Geochemistry of Fluid Inclusions in Travertines From Western and Northern Turkey: Inferences on the Role of Active Faults in Fluids Circulation

Abstract

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 Reşadiye (Turkey), sited in seismic regions and next to thermal springs. These travertines formed ~24,500–50,000 (Pamukkale) and ~240–14,600 years (Reşadiye) BP. We characterize fluid inclusions (FIs) and studied concentration of H2O, CO2, O2 + N2, and 3He, 4He, 20Ne, and 40Ar, and bulk composition (trace elements and δ13C‐δ18O). FIs from both localities are mainly primary with low salinity and homogenization temperature around 136–140 °C. H2O is the major component followed by CO2, with the highest gas content measured in Pamukkale travertines. Concentrations of Ne‐Ar together with O2 + N2 indicate that travertines from both areas precipitated from atmosphere‐derived fluids. The 3He/4He is 0.5–1.3 Ra in Pamukkale and 0.9–4.4 Ra in Reşadiye. Samples with R/Ra > 1 are modified by cosmogenic 3He addition during exposure to cosmic rays. Excluding these data, FIs of Reşadiye 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 δ13CCO2 and δ18O of bulk rocks, we infer that travertines formed involving crustal‐ (mechanochemical rather than organic) and mantle‐derived CO2. Trace elements of Pamukkale and Reşadiye show comparable rare earth element patterns. We conclude that travertines formed in response of seismogenetic activity.

Manifestations of Quaternary syn‐eruptive fluid circulations on carbonate veins, Central Anatolian Volcanic Province

“…The remarkable heterogeneous crystallisation indicates that the continuous fluid flow with high discharge rate resulted in carbonate deposition in a turbulent environment (e.g. Rizzo et al ., 2019).…”

Mineral Crushing Methods for Noble Gas Analyses of Fluid Inclusions

“…Noble gases are investigated in fluid inclusions occurring in a variety of minerals, e.g., in olivine, pyroxene, amphibole, sulphides, or basaltic glasses; these are of interest when questions about magma origins and mantle contributions are Crustal rock studies (48) Climate studies (9) Deep water studies (4) Mantle rock studies (49) Method studies (7) Ore studies (45) Extraterrestrial rocks studies (3) TWO CRUSHER 3 Geofluids investigated. Studies of crustal composition and origin have analysed fluid inclusions found in olivine, calcite, fluorite, eclogite, corundum, quartz, or whole rock pieces (e.g., [58][59][60][61]). Common minerals relevant for noble gas analyses in fluid inclusions for ore studies are ore-associated minerals like quartz, pyrite, calcite, or fluorite (e.g., [3,40,53,62]).…”

“…Another crusher uses single-step systems with a stainless-steel bowl in ultrahigh vacuum conditions which can apply up to 2000 bar pressure [98]. This crushing system is capable to process six samples simultaneously [61,100,101]. [99,102] used a combination of a 1 cm diameter and a 6 to 10 cm long stainless-steel sampler, a hydraulic piston with applied pressure up to 200 bar, and a stainless-steel plate (AISI 316 LRN) placed below the sampler.…”

Fissure Ridges: A Reappraisal of Faulting and Travertine Deposition (Travitonics)

“…The results suggest that the events recorded in Ca-carbonate veins indicate an epicenter with a distance of <200 km and high-intensity (I > VI) paleoearthquakes; thus, this tool has advantages over traditional paleoseismological methods for the understanding of long-term earthquake behavior. In this view, it should be possible to use age determination to reconstruct the seismicity and its recurrence [23,65,100], the fault dilatation rate [82], the age of a fault [36,65,112,116], an assessment of the slip rate [124], and relationships between faulting and fluid properties in geothermal fields [2,13,35,86,94,132,[151][152][153][154].…”