Akademik Veri Yönetim Sistemi
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, cilt.20, sa.11, ss.5473-5498, 2019 (SCI-Expanded)
The understanding of the relationship between the geochemistry of fluids circulating during travertine deposition and the presence of active faults is crucial for evaluating the seismogenetic potential of an area. Here we investigate travertines from Pamukkale and Resadiye (Turkey), sited in seismic regions and next to thermal springs. These travertines formed similar to 24,500-50,000 (Pamukkale) and similar to 240-14,600 years (Resadiye) BP. We characterize fluid inclusions (FIs) and studied concentration of H2O, CO2, O-2 + N-2, and He-3, He-4, Ne-20, and Ar-40, and bulk composition (trace elements and delta C-13-delta O-18). FIs from both localities are mainly primary with low salinity and homogenization temperature around 136-140 degrees C. H2O is the major component followed by CO2, with the highest gas content measured in Pamukkale travertines. Concentrations of Ne-Ar together with O-2 + N-2 indicate that travertines from both areas precipitated from atmosphere-derived fluids. The He-3/He-4 is 0.5-1.3 Ra in Pamukkale and 0.9-4.4 Ra in Resadiye. Samples with R/Ra > 1 are modified by cosmogenic He-3 addition during exposure to cosmic rays. Excluding these data, FIs of Resadiye are mostly atmosphere-derived. This implies a shallow formation where the circulation was dominated by meteoric waters, which is consistent with their young age. Instead, FIs of Pamukkale show mixing of mantle-, crustal-, and atmosphere-derived He, indicating that these travertines formed in lithospheric fractures. Based on the delta C-13(CO2) and delta O-18 of bulk rocks, we infer that travertines formed involving crustal- (mechanochemical rather than organic) and mantle-derived CO2. Trace elements of Pamukkale and Resadiye show comparable rare earth element patterns. We conclude that travertines formed in response of seismogenetic activity.