Massive, boudinaged, rose-coloured layers up to one metre in thickness composed of 60–80 vol% spessartine-rich garnet and 15–40 quartz occur high-pressure, garnet-mica schist on Margarita I...

Low resistivity in argillaceous sandstone reservoirs may be attributed either to the effect of microporosity, or to specific effects due to clays and/or to conducting minerals. In the frame of a study on pore lining chlorite bearing sandstones, from different hydrocarbon reservoirs, measurements of cation exchange capacities and specific surface areas have been performed, on whole rocks as well...

Abstract Magnetite stability in ultramafic systems undergoing subduction plays a major role controlling redox states of the fluids liberated upon dehydration reactions, as well residual rocks. Despite their relevance for evaluation conditions, systematics and geochemistry oxide minerals have remained poorly constrained subducted Here, we present detailed petrological geochemical study magnetite...

In the last decades, helicopter-borne electromagnetic (HEM) method became a focus of interest in the fields of mineral exploration, geological mapping, groundwater resource investigation and environmental monitoring. As a standard approach, researchers use 1-D inversion of the acquired HEM data to recover the conductivity/resistivity-depth models. Since the relation between HEM data and model ...

The B and Pb isotope systems are widely applied tracers of recycling processes occurring during subduction. Studies examining these complementary systems as a pair enjoy considerable success, where B primarily records the thermal and fluid evolution of the subducting slab, whereas the tripartite Pb system constrains the source of subducted material returned to volcanic arcs. However, interpreta...

An introduction to the Bouguer anomaly map of Finland is presented. Anomaly sources from surface to upper mantle are discussed both qualitatively and quantitatively. Related density variations are reviewed. The article is based on gravity data from the Finnish Geodetic Institute supplemented by petrophysical and gravity data from the Geological Survey of Finland. The Finnish Geodetic Institute ...

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...