Carbon dioxide flux and isotopic composition from sedimentary rock weathering, Draix-Bleone Critical Zone Observatory, France

The measurements and data were obtained to study the release of carbon dioxide during the chemical weathering of sedimentary rocks, and how these CO2 fluxes were related to environmental parameters (temperature, hydrology). Weathering of sedimentary rocks can result in CO2 release from the oxidation of rock organic carbon oxidation, but also due to the oxidation of sulfide minerals, production of sulfuric acid and subsequent release of CO2 from carbonate minerals. The rock-derived carbon sources are understudied, and form an important part of the geological carbon cycle. The CO2 flux measurements were made on 5 rock chambers (H4, H6, H7, H8 and H13) installed in the Draix-Bleone Critical Zone Observatory, France, on outcrops of Jurassic marls. Measurements and data were collected from December 2016 to May 2019. Regular visits to the site (~4 per year) returned data on total CO2 flux (Total-CO2-flux.csv). This was explored as a function of temperature and ambient hydroclimate (precipitation). The datasets include the total CO2 flux measured at each visit to a chamber, and measurements of the internal chamber temperature. To determine the source of CO2 measured in the chambers, we trapped the CO2 using zeolite sieves and recovered it in the laboratory. The radiocarbon activity (reported as fraction modern, F14C) and its stable isotope composition (d13C) were measured from CO2 collected from chambers H4 and H6 over the sampling period (Radiocarbon-data.csv). These were used in a mixing analysis to partition the source of CO2 using a mixing model approach (Partitioned-CO2-fluxes.csv) as explained in full in the published paper Soulet et al., 2021, Nature Geoscience. We also measured the geochemical characteristics of the bedrocks being measured (rock-geochemical-composition.csv), including the organic carbon concentration, inorganic carbon concentration and their isotopic composition. Finally, we measured environmental variables of interest - the chamber temperature and the air temperature at the Draix-Bleone observatory (chamber-temperature.csv and Air-temperature-at-laval-le-plateau-weather-station.csv, respectively). This research was funded by a European Research Council Starting Grant to Robert Hilton (ROC-CO2 project, grant 678779) and radiocarbon and stable isotope measurements were funded by the Natural Environment Research Council (NERC), UK, (NERC Environmental Isotope Facility NEIF Radiocarbon Allocation 2074.1017) to Guillaume Soulet, Robert Hilton and Mark Garnett. Full details of data analysis and interpretation can be found in Soulet et al., 2021, Temperature control on CO2 emissions from the weathering of sedimentary rocks, Nature Geoscience

Date (Creation): 2021-06-08

Citation identifier: http://data.bgs.ac.uk/id/dataHolding/13607769

Point of contact

Organisation name	Individual name	Electronic mail address	Role
University of Durham	Robert Hilton	not available	Originator
IFREMER	Guillaume Soulet	not available	Originator
IRSTEA	Sebastian Klotz	not available	Originator
NERC Radiocarbon Facility	Mark Garnett	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

Carbon dioxide
Carbon isotopes
Carbonates
Jurassic
Marls
NGDC Deposited Data
Sedimentary rocks
Chemical weathering
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

Geographic identifier: ALPES-DE-HAUTE-PROVENCE [id=240700]
British Geological Survey Gazetteer: Geographical hierarchy from Geosaurus 1979 creation

Geographic identifier: FR
ISO 3166_1 alpha-2 2009 revision

Geographic identifier: FRA
ISO 3166_1 alpha-3 2009 revision

Geographic identifier: FRANCE [id=210000]
British Geological Survey Gazetteer: Geographical hierarchy from Geosaurus 1979 creation

Begin date: 2016-12-14

End date: 2019-05-09

Unique resource identifier: WGS 84 (EPSG::4326)

Distribution format

Name	Version
csv

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#item166685	Data

OnLine resource

Protocol	Linkage	Name
	https://doi.org/10.5285/efc082aa-5c2b-4afb-aec8-344aebaea653	Digital Object Identifier (DOI)

Hierarchy level: Dataset

Other: 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: Rock chambers to measure CO2 fluxes were installed following the methods of Soulet et al., (2018), Biogeosciences, whereby each chamber is drilled directly into the rock with a rock drill. Five chambers were installed in barren marls in the Laval river (N44.1406, E06.3628). CO2 fluxes were measured using an infra-red infra-red gas analyser, using a molecular sieve sampling system to trap CO2. The isotopic composition of CO2 was measured by IRMS and AMS. Rock samples were analysed by EA-IRMS. End member mixing analysis was returned to partition CO2 sources between carbonate and rock organic carbon. Temperature was measured using a HMP45C temperature and relative humidity probe (Campbell Scientific Inc.).