Miocene siliceous microfossil occurence of sediment core CRP-1 (Table 3) ...

Lower Miocene diatoms and other siliceous microfossils in the Cape Robcrts Project drillcore (CRP-l), Roberts Ridge, western McMurdo Sound, are documented. Diatom biostratigraphy, along with 87Sr/86Sr ratios from mollusk shells and 40Ar/39Ar data from volcanic materials, constrain the interpretation...

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Bibliographic Details
Main Authors: Harwood, David M, Bohaty, Steven M, Scherer, Reed P
Format: Dataset
Language:English
Published: PANGAEA 1998
Subjects:
DEPTH, sediment/rock
Depth, top/min
Depth, bottom/max
Lithologic unit/sequence
Siliceous microfossils
Preservation
Arachnoidiscus sp.
Asteromphalus symmetricus
Cavitatus jouseanus
Cavitatus miocenica
Cavitatus rectus
Cymatosira biharensis
Dactyliosolen antarcticus
Fragilariopsis sp.
Diatoms indeterminata
Hercotheca inermis
Rhabdonema sp.
Rhizosolenia sp.
Stephanopyxis spinosissima
Stephanopyxis sp.
Tigeria spp.
Thalassiosira praefraga
Thalassiosira nansenii
Trinacria racovitzae
Corbisema triacantha
Septamesocena pappii
Core wireline system
Counting >25 µm fraction
Estimated
Abundance estimate
CRP-1
Sampling/drilling ice
Cape Roberts Project CRP
Antarc*
antarcticus
McMurdo Sound
Online Access:https://dx.doi.org/10.1594/pangaea.433491
https://doi.pangaea.de/10.1594/PANGAEA.433491
Description
Summary:Lower Miocene diatoms and other siliceous microfossils in the Cape Robcrts Project drillcore (CRP-l), Roberts Ridge, western McMurdo Sound, are documented. Diatom biostratigraphy, along with 87Sr/86Sr ratios from mollusk shells and 40Ar/39Ar data from volcanic materials, constrain the interpretation of the magnetic polarity stratigraphy and allows construction of an age model for CRP-1. Together, these records indicate an age span from to ~21.5 Ma at 147.69 mbsf (the bottom of the hole) to ~17.5 Ma at 43.15 mbsf (top of the lower Miocene interval). Important diatom datums identified in this drillcore are the FAD and LAD of Thalassiosira praefraga and the LAD of Cavitatus rectus. Variation in diatom abundance and assemblage composition through the lower Miocene reflects changes in depositional environment. There are intervals of repeated ice cover (floating or grounded) in the lower Miocene section of CRP-1, where diatom production was limited, and intervals where diatoms were growing in open, although at ... : N = none, R= rare, F = few, X = present ...

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