Identification

Title

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

Abstract

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WDS-EPMA results for all tephra layers studied in the DeepCHALLA sediment record; and (5) secondary standard data; (6) unpublished Diatom ?18O (‰ VSMOW), Bulk organic ?13C (‰), %C and Diatom d13C (‰) measurements for the full length of the core (given on a composite depth scale).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 Stable isotope data (produced by Barker and Leng) remains unpublished at the time of upload.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.

Resource type

nonGeographicDataset

Resource locator

https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item181873

name: Data

function: download

Unique resource identifier

code

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

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

originating controlled vocabulary

title

reference date

date type

publication

effective date

2008-06-01

Keyword set

keyword value

Palaeoclimatology

NGDC Deposited Data

Potassium argon dating

Volcanic ejecta

Quaternary

Age determination methods

originating controlled vocabulary

title

reference date

date type

revision

effective date

2022

Keyword set

keyword value

Keyword set

keyword value

NERC_DDC

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

2017-04-01

End position

2022-09-26

Dataset reference date

date type

creation

effective date

2023-08-07

Frequency of update

notApplicable

Quality and validity

Lineage

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).

Conformity

Conformity report

specification

title

reference date

date type

publication

effective date

2011

degree

false

explanation

See the referenced specification

Conformity report

specification

title

reference date

date type

publication

effective date

2010-12-08

degree

false

explanation

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

Data format

name of format

MS Excel

version of format

Constraints related to access and use

Constraint set

Limitations on public access

Constraint set

Limitations on public access

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.

Responsible organisations

Responsible party

contact position

Professor of Geography

organisation name

University of Cambridge

full postal address

Department of Geography , Downing Place

Cambridge

CB2 3EN

email address

not available

responsible party role

originator

Responsible party

organisation name

British Geological Survey

email address

not available

responsible party role

distributor

Responsible party

organisation name

British Geological Survey

email address

not available

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

organisation name

British Geological Survey

full postal address

Environmental Science Centre,Keyworth

NOTTINGHAM

NG12 5GG

United Kingdom

telephone number

+44 115 936 3100

email address

enquiries@bgs.ac.uk

responsible party role

pointOfContact

Metadata date

2024-04-18

Metadata language