radiolaria - Marum

Bibliography - 1990 Radiolaria 14
Paleozoic fusulinids-corals and Triassic corals and other fossils
from limestone blocks and the Late Jurassic marine fauna of the
Torinosu Group. However, since the end of 1970s, as soon as it was
recognized that this terrane is abundant in rocks yielding wellpreserved
microfossils, especially radiolarians, great efforts have
been made to carry out the reexamination of stratigraphy, geologic
structure and geologic age mainly by means of radiolarian
biostratigraphy. As a result, our knowledge of this terrane has been
rapidly advanced
Matul', A.G. 1990a. Radiolaria thanatocenosises of
sediment surface layer in the North Atlantic as reflection of
environmental conditions. Okeanologiya, 30/1, 102-107.
(in Russian)
Four climatic groups of radiolarians, characterised by their
attribution to some intervals of yearly average surface water
temperature (subarctical, boreal, subtropical and tropical), are
distinguished using data on quantitative distribution in surface
sediment layer of 31 abundant species. Accordingly to changes of
interrelations of these climatic groups in the modern
thanatocoenoses the types of radiolarians thanatocoenoses are
revealed, regions of which spreading are correspondent to climatic
zones of the North Atlantic.
Matul', A.G. 1990b. Radiolaria thanatocenoses in the
surface layer of the North Atlantic sediments as a reflection of
natural environmental conditions. Oceanology, 30/1, 76-79.
On the basis of data on the quantitative distribution of 31 very
common species in the surface layer of the sediments, four climatic
groups of radiolarians are distinguished, each of them characterized
by confinement to particular intervals of the mean annual
temperature of the surface water: subarctic, boreal, subtropical and
tropical. From the changes in ratios of these groups in the Recent
thanatocenoses, types of Radiolaria thanatocenoses were found,
whose geographic ranges in the sediments on the whole correspond
to the climatic zones of the North Atlantic. By the graphs of the
distribution of climatic groups in the Recent sediments, it appears to
be possible to reconstruct the paleotemperatures by studying the
paleothanatocenoses. The accuracy of the method is: ≤ ± 1,0° in 64-
76%, ≤ ±1,5° in 75-80%, and ≤ ±2,0° in 84-92% of the
calculations.
Michalik, J., Gasparikova, V., Halasova, E.,
Petercáková, M. & Ozvoldová, L. 1990.
Microbiostratigraphy of the Upper Jurassic and Lower
Cretaceous formations in the Manín unit, Mt. Butkov section
(Strazovské Vrchy Mts., central West Carpathians). Knih.
zemního plynu a nafty, 96, 23-55. (in Czech)
This paper is a continuation of systematic stratigraphical
research of Upper Jurassic—Lower Cretaceous sequence In the
Butkov section. Several results Or study o~ ammonites, belemnites,
crinoids, tintinnids and other calcareous microplankton have been
published in the last years (Vasicek et al., 1983; Vasicek &
Michalik, 1988; Borza et al., 1987; Zitt & Michalik,1988, Michalik &
Vasicek, 1989 etc). This contribution is focused on the
microplankton and nannoplankton remnants.
The radiolarians occur in all the formations studied. However,
only uncalcified radiolarians have been able to be separated and
identified. The radiolarian associations from Czajakowa, Ladce,
Mraznica, Kalisco, and Luckovska Formations were the best
preserved. Those of the Czajakowa Formation represent Late
Oxfordian U.A.7 and U.A.8. Ladce and Mraznica Formations contain
dispersed, often poorly preserved radiolarians of general Lower
Cretaceous type. 26 radiolarian species belonging to Late Early
Hauterivian Mirifusus chenodes Zone come from the Kalisco
Formation. The richest associations (38 radiolarian taxa) have been
obtained from the Luckovskci Formation. Except of Barremian types,
several Hauterivian species Acanthocircus dicranacanthos, Ac.
carinatus, Obesacapsula rotunda, and Cecrops septemporatus are
present in those associations. They are supposed to be derived from
older limestone clasts.
No nannoplankton have been found in Upper Jurassic beds.
Ladce Formation yielded a poor association dominated by
Waznaueria barnesae, Micrantholithus hochschulzi and Nannoconus
steinmanni. Almost Identical associations occur In both the Mraznica
and Kalisco Formations: sole occurrences of Calcicalathina
oblongata, Conusphaera mexicana, Cruciellipsis cuvillieri enrich
them in the last one. This association could indicate Hauterivian-
Barremian boundary in the upper part of the Kalisco formation. A
similar, even more diversified association comes from the
Luckovska Formation. It Is enriched by Braarudosphaera bigelowi and
by sole Calcicalathina oblongata. Calcitic nannoplankton of all the
formations is represented by robust, thick forms, which were
resistant to dissolution and diagenesis. Cruciellipsis cuvillieri and
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Conusphaera mexicana have been here described for the first time
from the west Carpathian territory. The former one is a valuable
Early Berriasian—Late Hauterivian Index species. The facts obtained
make the biostratigraphical knowledge of the Upper Jurassic—Lower
Cretaceous sequence in the Manin Unit (and in the West Carpathians
as a whole) more complete. However, refining of Lower Cretaceous
nannoplankton biostratigraphical scale needs further, more detailed
study with the use of S.E.M.
Mizutani, S. 1990. Mino Terrane. In: Pre-Cretaceous
Terranes of Japan. Publication of IGCP Project No. 224: Pre-
Jurassic Evolution of Eastern Asia. (Ichikawa, K., Mizutani,
S., Hara, I., Hada, S. & Yao, A., Eds.). IGCP Project 224,
Osaka, Japan. pp. 121-135.
Murchey, B.L. 1990. Age and depositional setting of
siliceous sediments in the upper Paleozoic Havallah sequence
near Battle Mountain, Nevada; implications for the
paleogeography and structural evolution ofthe western
margin of North America. Geol. Soc. Amer., spec. Pap., 255,
137-155.
The upper Paleozoic Havallah sequence of central Nevada is a
folded and thrust-faulted association of greenstone, siliceous
marine sedimentary rocks, and deepwater clastic rocks. Microfossil
assemblages (radiolarians, sponge spicules, and conodonts as tools
to unravel the stratigraphy and to interpret the paleoenvironments
of the siliceous sedimentary rocks. Nine radiolarian assemblages
(Osagean to Guadalupian) are described and used for delineation and
correlation of fault-bounded lithotectonic units. The biostratigraphic
zonation reveals that the oldest rocks in each lithotectonic unit are
progressively younger from the structurally highest to the lowest
units, suggesting progressive west-to-east upsection stepping of
the Golconda sole thrust with accretion of each unit. Analyses of the
radiolarian and sponge spicule faunas permit lateral and temporal
comparisons of depositional environments. The lower structural
units are coarsening-upward sequences of hemipelagic slope
deposits overlain by sponge spicule-rich turbidites derived from a
shallow source. The uppermost structural unit is a coarseningupward
basinal sequence. Permian sponge spicules in turbidites of
the slope sequences and redeposited fusulinids in the basin
sequence are similar to those in adjacent autochthonous (North
American) regions. Permian radiolarians and sponge spicules in
hemipelagic siliceous argillite of the slope sequences are similar to
those in the Northern Sierra terrane to the west; the Havallah basin
and the Northern Sierra arc terrane were overlain, therefore, by a
similar water mass and may have been in proximity during the
Permian. Clastic dikes and sills containing volcanic, metamorphic,
and sedimentary rock clasts are Leonardian or younger.
Nagai, H. 1990. Jurassic (Lower Toarcian) Radiolarians
from the Hyde Formation, central Oregon, North America.
Bull. Nagoya Univ. Furukawa Mus., 6, 1-19. (in Japanese)
Radiolarian fossils in the Jurassic (lower Toarcian) Hyde
Formation of Oregon were examined. It is detected that the
radiolarians belonging to Eucyrtidiellum sp. C group of Nagai (1986)
are contained in sample OR-600 in the lower part of the Hyde
Formation. E. sp. C 2 seems to be a marker species which indicates a
stratigraphic horizon ranging in age from upper Pliensbachian to
lower Toarcian.
Nagai, H. & Mizutani, S. 1990. Jurassic Eucyrtidiellum
(Radiolaria) in the Mino Terrane. Trans. Proc. palaeont. Soc.
Japan, n. Ser., 159, 587-602.
Jurassic Eucyrtidiellum in chert, siliceous shale and manganese
carbonate rock in the Mino terrane of central Japan was studied
together with that of the Snowshoe Formation of Oregon with the
result that eighteen species are recognized in the early Late to
Upper Jurassic formations. Of all these species, Eucyrtidiellum
disparile, E. unumaense, E. pustulatum, E. semifactum and E. ptyctum
are most prevalent. These species are morphologically related with
each other, and show an evolutionary trend composed of two
consecutive steps of change, early in shell structure of abdomen,
represented by transition from E. disparile to E. unumaense and later
in superficial plication of abdomen, represented by transition from E.
pustulatum through E. semifactum to E. ptyctum. On the basis of
occurrence of E. pustulatum in the upper Bathonian part of the
Snowshoe Formation, radiolarian biostratigraphical correlation for
the Japanese Jurassic formations is discussed. Two new species,
Eucyrtidiellum disparile and E. semifactum, are described in this
paper together with other species relevant to them.
Nakae, S. 1990. Melanges in the Mesozoic sedimentary
complex of the northern part of the Tamba Belt, southwestern
Japan. J. geol. Soc. Japan, 96/5, 353-369. (in Japanese)