Fault Core Thickness: Insights from Siliciclastic and Carbonate Rocks

Figure 2

(a, b) Pictures of the outcrop with its sketch illustrating the method for measuring fault core thickness at the outcrop and on photos. The data collection started at the fault position on the scanline and fault core thickness (black lines) was measured perpendicular to fault walls at regular increments (levels) along fault height, in this case, every 60 cm. After Johannessen [70]. Note that the upper part of the figure might be considered as two faults with separate fault cores or splays of the same fault cropping out a lens. NB in (b) stands for notebook. (c–f) Examples of fault rocks (pictures and sketches) in the studied fault cores for carbonate rocks of Maiella and siliciclastic rocks of Utah. Multiple slip surfaces, carbonate lenses, karst (not included in the measurements), and breccia are among the structures found in the fault core of carbonate rocks in the strike-slip fault in Maiella in (c) and (d). Note the presence of several slip surfaces and shaley gouge with rock fragments as well as breccia and cataclasite in a normal fault (R-191) in (e) and (f).

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(b)

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