PANGAEA_996239
Coccolith abundance, assemblage structure, and sedimentological properties along core DA12‑11/2‑ST1‑GC01
Ukpabi, Ndubuisi; Seidenkrantz, Marit-Solveig
Coccolith abundance, assemblage structure, and sedimentological properties along core DA12‑11/2‑ST1‑GC01
2026-07-31
PANGAEA
Dataset
https://doi.pangaea.de/10.1594/PANGAEA.996239
Investigator
Ndubuisi
Ukpabi
edgar2005ng@gmail.com
Earth Science
DEPTH, sediment/rock
Depth, top/min
Depth, bottom/max
Color description
Sediment type
Coccoliths, total
Fields
Radius
Subsample, dry mass
Sample, dry mass
Coccoliths
Coccoliths
Calcidiscus leptoporus
Calcidiscus leptoporus
Coccolithus pelagicus
Coccolithus pelagicus
Helicosphaera carteri
Helicosphaera carteri
Gephyrocapsa spp.
Gephyrocapsa spp.
Emiliania huxleyi
Emiliania huxleyi
Syracosphaera pulchra
Syracosphaera pulchra
Umbilicosphaera spp.
Umbilicosphaera spp.
Pontosphaera discopora
Pontosphaera discopora
Pontosphaera japonica
Pontosphaera japonica
Braarudosphaera bigelowii
Braarudosphaera bigelowii
geoscientificInformation
absolute abundance
assemblage dynamics
Atlantic Water
coccolith assemblages
DA12-11/2-GC01
Dana12-11
G1
Gravity corer
hydrographic interpretation
Micropaleontology
Paleoceanography
quantitative microscopy
sediment core DA12 11/2 ST1 GC01
SEM
taxon ecology
Counting, coccoliths
Dana (1981)
2025-09-12
2025-09-12
Complete
61.60893
61.60893
-20.70273
-20.70273
0.005 m (DEPTH, sediment/rock)
4.18 m (DEPTH, sediment/rock)
unrestricted
CC-BY-4.0: Creative Commons Attribution 4.0 International
English
PANGAEA
Data Publisher for Earth & Environmental Science
https://www.pangaea.de/
Data Center Contact
Michael
Diepenbroek
info@pangaea.de
Leobener Str.
Bremen
Bremen
28359
Germany
online
2238 data points
text/tab-separated-values
Ukpabi, Ndubuisi; Seidenkrantz, Marit-Solveig (in press): Holocene hydrography of the Iceland Basin from coccolith ecological contrasts: A multi‑axis index for salinity and stratification. Marine Micropaleontology
This dataset presents a high resolution sequence of coccolithophore assemblages and absolute abundances from 0–419 cm in core DA12 11/2 ST1 GC01, capturing fine scale ecological variability across predominantly dark grey calcareous ooze interspersed with discrete ash layers. Coccolith counts range from extremely low values in ash dominated horizons to >900 specimens in more stable intervals, with absolute abundances varying by over two orders of magnitude. Assemblages are consistently dominated by Coccolithus pelagicus, Gephyrocapsa spp., and Emiliania huxleyi, whose shifting proportions delineate transitions between cool, stratified, and nutrient rich surface water states. Upper Holocene samples show strong C. pelagicus dominance with intermittent increases in E. huxleyi, reflecting oscillations between Atlantic influenced and Polar modified waters. Mid core intervals exhibit pronounced rises in Gephyrocapsa spp., marking episodes of enhanced small form productivity and possible changes in mixing intensity. Occasional occurrences of Helicosphaera carteri, Syracosphaera pulchra, Umbilicosphaera spp., and rare Pontosphaera taxa indicate intermittent incursions of warmer or more oligotrophic conditions. Ash layers consistently show reduced counts, simplified assemblages, and strong dominance by a single taxon, reflecting ecological suppression during volcanic deposition. Across the full sequence, the interplay between dominant and accessory taxa reveals coherent patterns of hydrographic restructuring, including shifts in thermal regimes, salinity gradients, nutrient supply, and stratification intensity. These assemblage variations provide a detailed ecological fingerprint of Holocene surface water dynamics in the Iceland Basin and form the basis for subsequent derivation of ecological contrasts and hydrographic indices. ** For all details see the full metadata description at "https://doi.pangaea.de/10.1594/PANGAEA.996239"!
http://www.marinespecies.org/aphia.php?p=taxdetails&id=115104
Emiliania huxleyi
http://www.marinespecies.org/aphia.php?p=taxdetails&id=235823
Gephyrocapsa spp.
http://www.marinespecies.org/aphia.php?p=taxdetails&id=235857
Umbilicosphaera spp.
http://www.marinespecies.org/aphia.php?p=taxdetails&id=235922
Braarudosphaera bigelowii
http://www.marinespecies.org/aphia.php?p=taxdetails&id=235923
Calcidiscus leptoporus
http://www.marinespecies.org/aphia.php?p=taxdetails&id=235979
Syracosphaera pulchra
http://www.marinespecies.org/aphia.php?p=taxdetails&id=615435
Helicosphaera carteri
https://dana.dtu.dk/en/historien-om-dana
Dana (1981)
PANGAEA_996263
DIF
9.4
2026-07-31
2026-07-31