radiolaria - Marum

Bibliography - 1991 Radiolaria 14
We recommend reduction to informal status for the Coffee
Creek (Mississippian), Spotted Ridge (Pennsylvanian?), and Coyote
Butte (Permian) formations because (13 they cannot be mapped or
traced beyond limited areas, and (2) these older rocks are
chaotically intermixed with younger chert and volcaniclastic rocks.
New biostratigraphic data indicate that the bulk of the Spotted Ridge
volcaniclastic rocks represent a part of the Triassic Vester
Formation of the Izee terrane.
Boltovskoy, D. 1991. Holocene-upper Pleistocene
radiolarian biogeography and paleoecology of the Equatorial
Pacific. Palaeogeogr. Palaeoclimatol. Palaeoecol., 86/3-4,
227-241.
Polycystine radiolarians were investigated in 66 samples from
5 box-cores spanning the last ca. 40,000 years from the western
(approx. 160°E) and the central (136°W) equatorial Pacific. The
assemblages investigated show clear differences associated with
the geographic locations of the sites: the central Pacific is
characterized by higher specific diversities. much higher absolute
abundances of shells per gram of dry bulk sediment, and by
conspicuously better radiolarian preservation. The differences
involved also include significant changes in the relative proportions
of several radiolarian species (these accounting for approx. 25% of
total individuals). families and orders. These dissimilarities are
chiefly attributed to differences in the primary production of the two
zones and to enhanced advection of colder-water species
characteristic of the California Current to the central equatorial
Pacific. In both areas, downcore faunal changes, if present at all, are
so weak that background noise from random sample-to-sample
variations almost completely masks them. There do not seem to be
any noticeable shifts associated with the 18 k.y. B.P.level.
Inconclusive evidences of environmental changes at 30-20 k.y. B.P.
are suggested in some of the cores by the increase in the
proportions of several species characteristic of colder northeastern
Pacific waters and by lower radiolarian accumulation rates; these
changes seem to be paralleled by shifts in the isotopic composition
of planktonic Foraminifera.
Bragin, N.Y. 1991. Radiolaria and lower mesozoic units of
the USSR East regions. Transactions, Nauka 469, 1-122 p.
(in Russian)
The stratigraphic distribution of microfauna in sequences has
been analysed on the material of Sikhote-Alyn, Sakhalin and Koryak
Upland. 7 zones and stratigraphic layers with radiolarians and 17
zones and stratigraphic layers are established at Sikhote-Alyn in
interval from the middle part of Lower Triassic to Triassic—Jurassic
boundary. Several zones are traced at Sakhalin and Koryak Upland;
the correlation with sequences of Mediterranean area, USA and
Japan is realised. The development of radiolarian assemblages in
Triassic is studied. On the base of new stratigraphic data the idea of
small thickness and, in opposite, great stratigraphic volume of chert
units was formulated, then, the Triassic paleogeography of northeast
Asia has been analysed, conditions of chert units formation
were discussed and its paleooceanic origin has been supposed.
Bragin, N.Y. 1991. Carnian radiolarian complex of
volcanogenic siliceous formations of the Ekonay zone in the
Koryak Upland. Izv. Akad. Nauk SSSR, ser. geol., 6, 79-86.
(in Russian)
Consecutive complexes of radiolaria, ranging from Carnian to
late Norian-Rhaetian (?), were discovered in the section from
volcanogenic-siliceous formations on the river Podgornaya. They are
similar to Radiolaria known in other regions in the east of the USSR.
An exception is an association of late Carnian age with
Capnuchosphaera deweveri etc. which is more similar to complexes
from the Mediterranean and has as yet no clear analogues in the
USSR. This association includes a new species, Bernoullius (?)
capricornus sp. nov. which is described
Bragina, L.G. 1991. Radiolarians from the Bystrinsk
sequence Santonian-Campanian of northwest Kamchatka.
Seriya Geologicheskaya, 7/7, 129-136. (in Russian)
Braun, A. & Amon, E.O. 1991. Fluoritisierte
Radiolarien aus Kieselkalk-Banken des Mittel-Viseum
(Unterkarbon) des Rheinischen Schiefergebirges
(Deutschland). Paläont. Z., 65/1-2, 25-33.
From siliceous shales (Lower Carboniferous, Rheinisches
Schiefergebirge), in direct neighborhood to a bed of allodapic
limestone, the following fluoritized radiolarian fauna has been
extracted by chemical transformation of originally calcified
skeletons: Albaillella cartalla, Latentifistula turgida, Eostylodictya
cf. eccentrica, Tetragregnon sycamorensis sycamorensis, Belowea
variabilis, Callela ? hexactinia, Entactinia tortispina and Entactinia
- 60 -
variospina. The limestone bed has been dated by calcareous
foraminifera as being mid Visean in age (V 2b-3a, Cf 5-foraminiferal
zone). The diagenetic calcification took place after the selective
dissolution of the skeletons and was in itself not selective.
Braun, A. & Gursky, H.J. 1991. Kieselige
sedimentgesteine des unter-Karbons im Rhenoherzynikum -
eine bestandsaufnahme. Geologica et Paleontologica, 25,
57-77.
Based on published and own data, the state-of-the-art of
investigation on Lower Carboniferous siliceous-rock bearing
sedimentary sequences in Central Europe is briefly reviewed.
Regional occurrence, lithology, sedimentology, petrography, fossil
content, and age are addressed. Four stratigraphic levels are mostly
or partly represented by siliceous rocks in the northern and eastern
Rheinisches Schiefergebirge, Kellerwald, Upper and northern Middle
Harz areas:
D) Siliceous Transitional Beds (Kieselige Übergangsschichten;
cu Go α),
C) Light-Coloured Cherts/Cherty Limestones (Helle/Bunte
Kieselschiefer/ Kieselkalke; cu Pe ∂)
B) Black Cherts (Schwarze Kieselschiefer/Lydite; cu Pe ß-γ),
A) Lower Alum Shales (Liegende Alaunschiefer; cu ?Ga-Pe α).
A correlation scheme of goniatite, conodont, foraminiferal and
radiolarian biostratigraphy of the Rhenohercynian Lower
Carboniferous is presented. Partly Corg-rich ribbon cherts and slaty
siliceous mudstones as well as metabentonites and fine- grained
turbiditic limestones alternate to form the rhythmical bedding of the
sequences. Laminations and diagenetical deformations of the
bedding are characteristical. The siliceous rocks are mainly
composed of quartz/chalcedony and very fine-grained siliciclastic
detritus; radiolarians and sponge spiculae are abundant, but variably
preserved. Recrystallization and pressure solution of different
grades are typical. The metabentonite layers mainly consist of
mixed-layer clay minerals and partly contain volcanogenic relics.
SEM, X-ray diffractometry and chemical data complete the
petrographic analyses. Detailed study of the radiolarians contributes
to the interpretation of deposition, diagenesis and ecology of the
original sediments. The discussion on the origin and the
paleogeography are sketched.
Carter, E.S. 1991. Late Triassic radiolarian
biostratigraphy of the Kunga Group, Queen Charlotte Islands,
British Columbia. In: Evolution and Hydrocarbon Potential
of the Queen Charlotte Basin, British Columbia. Eds.), vol.
90-10. Geological Survey of Canada, Paper, pp. 195-201.
Diverse, well preserved Upper Carnian and Norian radiolarians
are present in the Peril and Sandilands formations of the Kunga
Group, Queen Charlotte Islands. Ammonoids, bivalves, and conodonts
are associated with most radiolarian assemblages. The oldest f
faunas are Late Carnian and occur with ammonoids from the Lower
Welleri Zone. Capnodoce De Wever is rare in these assemblages but
becomes more abundant and diverse in uppermost Carnian ones.
Described radiolarian species from eastern Oregon, western Europe,
and the Mediterranean area are present in all samples, but the
majority of taxa (particularly Upper Carnian) are new.
Capnodoce fragilis Blome, Harsa siscwaiensis n. gen. n. sp., and
Xiphosphaera fistulata n. sp. are abundant in upper Lower Norian to
lower Middle Norian strata of the Queen Charlotte Islands. This
three-fold radiolarian association is a useful marker for this interval
of time; it has not been found in older or younger assemblages. Two
new species and one new genus are described in this report.
Upper Norian radiolarians of the Betraccium deweveri Subzone
are present in the Monotis beds of the uppermost Peril Formation.
Three informal Upper Norian radiolarian assemblages have been
proposed for post- Monotis strata of the overlying Sandilands
Formation.
Carter, E.S. & Jakobs, G.K. 1991. New aalenian
Radiolaria from the Queen Charlotte Islands, British
Columbia: implications for biostratigraphic correlation.
Geol. Surv. Canada, curr. res., Pap., 91-1A, 337-351.
This is a preliminary report on diverse, well preserved Aalenian
radiolarians that have been found in a carbonate concretion from the
belemnite sandstone member of the Phantom Creek Formation on the
Yakoun River, Queen Charlotte Islands. The sample is associated with
an Aalenian ammonite fauna that is previously unknown from this
area and indicates a probable early late Aalenian age for the
radiolarian sample. This faunal association extends the range of
known Toarcian and Aalenian radiolarians, documents the presence
of widely known taxa from other areas whose age may be equivalent