Late Eocene microspherule count and foraminifera multispecies oxygen and carbon stable isotope data from DSDP Site 94

Twenty-six 10 cm3 samples from DSDP (Deep Sea Drilling Project) Site 94, Core 15, sections 3 and 4 were examined at 10 cm-intervals (417.84-415.01 meters below seafloor [mbsf]). The sedimentary material was soaked in distilled water and washed under running water through a 63 µm sieve and oven dried at <40 degrees C. Samples were then re-washed and dried using the same method. Foraminifera are abundant and recystallised. Calcite precipitation is observed on microspherules in some samples. For each sample, a total of three foraminiferal species that correspond to different ecological habitats were selected for isotope analysis. Specimens of Pseudohastigerina micra and P. naguewichiensis were selected from the 125-250 µm size fraction and Turborotalia cocoaensis, and Cibicidoides eocaenus were selected from the >250 µm size fraction. Specimens that had infilling or showed heavy calcification were avoided. All foraminifera were ultrasonicated for 2 seconds prior to isotopic analyses. To track the number of impact microspherules across the sampled interval, we performed our own microspherules count from the >125 micron size fraction. Microtektites have not been distinguished from microkrystites in this study and thus all recovered spherules should be considered under the broader category of microspherules (both microtektites and crystalline-bearing microkrystites). We recovered a total of 4999 microspherules from the 26 samples. Microspherules are usually <1 mm in size, and occur primarily spherical, although ellipsoid, teardrop and dumbbell forms and fragments have also been found. In most samples the microspherules count is low <50 microspherules. We found a high abundance (>50 microspherules/10 cm3) between samples 15R/3/135-137 cm and 15R/3/89-91 cm (416.36 to 415.90 mbsf). Our peak concentration of microspherules at 15R/3/109-111 cm (416.10 mbsf), where 3395 microspherules were recovered, coincides with the younger of the two late Eocene impacts i.e., the North America microtektite horizon associated with the Chesapeake Bay impact.

Date (Creation): 2024-10-13

Citation identifier: http://data.bgs.ac.uk/id/dataHolding/13608286

Point of contact

Organisation name	Individual name	Electronic mail address	Role
University College London	Professor Bridget Wade	not available	Originator
University College London	Natalie Cheng	not available	Originator
British Geological Survey	Enquiries	not available	Distributor
British Geological Survey	Enquiries	not available	Point of contact

Maintenance and update frequency: notApplicable

GEMET - INSPIRE themes, version 1.0

Geology

BGS Thesaurus of Geosciences

Tektites
NGDC Deposited Data
Eocene
Foraminifera
Stable isotopes

dataCentre

NGDC Deposited Data

Keywords

NERC_DDC

Access constraints: Other restrictions

Other constraints: licenceOGL

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Use constraints: Other restrictions

Other constraints: The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Language: English

Topic category

Geoscientific information

Begin date: 2018-01-25

End date: 2024-04-03

Reference System Information

No information provided.

Distribution format

Name	Version
MS Excel

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	not available	Distributor

OnLine resource

Protocol	Linkage	Name
	https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item186339	Data

OnLine resource

Protocol	Linkage	Name
	https://doi.org/10.5285/a0b6a773-1d18-4ced-a57e-06f8d67428b9	Digital Object Identifier (DOI)

Hierarchy level: Non geographic dataset

Other: non geographic dataset

Conformance result

Title: INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology

Date (Publication): 2011

Explanation: See the referenced specification

Pass: No

Conformance result

Title: Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

Date (Publication): 2010-12-08

Explanation: See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Pass: No

Statement: Foraminifera were analysed at the Bloomsbury Environmental Isotope Facility (BEIF) at University College London on a Thermo DeltaPLUS XP continuous-flow Gas-ratio mass spectrometer attached to a Thermo Gas Bench II device. Precision of all internal (BDH) and external standards (NBS-19) is ±0.06‰ for δ13C and ±0.10‰ for δ18O for the planktonic foraminiferal samples, and ±0.02‰ for δ13C and ±0.06‰ for δ18O for the benthic foraminiferal samples. All isotope values are normalised to NBS-19 and reported in per mil in the δ notation relative to the Vienna Pee Dee Belemnite (VPDB).