, H. Smithies and D.
Champion
16. Accretionary history of the Superior Province - M. Sanborn-Barrie, G. M.
Stott, T. Skulski and D. White
17. Correlation of Archean to Mesoproterozoic units between Canada and
Greenland: Constraining the accretionary history of Trans-Hudson Orogen
within an upper plate/lower plate Asian (Himalayan) context for the
Proterozoic. Marc R. St-Onge, Jeroen van Gool, Adam A. Garde, and David J.
Scott.
18. Palaeoproterozoic accretionary processes in Finland – Raimo Lahtinen
19. Reworking of Palaeoproterozoic accretionary orogens in Laurentia – David
Corrigan, Karl Karlstrom and Fred Cook
20. The Timanian accretionary margin of Baltica –Johannes Glodny and Vicky
Pease
21. Evolution of the Central Asian Orogenic Belt: constraints from
geochronology, palaeomagnetism and field relationships. A. Kröner, B.F.
Widley, W.J. Xiao, P. Jian , D. Alexeiev and A. Didenko.
22. Structural evolution of Arctic Eurasia and Altaid orogeny. Vicky Pease and
Scott
23. Lachlan Fold Belt accretionary orogen – David Gray, Dave Foster, Bob
Gregory
24. Accretionary processes in the Canadian Cordillera – Stephen Johnson
25. Proto-Andean accretionary processes in the South American Cordillera –
Ricardo Astini
26. Accretionary processes in the Caribbean - Manuel Itturalde et al.
27. Canadian Cordillera – Geophysical perspective. David Snyder et al.
28. Accretionary processes in SE Asia – Robert Hall
29. Phanerozoic accretionary orogen in Japan: a template for Precambrian
analogues - Yukio Isozaki