Rock pulverization and localization of a strike-slip fault zone in dolomite rocks (Salzach–Ennstal–Mariazell–Puchberg fault, Austria)

Schröckenfuchs, T.; Bauer, Harald; Grasemann, Bernhard; Decker, Kurt

doi:10.1016/j.jsg.2015.06.009

Cited by 22 publications

(13 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cataclasites type 2 are always very cohesive rocks, with complete cementation or eventually recrystallization (Smith et al 2011) of the finegrained matrix. Cataclasites type 1 show only localized portions of fine-grained matrix, indicating that these rocks are formed by (intra-granular) extensional fracturing and in-situ grain-size reduction by crushing of entire intermediate components with increasing deformation (Schröckenfuchs et al 2015). This results in a heterogeneous micro-structural build-up, which the authors think is also responsible for the variable porosities.…”

Section: Discussion Generation and Hydrogeological Significance Of Famentioning

confidence: 96%

“…The formation of dilation breccias here is not by hydraulic fracturing with increased fluid pressure (Tarasewicz et al 2005), but by rock pulverization without a major contribution of fluids (Schröckenfuchs et al 2015). Dilation breccias formed by rock pulverization during dynamic earthquake rupturing are characterized by sedimentation of fine-grained particles within open voids.…”

Section: Discussion Generation and Hydrogeological Significance Of Famentioning

confidence: 97%

“…Due to the low cohesion and bad mechanical properties of this type of rock, no plugs could be drilled for measurements. From hand specimens and thin sections (see also Schröckenfuchs et al 2015), the authors interpret dolostone dilation breccias as permeable units.…”

Section: Discussion Generation and Hydrogeological Significance Of Famentioning

confidence: 99%

See 2 more Smart Citations

Hydrogeological properties of fault zones in a karstified carbonate aquifer (Northern Calcareous Alps, Austria)

2016

View full text Add to dashboard Cite

This study presents a comparative, field-based hydrogeological characterization of exhumed, inactive fault zones in low-porosity Triassic dolostones and limestones of the Hochschwab massif, a carbonate unit of high economic importance supplying 60 % of the drinking water of Austria's capital, Vienna. Cataclastic rocks and sheared, strongly cemented breccias form low-permeability (<1 mD) domains along faults. Fractured rocks with fracture densities varying by a factor of 10 and fracture porosities varying by a factor of 3, and dilation breccias with average porosities >3 % and permeabilities >1,000 mD form high-permeability domains. With respect to fault-zone architecture and rock content, which is demonstrated to be different for dolostone and limestone, four types of faults are presented. Faults with single-stranded minor fault cores, faults with single-stranded permeable fault cores, and faults with multiple-stranded fault cores are seen as conduits. Faults with single-stranded impermeable fault cores are seen as conduit-barrier systems. Karstic carbonate dissolution occurs along fault cores in limestones and, to a lesser degree, dolostones and creates superposed highpermeability conduits. On a regional scale, faults of a particular deformation event have to be viewed as forming a network of flow conduits directing recharge more or less rapidly towards the water table and the springs. Sections of impermeable fault cores only very locally have the potential to create barriers.

show abstract

Section: Discussion Generation and Hydrogeological Significance Of Famentioning

confidence: 96%

Section: Discussion Generation and Hydrogeological Significance Of Famentioning

confidence: 97%

See 1 more Smart Citation

Hydrogeological properties of fault zones in a karstified carbonate aquifer (Northern Calcareous Alps, Austria)

2016

View full text Add to dashboard Cite

show abstract

“…Natural fault gouges and cataclasites are often composed of minerals that have well-defined cleavage planes, along which fracturing can occur preferentially. The anisotropy represented by cleavage planes is an intrinsic property of carbonates, phyllosilicates, feldspars and amphiboles (e.g., Faulkner et al, 2003;Rutter et al, 2007;Schröckenfuchs et al, 2015;Smeraglia et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Development of crystallographic preferred orientation during cataclasis in low-temperature carbonate fault gouge

Demurtas

Smith

Prior

et al. 2019

Journal of Structural Geology

View full text Add to dashboard Cite

Grain size reduction due to cataclasis is a key process controlling fault frictional properties during the seismic cycle. We investigated the role of cleavage planes on fracturing and microstructural evolution during cataclasis in wet and dry carbonate fault gouges (50 wt.% calcite, 50 wt.% dolomite) deformed in a rotary-shear apparatus over a wide range of slip rates (30 µms -1 to 1 ms -1 ) and displacements (0.05 to 0.4 m). During shearing, progressive strain localization forms a narrow slip zone that undergoes significant frictional heating (at high slip rates), but the bulk gouge always accommodates low finite shear strains and deforms at low temperatures. Microstructural analysis of the bulk gouges indicates that deformation occurred by brittle fracturing and twinning.Microfractures in calcite are closely spaced, often exploit cleavage r-rhomb planes, and { 1014 } occur mainly subparallel to the expected principal stress orientation (σ 1 ). Instead, twin planes typically occur sub-perpendicular to σ 1 . Electron backscatter diffraction analysis of the bulk gouges shows that calcite develops a well-defined crystallographic preferred orientation (CPO) at all investigated deformation conditions. The CPO is defined by a clustering of the calcite c-axes around an orientation sub-parallel to σ 1 . The calcite CPO is interpreted to result from grain rotation during granular flow, followed by brittle fracturing that occurred preferentially along calcite cleavage planes. This interpretation is supported by measurements of calcite grain shape-preferred orientations that show a population of elongate calcite grains oriented with their long axes subparallel to σ 1 . Our experimental results indicate that well-defined CPOs can form at low temperature in cataclastic fault rocks, and that mineral cleavage can strongly influence the evolution of grain sizes and shapes during comminution.

show abstract

“…In contrast, the erratic permeability behavior observed in pulverized samples during a first hydrostatic pressure cycle indicates that the internal damage structure is subject to additional permanent change, aside from standard structural changes that cause common hysteresis. The small particle sizes in pulverized rocks (Barber & Griffith, ; Muto et al, ) may affect the permeability; fluid flow causes erosion of small particles, which may be deposited elsewhere in the pulverized rock‐forming geopetal‐particle‐aggregates (Schröckenfuchs et al, ). Here, we have found these particles in the pore fluid system, and the X‐ray μCT images reveal that some larger aperture fractures are filled with fine‐grained material that was potentially transported from elsewhere in the sample.…”

Section: Discussionmentioning

confidence: 99%

Variation of Hydraulic Properties Due to Dynamic Fracture Damage: Implications for Fault Zones

2020

View full text Add to dashboard Cite

High strain rate loading causes pervasive dynamic microfracturing in crystalline materials, with dynamic pulverization being the extreme end-member. Hydraulic properties (permeability, porosity, and storage capacity) are primarily controlled by fracture damage and will therefore change significantly by intense dynamic fracturing-by how much is currently unknown. Dynamic fracture damage observed in the damage zones of seismic faults is thought to originate from dynamic stresses near the earthquake rupture tip. This implies that during an earthquake, hydraulic properties in the damage zone change early. The immediate effect this has on fluid-driven coseismic slip processes following the rupture, and on postseismic and interseismic fault zone processes, is not yet clear. Here, we present hydraulic properties measured on the full range of dynamic fracture damage up to dynamic pulverization. Dynamic damage was induced in quartz-monzonite samples by performing uniaxial high strain rate (> 10 0 s −1 ) experiments in compression using a split-Hopkinson pressure bar. Hydraulic properties were measured on samples subjected to single and successive loadings, the latter to simulate cumulative damage from repeated rupture events. We show that permeability increases by 6 orders of magnitude and porosity by 15% with dissipated energy up to dynamic pulverization, for both single and successive loadings. We present damage zone permeability profiles induced by earthquake rupture and how it evolves with repeated ruptures. We propose that the enhanced hydraulic properties measured for pulverized rock decrease the efficiency of thermal pressurization, when emplaced adjacent to the principal slip zone.

show abstract

Rock pulverization and localization of a strike-slip fault zone in dolomite rocks (Salzach–Ennstal–Mariazell–Puchberg fault, Austria)

Cited by 22 publications

References 92 publications

Hydrogeological properties of fault zones in a karstified carbonate aquifer (Northern Calcareous Alps, Austria)

Hydrogeological properties of fault zones in a karstified carbonate aquifer (Northern Calcareous Alps, Austria)

Development of crystallographic preferred orientation during cataclasis in low-temperature carbonate fault gouge

Variation of Hydraulic Properties Due to Dynamic Fracture Damage: Implications for Fault Zones

Contact Info

Product

Resources

About