Geophysical Borehole logging at Santa Gracia, Chile

DOI

The DFG funded DeepEarthshape project within the SPP1803 EarthShape (second phase) combines several geoscientific methods and approaches to study the weathering zone in detail in dependence of climate conditions. Projects of the first phase have shown that the weathering zone is much deeper than expected, so that the weathering front was never encountered in the excavated soil pits. At depth of 1 – 2 m appreciable amounts of microbial biomass and DNA counts were encountered. It was further found that bacteria and archaea colonizing rock surfaces are close relatives to those from deeper soil zones. Because we do not know a) the depth of weathering; b) the process advancing it; c) whether this advance is driven by water, gases, and/or biological activity and concentrated along faults; d) whether this zone presents a habitat and interacts with the surface biosphere, we have designed a drilling campaign at all four study sites for joint geochemical, biogeochemical and microbiological exploration and a geophysical campaign for imaging the depth and physical properties of the critical zone. The principle hypotheses of the DeepEarthshape projects are: 1) The advance of the weathering front at depth is a recent process that is linked to climate and coupled with erosion at the surface through a biogeochemical feedback 2) Microbial activity in the deep regolith that advances weathering is fuelled by young organic matter. The four study sites are distributed along the coast of Chile to have a similar geological setting at one hand but different climatic conditions.

Here we present the logging data of the first geophysical borehole survey which took place at Santa Gracia, 40 km NE of La Serena (Coquimbo Region, Chile). The data were acquired on the 2nd of April 2019 between . The borehole logging was conducted by COMPROBE. The vertical borehole reached down to 87.2 m depth and had a diameter (PQ) of 83.5 mm.

The Acoustic Televiewer data are freely accessible now in .dlis and PDF formats. The original data files are embargoed until the 30 June 2022.

Identifier
DOI https://doi.org/10.5880/GFZ.2.7.2020.001
Metadata Access http://doidb.wdc-terra.org/oaip/oai?verb=GetRecord&metadataPrefix=oai_datacite&identifier=oai:doidb.wdc-terra.org:6975
Provenance
Creator Weckmann, Ute ORCID logo; Bauer, Klaus ORCID logo; Krawczyk, Charlotte ORCID logo; Kück, Jochem ORCID logo; Übernickel, Kirstin ORCID logo; von Blanckenburg, Friedhelm ORCID logo
Publisher GFZ Data Services
Contributor Weckmann, Ute; Bauer, Klaus; Krawczyk, Charlotte; Kück, Jochem; Übernickel, Kirstin; von Blanckenburg, Friedhelm; Araya Vargas, Jaime
Publication Year 2020
Funding Reference Deutsche Forschungsgemeinschaft http://doi.org/10.13039/501100001659 Crossref Funder ID WE3829/13-1 Gides - SPP1803
Rights CC BY 4.0; http://creativecommons.org/licenses/by/4.0/
OpenAccess true
Contact Weckmann, Ute (GFZ German Research Centre for Geosciences, Potsdam, Germany)
Representation
Resource Type Dataset
Discipline Geosciences
Temporal Coverage Begin 2022-06-30T00:00:00Z
Temporal Coverage End 2024-06-02T00:00:00Z