Date ( Creation )

2021-06-25

Identifier

http://data.bgs.ac.uk/id/dataHolding/13607774

Maintenance and update frequency

notApplicable notApplicable

GEMET - INSPIRE themes

• Geology

BGS Thesaurus of Geosciences

• Thorium , Samarium , Helium , Weathering , Geochronology , Uranium , Porphyry copper deposits

Keywords

• NERC_DDC

Access constraints

otherRestrictions Other restrictions

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

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

Spatial representation type

textTable Text, table

Metadata language

English English

Topic category

• Geoscientific information

Geographic identifier

ANDES [id=842000]

 

Date ( Creation )

1979

Supplemental Information

Royal Society Research Grant RG140683

Distribution format

• MS Excel ()

OnLine resource

Data  

Hierarchy level

dataset Dataset

Other

dataset

Statement

(U-Th-Sm)/He dating was done at Caltech, using the single aliquot method (Farley, 2002; House et al., 2000). Hematite fragments were loaded into Pt tubes and degassed by incremental heating with a Nd-YAG laser to >1000⁰ C. He extraction conducted under high pO2 (100 torr), buffering the hematite-magnetite transition to >1200° C (Hofmann et al., 2020). Isotope-dilution measurements of 4He were made with an enriched 3He spike, using a Pfeiffer Vacuum quadrupole mass spectrometer. U, Th and Sm were measured on the same aliquots using an Agilent 8800 triple-quadrupole ICP-MS (e.g. Hofmann et al., 2017). (U-Th-Sm)/He ages were calculated according to Farley (2002). Since aliquots were taken from structures much larger than the typical alpha-particle stopping distance in hematite of 13-16 µm (Ketcham et al., 2011), no correction for alpha-ejection or -implantation was applied.

gmd:MD_Metadata

File identifier

c5e58fbf-dc07-1bbf-e054-002128a47908   XML

Metadata language

English English

Hierarchy level

dataset Dataset

Date stamp

2021-12-08

Metadata standard version

2.3

Dataset URI

http://data.bgs.ac.uk/id/dataHolding/13607774