Metamorphic index mineral zones, pressure– temperature (P–T) conditions, and CO2–H2O fluid compositions were determined for metacarbonate layers within the Wepawaug Schist, Connecticut, USA. Peak metamorphic conditions were attained in the Acadian orogeny and increase from 420 C and 6.5 kb in the low-grade greenschist facies to 610 C and 9.5 kb in the amphibolite facies. The index minerals olig...

Lithium concentrations and isotopic compositions in the country rocks (amphibolites and schists) of the Tin Mountain pegmatite show systematic changes with distance to the contact. Both Li and δLi decrease dramatically along a ∼10m traverse from the pegmatite into amphibolite, with Li concentration decreasing from 471 to 68ppm and δLi decreasing from +7.6 to −19.9. Rubidium and Cs also decrease...

Archean supracrustal sequences of pelitic, quartzitic, calcareous and mafic compositions in the central Laramie Mountains, Wyoming, have been affected by two metamorphic events: a 1.78 Ga amphibolitegrade regional metamorphism, and a 1.43 Ga contact metamorphism resulting from the intrusion of the Laramie Anorthosite Complex (LAC). Rb–Sr whole-rock isotopic data from both outside and within the...

Mineralogical and petrographic studies require analytical methods capable to underline the repartition of major trace elements within geological samples. The EPMA (Electron Probe Micro Analyzer) conventional method used for such investigation, but on restrictive zones, is verge be reached by μLIBS (micro Laser-Induced Breakdown Spectroscopy) μXRF X-Ray Fluorescence) techniques allowing elementa...

Several physical parameters and anisotropy related to rock textural arrangements, schistosity weakness planes such as cracks joints affect the P-wave velocity (VP). First, VP of quartz-mica schist a common type widespread metamorphic was compared with jointed homogeneous limestone specimens clarify effect these two different types anisotropies. The results showed that texture is stronger than l...

The accuracy, reliability and best practises of Tiin-quartz thermobarometry (TitaniQ) in greenschist facies rocks have not been established. To address these issues, we measured Ti concentrations in rutile-bearing samples of moderately deformed, partially recrystallized quartzite and vein quartz from the Hsüehshan range, Taiwan. The spread of Ti concentrations of recrystallized grains in quartz...

Abstract The timing of deformation and associated gold mineralization in SE California, USA, is contentious, partly due to the challenges involved with dating ductile deformation. We therefore combine modern geo- thermochronology field microscopic observations show that Cargo Muchacho Mountains preserve evidence northward thrusting a kilometer-scale shear zone during Late Cretaceous Laramide Or...

Introduction: The recognition of low-pressure shock-metamorphic effects in quartz is of increasing importance in studies attempting to verify an impact origin for highly eroded structures [1], recognize sedi-mentary-target impacts characterized by a wide range of shock-pressure regimes, and identify distal impact-ejecta layers or impact-tsunamiites where high-pressure indicators may be rare or ...

Compressional wave velocities (Vp) in quartz aggregate were measured to quantify the effect of pore fluid (H2O) on Vp at high pressure-temperature (P-T). Ultrasonic measurements were conducted on dry and wet quartz aggregate from room temperature to 500°C at 0.5 GPa using a piston cylinder apparatus. The experiment showed a 4% decrease in measured Vp in quartz aggregate with increasing H2O cont...