radiolaria - Marum

Radiolaria 14 Bibliography - 1989
listed exist. Clay minerals, calcite, and hematite make up the
radiolarite impurities. Smectite, illite, and locally kaolinite are the
clay minerals present, smectite always being most abundant. No
radiolarite bed with more than 85% silica has been found; the total
SiO2 content ranges from 61 to 85% . Frequently the compact
appearance of the radiolarite results from a high carbonate content.
The ratios Si/Si + Al + Fe + Ca, Si/Si + Al + Fe, and Al/Al + Fe + Mn
are calculated and used to compare the beds of couplets in rhythmic
sequences and to obtain the relative distance of sections from their
terrigenous source. These three chemical indices do not give
consistent results. Fe enrichment of radiolarite relative to siliceous
mudstone is probably related to the }ow mean sedimentation rate of
these sequences from the Subbetic (3.5 mm/l000 y). Pelagic
settling in a basin with irregular bottom topography and with areas
topographically protected from sediment input is proposed for
deposition of these deposits. Productivity cycles and terrigenous
dilution gave rise locally to rhythmically bedded sequences, usually
composed of radiolarite-mudstone alternations. Locally, contour and
distal dilute turbidity currents reworked and deposited the sediment,
and gave rise to thin sequences of layered sedimentary rocks and to
laminated beds. Deposition above a relatively shallow CCD is
deduced, and a water depth shallower than previously thought is
suggested for these deposits, which are considered as the deepest
water deposits of the Betic External Zones.
Saito, M. 1989. Jurassic melanges in the Taniguni area,
Gifu Prefecture, Mino terrane. J. geol. Soc. Japan, 95/8, 579-
594. (in Japanese)
Jurassic melanges in the Tanigumi area of the Mino terrane
consist of three units, i.e. melange I, II and m Melange I includes
exclusively sandstone-blocks whereas melange II is characterized by
chert-, shale-, and sandstone-blocks and melange III is by
greenstone-limestone-, dolostone-, chert-, shale- and sandstone
blocks. Biostratigraphic data examined for blocks and matrix in the
southern part of the study area show that the original lithologic
succession of melange II includes the following formations, in
ascending order- middle Permian chert, middle Triassic to late early
Jurassic chert, early middle Jurassic shale, and late middle Jurassic
mudstone and sandstone(?).
Sashida, K., Igo, H., Adachi, S. & Ito, S. 1989.
Radiolarian dating of the Torinosu-type limestone in the
Kanto Mountains, Central Japan. Annu. Rep. Inst. Geosci.,
Univ. Tsukuba, 15, 54-60.
The "Torinosu Limestone" crops out typically a Torinosu,
Sakawa Town, Kochi Prefecture, Shikoku This limestone is an
important constituent of the Torinosu Group, which is one of the
most classical standard lithostratigraphic units of the Upper
Jurassic in Japan. It is mostly black and bituminous and yields
abundant fossils of reef dwellers such as corals, stromatoporoids,
algae, molluscs, brachiopods, echinoids, foraminifers and others. The
geologic age of this limestone has long been thought to be Late
Jurassic based mainly on hexacorals and stromatoporoids. Similar
limestones are known elsewhere in the Outer Zone of the Japanese
Islands and have been called collectively "Torinosu Limestone" or
Torinosu type limestone. Recent studies on the age of the Torinosu
Group and its equivalent of Southwest Japan using radiolarian
biostratigraphy clearly showed that it ranges from Middle Jurassic to
Early Cretaceous (e.g., Matsuoka and Yao, 1985; Suyari and Ishida,
1985; Yasuda, 1989). Aita and Okada (1986), Aita (1987) and
Ishida (1988) also clarified the age of the Torinosu type limestone
using nannofossils in Shikoku. These microfossils indicate early Late
Jurassic to earliest Cretaceous ages. We have been engaged in the
study to confirm detailed dating of the Torinosu-type limestone in
the Kanto Mountains. To date, we found radiolarians in the Torinosu
type limestone embedded in the Hikawa and Gozenyama Formations
of the Southern Chichibu Terrane and in the Oonari and Kosode
Formations of the Ogouchi Group of the Northern Shimanto Terrane.
Foraminifers were also extracted together with a small amount of
radiolarians from the Torinosu-type limestone interbedded in the
Ishido Formation of the Sanchu Cretaceous formations (Fig. 1). We
briefly describe herein these radiolarians extracted by the
hydrochloric acid method and discussed their dating.
Sato, T., Sashida, K. & Kasai, K. 1989. Mesozoic
system in the Yamizo Mountains. Excursion Guide Book,
96th Annual Meeting of the Geological Society of Japan, 31-
54.
Sharma, V. & Sharma, G.K. 1989. Late Miocene to
early Pliocene radiolarian biostratigraphy of Neill Island,
Andaman Sea. J. geol. Soc. India, 34, 76-82.
104 species of Radiolaria are recorded from a Late Miocene-
Early Pliocene sequence exposed at Neill Island. The assemblage
shows presence of a few reworked radiolarian species. The
radiolarian zones proposed for low latitude areas are applicable in
- 39 -
the present study. Two zones, viz.., Didymocyrtis penultima Zone and
Stichocorys peregrina Zone, have been recognized in the sequence.
Based on the study of planktonic Foraminifera of the same sequence
by earlier workers, an integrated scheme of radiolarian and
foraminiferal zones is presented.
Shemesh, A., Mortlock, R.A. & Froelich, P.N.
1989. Late Cenozoic Ge/Si record of marine biogenic opal:
implications for variations of riverine fluxes to the ocean.
Paleoceanography, 4/3, 221-234.
We have determined germanium/silicon ratios in purified
diatoms and radiolarians from siliceous sediments in Holocene core
tops, one late Pleistocene piston core, and four high-latitude DSDP
sites ranging in age from Holocene to Oligocene. Low values of the
ratio are consistent with global weathering regimes dominated by
river silica input to the sea, while higher ratios suggest periods of
enhanced hydrothermal input or reduced fluvial contribution.
Shu, D. & Chen, L. 1989. Discovery of Early Cambrian
Radiolaria and its significance. Sci. China, Ser. B, 32/8,
986-994.
The well-preserved bivalved microfossils collected from the
Lower Cambrian limestone at the Xiaoyang section in Zhenba,
Shaanxi, have proved the oldest known radiolarians by means of the
electron probing analysis and morphological study under the electron
scanning microscope and the observation of the thin section. The
present discovery has shaken the theory that Thaeodaria originated
from Spumellaria. Unlike the Mesozoic and Cenozoic radiolarians
that are planktonic, the Cambrian ones lived as benthos. On the
basis of the chemical composition and morphological features of
these radiolarians a new genus Eoconcharium and a new family
Eoconchariidae are erected.
Spörli, K.B., Aita, Y. & Gibson, G.W. 1989.
Juxtaposition of Tethyan and non-Tethyan Mesozoic
radiolarian faunas in melanges, Waipapa Terrane, North
Island, New Zealand. Geology, 17/8, 753-756.
Red cherts from Kawakawa Bay near Auckland have yielded Late
Triassic and Early Jurassic radiolarians. The cherts occur as blocks
in melanges that have a green argillite matrix containing Middle and
Late Jurassic (Callovian-Oxfordian) radiolarians. The melanges mark
fault zones along which the Waipapa terrane has been imbricated.
Callovian-Oxfordian green argillites are also found in stratigraphic
contact with overlying Kimmeridgian-Tithonian green argillites and
gray terrigenous clastics. The Late Triassic and Early Jurassic
Radiolaria are Tethyan, but me Middle and Late Jurassic faunas are
dominantly non-Tethyan because the two sets of faunas are of lowlaatude
and of high-latitude origin, respectively, or because they
originated in areas of differing ocean productivity. Occurrence of
both Late Triassic and Early Jurassic radiolarians in one red chert
horizon indicates sedimentary reworking.
Stamatakis, M., Dermitzakis, M., Economou-
Amilli, A. & Magganas, A. 1989. Petrology and
Diagenetic Changes in Miocene Marine Diatomaceous
Deposits from Zakynthos Island, Greece. In: Siliceous
Deposits of the Tethys and Pacific Regions. (Hein, J.R. &
Obradovic, J., Eds.). Springer-Verlag, New York. pp. 129-
140.
Stamatakis, M. & Magganas, A. 1989. Thermally
Induced Silica Transformation in Pliocene Diatomaceous
Layers from Aegina Island, Greece. In: Siliceous Deposits of
the Tethys and Pacific Regions. (Hein, J.R. & Obradovic, J.,
Eds.). Springer-Verlag, New York. pp. 141-150.
Suyari, K., Kuwano, Y. & Yamasaki, T. 1989.
Distribution of lithofacies and geological ages in the
Shimanto South Subbelt in Eastern Shikoku. J. Sci., Univ.
Tokushima, 22, 33-57. (in Japanese)
Takahashi, O., Hayashi, N. & Ishii, A. 1989.
Radiolarian fossils from the Masutomi Group, southwestern
part of the Kanto Mountains, central Japan, and their
significance. J. geol. Soc. Japan, 95/12, 953-955. (in
Japanese)
Takahashi, O., Imai, H. & Ishii, A. 1989.
Occurrence of Cretaceous radiolarians from the Otaki Group,
Kanto Mountains, central Japan. J. geol. Soc. Japan, 95/6,
483-486. (in Japanese)