Anomalous patterns of clay minerals in fault zones

Water–Rock Interaction Processes in Tíscar and Larva Active Faults (Betic Cordillera, SE Spain)

“…Nevertheless, possible pollution from agricultural practices could influence their high concentration. (12). This water has a normal or low B content (<0.22 ppm).…”

“…in the octahedral sheet). Tectonic and fluid circulation can affect the generation and enrichment of clays in fault zones [12]. Mineral processes associated with cataclasis and fluid infiltration can ex- A network of slip surfaces can be observed in these materials.…”

“…Tectonic and fluid circulation can affect the generation and enrichment of clays in fault zones [12]. Mineral processes associated with cataclasis and fluid infiltration can exhibit an important role in producing appropriate microenvironments favoring the nucleation of new minerals.…”

“…Therefore, the presence of smectite and cross-cutting veins filled with dolomite (Figure 8B) suggests that recurrent inputs of fluids circulating through the fault were responsible for the alteration pattern of the fault rocks. The chemical composition of the waters in rock pores affects the precipitation of neoformed clays in fault zones [12,55]. The precipitation of dolomite in veins can be used as an indicator of the high salinity of the fluids circulating in fault rocks [7,56].…”

“…The crystallization of mineral phases in fault areas is controlled by the chemistry of circulating fluid, the characteristics of the fault rocks, and the physical factors present at the time of mineralization. The chemical composition of groundwater fluids circulating through active fault zones can be affected by geological processes, sometimes linked to the nucleation and propagation of earthquake processes that occur in these areas, such as (i) the discharge of water and other liquids produced by the consolidation or liquefaction of shallow sediments, see, e.g., [7]; (ii) dryness reactions of clay minerals in depth zones [8][9][10][11]; (iii) and dissolution-precipitation processes in rocks through which groundwater has passed, see, e.g., [12]. The spatio-temporal variations in groundwater hydrochemical constituents produced by these processes could be used in future studies on earthquake prediction [13].…”