radiolaria - Marum

Radiolaria 14 Bibliography - 1993
however, were also relatively small and would not be expected to
bias the sedimentary record toward restricted periods of higher
radiolarian output. Comparison of the present data with detailed
previous information for the Gulf of Alaska shows that both total
radiolarian flux, and its intermittence throughout the year, are very
similar in the two areas.
Boltovskoy, D., Alder, V.A. & Abelmann, A.
1993. Radiolarian sedimentary imprint in Atlantic equatorial
sediments: Comparison with the yearly flux at 853m. Mar.
Micropaleontol., 23/1, 1-12.
Radiolarian specific compositions in a series of 20 sediment
trap samples covering an entire year (1.3.1989 to 16.3.1990,
collected at 853 m) were compared with bottom (0-1 cm) materials
from the same site (eastern equatorial Atlantic: 01°47.5'N,
11°07.6'W). Data on mean sediment accumulation rates at the site
of the mooring (I.59 -g/cm 2 /kyr), mean radiolarian flux at 853 m
(28,446 shells/m 2 /day), and abundance in the 0-1 cm bottom layer
(48,258 shells/g) suggest that approximately 95% of the
radiolarians produced are lost to the fossil record. Sediment trap
sample-to-sample correlations (based on relative abundances of 40
radiolarian species present at levels ≥1% in at least one sample,
mean value, r=0.886) did not differ significantly from correlations
between each water column sample and surface sediments (mean
r=0.878). Similarities between the flux and the sediments were not
associated with time of year and with periods of enhanced
radiolarian output. Two taxa had lower, and nine taxa had higher
percentage contributions in the sediments than in any one sediment
trap sample, and a few of the abundant species had averages up to 7
times higher in either the water column or the sediments. These
dissimilar percentage loadings are attributed to selective
dissolution, lateral subsurface and deep advection of shells from
higher-latitude areas, and identification biases. As opposed to
species-level inventories, family-level databases (including shells
identified to family only ) differed significantly between the water
column and the sediments. Spumellaria (especially Spongodiscidae)
were more abundant in the sediments (35%) than in the water
column (19%), while Nassellaria showed the opposite trend (64%
and 80%, respectively). It is suggested that ease of identification of
spongodiscid fragments and fragility of juvenile nassellarians are
responsible for these differences.
Braun, A. 1993. Die Anwendung der Radiolarien-
Biochronologie auf Gesteine des Thüringischen Unterkarbons
- Ergebnisse und Möglichkeiten. Geol. Jb. Hessen, 121, 11-
16.
Radiolarian faunas from Phosphorite-concretions of the
"Ruβschiefer" and from Siderite concretions ("Kieskälber") of the
roof slates in the Thuringian Lower Carboniferous allow dating and
correlation of the Thuringian sediment series with those of the
eastern Rheinisches Schiefergebirge. The level of the "Ruβschierer"
contains the same Radiolarian zones as the "Liegende
Alaunschiefer" of the Rheinisches Schiefergebirge. The deeper part
of the "Dachschierer-Folge" corresponds biostratigraphically to the
deeper part of the "Schwarze Lydite" of the Rheinisches
Schiefergebirge.
Braun, A. & Amon, E.O. 1993. A rapid technology of
detecting and preliminary investigating of radiolarians in
field work conditions. Paleont. Z., Akad. Nauk SSSR, 2, 122.
(in Russian)
A method for etching the surfaces of various sedimentary
rocks, including radiolarian. cherts, in field-work conditions is
proposed. Solution of hydrofluoric acid can be used for this
procedure.
Braun, A. & Schmidt-Effing, R. 1993. Biozonation,
diagenesis and evolution of radiolarians in the Lower
Carboniferous of Germany. In: Interrad VI. (Lazarus, D.B. &
De Wever, P., Eds.), vol. 21/4. Special Issue: Marine
Micropal., Elsevier, Amsterdam. pp. 369-383.
Based on radiolarian faunas recovered from sequences of
siliceous shales and dark claystones in the Lower Carboniferous of
the Rheinisches Schiefergebirge (Germany), a radiolarian biozonation
is proposed. Diagenetic alteration of faunas is documented and the
stratigraphic distribution of more resistant taxa is given. For closely
spaced samples a gradual shift of morphotype abundance has been
found for Albaillella cartalla in the Visean, but no gradual transition
between species of Albaillella has been found.
Carter, E.S. 1993. Biochronology and paleontology of
uppermost triassic (Rhaetian) radiolarians, Queen Charlotte
- 95 -
Islands, British Columbia, Canada. Mem. Geol. (Lausanne),
vol. 11, 1-175.
A rich radiolarian fauna of Rhaetian age has been recovered
from limestone concretions in strata of the Sandilands Formation at
localities on northwest Graham Island (Kennecott Point), Louise
Island, Skidegate Inlet, and Kunga Island, Queen Charlotte Islands,
British Columbia. Unusually thick stratigraphic sections at
Kennecott Point and Kunga Island record continuous sedimentation
through latest Triassic and earliest Jurassic time. Independent
dating is provided by conodonts that co-occur in many radiolarian
samples and rare ammonoids that are associated at several levels.
New radiolarian zonation for the Rhaetian defined by Unitary
Associations (UA.; Guex 1977, 1991) is presented. A database
recording the appearance of 136 species in 69 superposed horizons
or samples of 6 sections was used to establish 27 successive U A.,
with each U A. defined by the totality of its characteristic species.
UA's. were grouped into 6 distinct assemblages (biochronozones)
whose terminology follows Carter 1990.
The late Norian Betracciun deweveri Zone (Blome 1984) ranges
into post-Monotis basal strata of the Sandilands Formation (late
Norian or earliest Rhaetian). Immediately above this zone, three
successive radiolarian assemblages occur whose age is correlated
with Late Triassic ammonoid biochronology of Tozer (1979).
Assemblage 1, the lower one, approximates the lower part of the
Amoenum Zone; Assemblage 2 (with four subassemblages)
approximates the middle and upper Amoenum Zone; and Assemblage
3 is correlated with the uppermost Triassic Crickmayi Zone.
Two formal zones are established which allow worldwide
correlation of the Rhaetian using radiolarians. Their ages are
correlative with the Late Triassic ammonoid biochronology of Tozer
(1979). The Proparvicingula moniliformis Zone contains radiolarians
of Assemblage 1 and Assemblage 2 (this study); it represents the
lower Rhaetian and is approximately equivalent to the Amoenum
Zone. The Globolaxtorum tozeri Zone contains radiolarians of
Assemblage 3 (this study); it represents the upper Rhaetian and is
equivalent to the Crickmayi Zone.
All radiolarian species used in the zonation are discussed along
with a few others having more limited occurrence. Species previously
described and/or figured in the literature are discussed in terms of
their occurrence in Queen Charlotte Islands. One family, five genera
and 63 species are described as new.
Casey, R.E. 1993. Radiolaria. In: Fossil Prokaryotes and
Protists. (Lipps, J.H., Eds.). Blackwell Scientific
Publications, Oxford/London. pp. 249-284.
Radiolaria are marine, holoplanktic protozoans belonging to the
superclass Actinopodea of the subphylum Sarcodina. The term
radiolaria itself is now used informally. In the fossil record, only the
class Polycystinea (or polycystine) encompassing the orders
Spumellar (spurnellarians) and Nassellar (or nassellarians), which
possess solid opaline skeletal structures, and the order Phaeodarea
(or phaeodarians), which possess hollow skeletal structures of an
admixture of silica and organic matter, are preserved. Radiolarian
skeletons range in size from about 50 to 200 µm. The class
Acantharea (or acantharians) are common in nearshore waters and
are sometimes involved in plankton blooms, but they are never
preserved as fossils. Herein, radiolaria refers to both members of
the Polycystina and the Phaeodara. The polycystine radiolarians have
the longest geologic range (Cambrian to Holocene), the widest
biogeography (pole to pole, surface to abyss), and the most diverse
taxonomy of the well-preserved microzooplankton. They are used
extensively in biostratigraphy, in paleoceanography, and in studies
on the tempo and mode of evolution. Phaeodarians may be used to
infer various water and geologic conditions. The history of
radiolarian research can be separated into six periods: an early
recognition of the group in both living and fossil forms; work by Ernst
Haeckel; early work on living forms; a resurgence of radiolarian work
by William Riedel; radiolarian work associated with the Deep Sea
Drilling Project (DSDP) and the Ocean Drilling Program; and the
current diverse modern work.
Caulet, J.P., Nigrini, C. & Schneider, D.A. 1993.
High resolution Pliocene-Pleistocene radiolarian stratigraphy
of the tropical Indian Ocean. Mar. Micropaleontol., 22/1-2,
111-129.
We refined the positions of 31 Plio-Pleistocene radiolarian
datum levels by examining 3 paleomagnetically dated cores and
comparing results with 4 previously studied cores from the Central
Indian Basin. When not affected by hiatuses or drastic changes in
rates of sedimentation, absolute ages of radiolarian events in
multiple cores from this restricted geographic area are precise to
within 0.05 million years. Some events are complicated by minor
morphotypic changes at the beginning or end of ranges or within
evolutionary lineages; species definitions have to be restricted