With an aim to increase the understanding about the isotopic and chemical heterogeneity of
calcites in water-conducting fracture zones with different crystalline wall rock compositions at
different depths, we present trace element chemistry, isotopic composition (δ 18 O, δ 13 C,
87 Sr/86 Sr) and biomarkers of euhedral low-temperature fracture-coating calcite.
Paleohydrogeological fluctuations and wall rock influence on the hydrochemistry in the deep
groundwater are explored. Samples are from several fracture zone sub-fractures (at− 360 …