Publication Date:
2024-06-03
Description:
Abstract
Description:
All datasets provided in the operational dataset (Heubeck et al., 2024) of the ICDP project BASE (ICDP 5069) consist of metadata, data and/or images. Here, a summary of explanations of the tables, data and images exported from the database of the project (mDIS BASE) are given and are complemented by additional information on data from measurements done in the laboratory prior to the sampling party. Finally, the sampling data from the first two sampling parties are added. Some basic definitions of identifiers used in ICDP, depths corrections and measurements are also introduced.
The BASE (Barberton Archean Surface Environments) scientific drilling project focused on recovering unweathered continuous core through strata of the Paleoarchean Moodies Group (ca. 3.2 Ga), central Barberton Greenstone Belt (BGB), South Africa. They comprise some of the oldest well-preserved sedimentary strata on Earth, deposited within only a few million years in alluvial, fluvial, coastal-deltaic, tidal, and prodeltaic settings; they represent a very-high-resolution record of Paleoarchean surface conditions and processes. Moodies Group strata consist of polymict conglomerates, widespread quartzose, lithic and arkosic sandstones, siltstones, shales, and rare BIFs and jaspilites, interbedded with tuffs and several thin lavas. This report describes operations from preparations to the sampling workshop and complements the related scientific report.
Eight inclined boreholes between 280 and 495 m length, drilled during November 2021 through July 2022, obtained a total of 2903 m of curated core of variable quality through steeply to subvertically dipping, in part overturned stratigraphic sections. All drilling objectives were reached. Boreholes encountered a variety of conglomerates, diverse and abundant, mostly tuffaceous sandstones, rhythmically laminated shale-siltstone and banded-iron formations, and several horizons of early-diagenetic sulfate concretions. Oxidative weathering reached far deeper than expected; fracturing was more intense, and BIFs and jaspilites were thicker than anticipated. Two km-long mine adits and a water tunnel, traversing four thick stratigraphic sections within the upper Moodies Group in the central BGB, were also sampled. All boreholes were logged by geophysical instruments. Core was processed (oriented, slabbed, photographed, described, and archived) in a large, publicly accessible hall in downtown Barberton. An exhibition provided background explanations for visitors and related the drilling objectives to the recently established Barberton-Makhonjwa Mountains World Heritage Site. A substantial education, outreach and publicity program addressed the information needs of the local population and of local and regional stakeholders.
Keywords:
Africa
;
South Africa
;
Barberton
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Early Life Ecology
;
Greenstone Belt
;
Moodies
;
ocean and atmosphere
;
oxygen
;
ICDP
;
International Continental Scientific Drilling Programme
;
EARTH SCIENCE 〉 PALEOCLIMATE 〉 LAND RECORDS 〉 BOREHOLES
;
EARTH SCIENCE 〉 SOLID EARTH 〉 GEOCHEMISTRY 〉 GEOCHEMICAL PROPERTIES
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Precambrian 〉 Archean
Type:
Dataset
,
Dataset
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