Gomila, Rodrigo and Fondriest, Michele and Jensen, Erik and Spagnuolo, Elena and Masoch, Simone and Mitchell, Thomas and Magnarini, Giulia and Bistacchi, Andrea and Mittempergher, Silvia and Faulkner, Daniel and Cembrano, José and Di Toro, Giulio
(2023)
Frictional Melting in Hydrothermal Fluid-Rich Faults:
Field and Experimental Evidence From the Bolfín Fault
Zone (Chile).
[Data Collection]
Collection description
Tectonic pseudotachylytes are thought to be unique to certain water-deficient seismogenic environments and their presence is considered to be rare in the geological record. Here, we present field and experimental evidence that frictional melting can occur in hydrothermal fluid-rich faults hosted in
the continental crust. Pseudotachylytes were found in the >40 km-long Bolfín Fault Zone of the Atacama Fault System, within two ca. 1 m-thick (ultra)cataclastic strands hosted in a damage-zone made of chlorite-epidote-rich hydrothermally altered tonalite. This alteration state indicates that hydrothermal fluids were active during the fault development. Pseudotachylytes, characterized by presenting amygdales,
cut and are cut by chlorite-, epidote- and calcite-bearing veins. In turn, crosscutting relationship with the hydrothermal veins indicates pseudotachylytes were formed during this period of fluid activity. Rotary shear experiments conducted on bare surfaces of hydrothermally altered rocks at seismic slip velocities
(3 m s−1) resulted in the production of vesiculated pseudotachylytes both at dry and water-pressurized conditions, with melt lubrication as the primary mechanism for fault dynamic weakening. The presented evidence challenges the common hypothesis that pseudotachylytes are limited to fluid-deficient environments, and gives insights into the ancient seismic activity of the system. Both field observations and experimental evidence, indicate that pseudotachylytes may easily be produced in hydrothermal
environments, and could be a common co-seismic fault product. Consequently, melt lubrication could be considered one of the most efficient seismic dynamic weakening mechanisms in crystalline basement rocks of the continental crust.
DOI: |
10.25430/researchdata.cab.unipd.it.00000887 |
Keywords: |
Bolfín Fault Zone, pseudotachylytes, Atacama Fault System, Rotary shear experiments, vesiculated pseudotachylytes, hydrothermal fluid-rich environment |
Subjects: |
Physical:Sciences and Engineering > Earth System Science: Physical geography, geology, geophysics, atmospheric sciences, oceanography, climatology, cryology, ecology, global environmental change, biogeochemical cycles, natural resources management > Mineralogy, petrology, igneous petrology, metamorphic petrology Physical:Sciences and Engineering > Earth System Science: Physical geography, geology, geophysics, atmospheric sciences, oceanography, climatology, cryology, ecology, global environmental change, biogeochemical cycles, natural resources management > Geology, tectonics, volcanology Physical:Sciences and Engineering > Earth System Science: Physical geography, geology, geophysics, atmospheric sciences, oceanography, climatology, cryology, ecology, global environmental change, biogeochemical cycles, natural resources management > Physics of earth's interior, seismology, volcanology |
Department: |
Departments > Dipartimento di Geoscienze |
Depositing User: |
Rodrigo Alfonso Gomila Olmos de aguilera
|
Date Deposited: |
16 May 2023 14:03 |
Last Modified: |
16 May 2023 14:03 |
Creators/Authors: |
Creators | Email | ORCID |
---|
Gomila, Rodrigo | r.gomilaolmosdeaguilera@unipd.it | orcid.org/0000-0001-5807-2769 | Fondriest, Michele | UNSPECIFIED | orcid.org/0000-0002-1294-0820 | Jensen, Erik | UNSPECIFIED | orcid.org/0000-0003-0790-6270 | Spagnuolo, Elena | UNSPECIFIED | orcid.org/0000-0002-1377-5812 | Masoch, Simone | UNSPECIFIED | orcid.org/0000-0001-9976-9423 | Mitchell, Thomas | UNSPECIFIED | orcid.org/0000-0003-0809-1528 | Magnarini, Giulia | UNSPECIFIED | orcid.org/0000-0002-5200-261X | Bistacchi, Andrea | UNSPECIFIED | orcid.org/0000-0002-0139-2785 | Mittempergher, Silvia | UNSPECIFIED | orcid.org/0000-0002-7278-1200 | Faulkner, Daniel | UNSPECIFIED | orcid.org/0000-0002-6750-3775 | Cembrano, José | UNSPECIFIED | orcid.org/0000-0003-4247-8259 | Di Toro, Giulio | UNSPECIFIED | orcid.org/0000-0002-6618-3474 |
|
Type of data: |
Text |
Research funder: |
Marie Skłodowska-Curie Actions, European Research Council, Fondo Nacional de Desarrollo Científico y Tecnológico |
Research project title: |
FRICTION, NOFEAR |
Grant number: |
896346 |
Collection period: |
|
Resource language: |
English |
Metadata language: |
English |
Publisher: |
Research Data Unipd |
Related publications: |
|
Date: |
16 May 2023 |
Copyright holders: |
The Author |
URI: |
https://researchdata.cab.unipd.it/id/eprint/887 |
Creators/Authors: |
Creators | Email | ORCID |
---|
Gomila, Rodrigo | r.gomilaolmosdeaguilera@unipd.it | orcid.org/0000-0001-5807-2769 | Fondriest, Michele | UNSPECIFIED | orcid.org/0000-0002-1294-0820 | Jensen, Erik | UNSPECIFIED | orcid.org/0000-0003-0790-6270 | Spagnuolo, Elena | UNSPECIFIED | orcid.org/0000-0002-1377-5812 | Masoch, Simone | UNSPECIFIED | orcid.org/0000-0001-9976-9423 | Mitchell, Thomas | UNSPECIFIED | orcid.org/0000-0003-0809-1528 | Magnarini, Giulia | UNSPECIFIED | orcid.org/0000-0002-5200-261X | Bistacchi, Andrea | UNSPECIFIED | orcid.org/0000-0002-0139-2785 | Mittempergher, Silvia | UNSPECIFIED | orcid.org/0000-0002-7278-1200 | Faulkner, Daniel | UNSPECIFIED | orcid.org/0000-0002-6750-3775 | Cembrano, José | UNSPECIFIED | orcid.org/0000-0003-4247-8259 | Di Toro, Giulio | UNSPECIFIED | orcid.org/0000-0002-6618-3474 |
|
Type of data: |
Text |
Research funder: |
Marie Skłodowska-Curie Actions, European Research Council, Fondo Nacional de Desarrollo Científico y Tecnológico |
Research project title: |
FRICTION, NOFEAR |
Grant number: |
896346 |
Collection period: |
|
Resource language: |
English |
Metadata language: |
English |
Publisher: |
Research Data Unipd |
Related publications: |
|
Date: |
16 May 2023 |
Copyright holders: |
The Author |
Last Modified: |
16 May 2023 14:03 |
|
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