Fault mirrors in the process zone of a seismogenic fault (Karawanks, Eastern Alps)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985891%3A_____%2F25%3A00636906" target="_blank" >RIV/67985891:_____/25:00636906 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.17738/ajes.2025.0006" target="_blank" >https://doi.org/10.17738/ajes.2025.0006</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.17738/ajes.2025.0006" target="_blank" >10.17738/ajes.2025.0006</a>

Result language

angličtina

Original language name

Fault mirrors in the process zone of a seismogenic fault (Karawanks, Eastern Alps)

Original language description

Square centimetres sized polished fault surfaces are exposed in the vicinity of a seismic fault in the Obir Caves (Northern Karawanks, Carinthia, Austria). Microtectonic studies reveal that contrary to published natural and experimental fault mirrors, these small-scale faults record almost no displacement. Based on our findings, we propose a new process, in which during the passage of seismic waves, small shaking movements along the slip surfaces with hardly any offset caused the development of polished slickensides. The Obir Caves in the Hochobir massif are located just north of the seismogenic ESE striking, dextral Periadriatic Fault System, which forms the boundary between the Eastern and the Southern Alps. The cave was partially formed along the sinistral Obir Fault, close to which a high density of centimetres to decimetres long polished slickensides have been observed. The knife-sharp slip surfaces are associated with millimetre to centimetre thin layers of ultracataclasites, in either hardly deformed or protocataclastic rocks. The highly mature ultracataclasites record angular to rounded clasts, which are truncated along the polished slickensides, but clear kinematic indicators are generally missing. Injection of the ultracataclasites into the protocataclastic host rocks along millimetre-wide apophysis can be locally observed. Some of the older cataclasite generations are overprinted by stylolites and calcite veins suggesting dissolution precipitation processes after cataclastic flow. The only several centimetres-long polished slickensides with varying properties and orientations cannot have accumulated large displacements but the observed microstructures as well as the geological position in an area with several active faults suggest that the investigated fault surfaces in the Obir Caves formed during seismic slip.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10505 - Geology

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Austrian Journal of Earth Sciences

ISSN

2072-7151

e-ISSN

2072-7151

Volume of the periodical

118

Issue of the periodical within the volume

1

Country of publishing house

PL - POLAND

Number of pages

18

Pages from-to

115-132

UT code for WoS article

001512656800001

EID of the result in the Scopus database

2-s2.0-105009300607