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Archive · collection · 2006

Visual description and Radiolarian abundance estimates of ODP Hole 200-1223A sediments

Listed in PANGAEA

Among the groups of oceanic microfossils, only Radiolaria occur in abundances and preservation states sufficient to provide biostratigraphic control for restricted intervals within sediments recovered in Hole 1223A.

Description

The distribution of these microfossils has been divided into four major intervals, A-D. Radiolaria distribution Interval A occupies the depth range 0-3.0 meters below seafloor (mbsf), where the abundance of specimens is very low and preservation is poor.

Radiolaria distribution Interval B occupies the depth range 3.02-7.1 mbsf. Radiolaria in Interval B are locally rare to abundant and well preserved, and assemblages range in age from pure early Eocene to early Eocene admixed with late Neogene taxa. Radiolaria distribution Interval C occupies the depth range 7.1-36.99 mbsf and is characterized by sediments either barren of microfossils or containing extremely rare early Eocene specimens.

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Radiolaria distribution Interval D occupies the depth range 36.99-38.7 mbsf (base of the recovered sedimentary section), where early Eocene Radiolaria are present in rare to common frequencies, but opal-A to opal-CT recrystallization has degraded the preservation state. The late Neogene assemblage of Radiolaria distribution Interval B is dated at 1.55-2.0 Ma, based on occurrences of Eucyrtidium matuyamai, Lamprocyclas heteroporos, and Theocorythium trachelium trachelium.

The early Eocene assemblage of Radiolaria distribution Intervals B and D is somewhat problematically assigned to the Buryella clinata Zone.

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Catalogue records · 1

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Inferred from text
Geology 72%
Provenance · 1 source records, 8 field assertions
SourceKeyLast seenRaw
PANGAEAoai:pangaea.de:doi:10.1594/PANGAEA.77763412 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · PANGAEAconnector:pangaea@1.0.0
concepts[field].anzsrc:group:3705enrichment · PANGAEAtaxonomy-embedding@1.1.0title+keywords+description (72%)
concepts[field].local:field:earth-environmentalmapping · PANGAEAconnector:pangaea@1.0.0
descriptionsource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/description
licensesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/rights
publication_datesource · PANGAEAconnector:pangaea@1.0.0
spatialsource · PANGAEAconnector:pangaea@1.0.0
titlesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/title