In this study, we describe a sedimentary deposit situated above Ascunsă Cave (SW Romania) that should be in depositional connection with coeval stalagmites from the cave. We excavated 2.5 m deep soil profile and took contiguous bulk samples every 5 cm. Soil were analyzed for clay mineralogy, grain size, chemical composition, magnetic susceptibility, stable carbon isotopes. Radiocarbon dating re...

Clay minerals are the signature of hydrothermal alterations related to fluid circulation in volcanic and crystalline rocks. In French part Upper Rhine Graben, deep-seated granites, illitic (illite I/S mixed layers (ml)) typical products structurally-controlled argillic alteration Paleozoic granitic basement. new Illkirch geothermal well, GIL-1, drill-cuttings were studied with various petrograp...

University of Modena and Reggio Emilia – Earth Sciences Department, Via S. Eufemia 19, 41100 Modena, Italy, University of Trento, Department of Materials Engineering and Industrial Technologies, Via Mesiano 77, 38050 Trento, Italy, Portland State University, Department of Geology, PO Box 751, Portland, OR 97207-0751, USA, and Department of Physics and Astronomy, Michigan State University, East ...

ABSTR&CT Seven brickmaking clays from various geological horizons have been studied by differential thermal and X-ray methods. The minerals detected included kaolinite, illite, montmorillonite, chlorite, swelling chlorite, calcite and quartz, and rough estimates were made of the quantities present. For the same clays, deformation-under-load was measured at four different heating rates, and stre...

Principal component regression (PCR) was used to develop calibration and prediction models for determination of mineral content of complex mineral mixtures by utilizing attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra. The typical constituents of oil shale such as dawsonite, nahcolite, quartz, dolomite, illite, albite, analcime, and kerogen were used to prepare samples...

Clay minerals, which totally make up 4-5% of the earth’s crust, are generally classified into three different phyllosilicate: illites, smectites and kaolins. Of these, kaolin generally has the lowest Fe content and illite the highest; however, smectite also has appreciable Fe contents (<30 wt %). In this editorial, the focus is restricted to the Fe-bearing smectites, since smectites are ubiquit...

This paper discusses the processes and mechanical factors that define the seismogenic zone and the updip transition from seismic to aseismic faulting. We review friction laws for granular and clay-rich fault zones and discuss them in the context of the mechanics of stick-slip and the requirements for instability. Seismogenic faulting is driven by the unstable release of stored elastic energy, a...

Uplift of the Tibetan Plateau since the Late Miocene has greatly affected the nature of sediments deposited in the Qaidam Basin. However, due to the scarcity of continuously dated sediment records, we know little about how minerals responded to this uplift. In order to understand this response, we here present results from the high-resolution mineral profile from a borehole (7.3-1.6 Ma) in the ...