In-Situ Shattered Dolostones are Geological Markers of Earthquake Ruptures

Thu, 06/04/2017

Studies looked at the occurrence of hundreds of meters thick belts of intensely fragmented dolostones along a major transpressive fault zone in the Italian Southern Alps.

Florian Fusseis and colleagues from other European research institutions publish results of their collaborative research in Earth & Planetary Science Letters which show that the presence of in-situ shattered dolostones in the Foiana Fault Zone can be used in earthquake hazard studies as evidence of seismic ruptures at shallow depths.

The group investigated the possibility that fragmented rocks in carbonate fault zones may have a coseismic dynamic origin, reporting on the occurrence of thick belts of in-situ shattered dolostones along a major transpressive fault zone in the Italian Southern Alps and tested the mechanical behavior of the dolomitic host rocks in compression over a wide range of strain rates to constrain the deformation conditions under which in-situ shattering occurs. The group used image analysis techniques to discriminate between quasi-static and dynamic fracture patterns and inferred in-situ shattering as a dynamic coseismic process.

These findings allowed the group to consider the implications of their experimental results for the mechanics of earthquakes and the scaling relationships of fault zones in carbonates.

 

Further reading: Earth & Planetary Science Letters - March 2017