Lake Chala (Kenya/Tanzania) chronology and isotope data, 0 - >250 kyr BP (DeepCHALLA project) (NERC Grant NE/P011969/1)

This dataset presents tephra layers, Ar-dates, age-model & stable isotope data from the >250 kyr-long Lake Chala sediment record, Kenya/Tanzania. The file is split into six tables: (1) metadata on the 30 tephra layers (29 visible tephra layers, one cryptotephra) studied to date, including sample and core codes, summary characteristics and ages; (2) summary of Ar-dating results on ten of the Lake Chala tephra layers; (3) the DCH_TephraAge Bayesian age model, which combines tephra, 210Pb and 14C age-estimates for the length of the core; (4) Raw single-grain WDS-EPMA results for all tephra layers studied in the DeepCHALLA sediment record; and (5) secondary standard data; (6) unpublished Diatom ?18O (‰ VSMOW), Bulk organic ?13C (‰), %C and Diatom d13C (‰) measurements for the full length of the core (given on a composite depth scale). These chronological data (Tables 1-5) are central to the reconstruction of palaeoclimate from a multi-proxy analyses of the Lake Chala sediment sequence and are included in publications by Baxter et al. (2023) and Martin-Jones et al. (2020, in review), for which references are given in the appropriate files. Stable isotope data (produced by Barker and Leng) remains unpublished at the time of upload. The data was generated by Catherine Martin-Jones, Christine Lane, Maarten Blaauw, Darren Mark, Melanie Leng and Phil Barker between 2017-2022. Much of the tephra data is published and references are provided.

Date (Creation): 2023-08-07

Identifier: http://data.bgs.ac.uk/id/dataHolding/13608096

Originator

University of Cambridge - Christine Lane ( Professor of Geography )

Department of Geography , Downing Place , Cambridge , CB2 3EN ,

Distributor

British Geological Survey - Enquiries

Point of contact

British Geological Survey - Enquiries

Maintenance and update frequency: notApplicable notApplicable

GEMET - INSPIRE themes, version 1.0

Geology

BGS Thesaurus of Geosciences

Palaeoclimatology
NGDC Deposited Data
Potassium argon dating
Volcanic ejecta
Quaternary
Age determination methods

dataCentre

NGDC Deposited Data

Keywords

NERC_DDC

Access constraints: otherRestrictions 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: otherRestrictions 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: There are no restrictions on the use that may be made of the dataset, although an appropriate copyright acknowledgement must be made when any part of the dataset is reproduced. Either no third party data / information is contained in the dataset or BGS has secured written permission from the owner of any third party data / information contained in the dataset to make the dataset freely available without any use constraints - inclusion of any third party data / information will affect the copyright acknowledgement that needs to be made.

Metadata language: EnglishEnglish

Topic category

Geoscientific information

Begin date: 2017-04-01

End date: 2022-09-26

Reference System Information

No information provided.

Distribution format

MS Excel ()

Distributor

British Geological Survey - Enquiries

OnLine resource: Data

Hierarchy level: nonGeographicDataset Non geographic dataset

Other: non geographic dataset

Conformance result

Date (Publication): 2011

Explanation: See the referenced specification

Pass: No

Conformance result

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: Tephra were detected / described visually and compositional data is single-glass shard WDS-EPMA, run at the University of Cambridge. Ar-dating was carried out on manually picked K-feldspars and samples irradiated in the CLICIT facility at Oregon State University using the Alder Creek sanidine as neutron fluence monitor. 40Ar/39Ar analyses then conducted at the SUERC National Environmental Isotope Facility, following standard protocols. Age-modelling in BACON (Blaauw and Christen, 2011) combines 210Pb & 14C dates from the 25 kyr-long CHALLACEA record (Blaauw et al., 2011) with in-situ Ar-ages and the age of the YTT tephra (Mark et al., 2017). Diatom O and C isotopes measured by mass spectrometry on purified diatom samples at the British Geological Survey (BGS, Keyworth) and Lancaster University, respectively. TOC and C isotopes measured using IRMS at BGS (Keyworth).