نتایج جستجو برای: the materials lithology

تعداد نتایج: 16111823  

Journal: :Collection of Scientific Works of the Institute of Geological Sciences of the NAS of Ukraine 2015

2013
M. A. Mooney M. Karaoulis A. Revil

In this paper, we explore the fundamental physics behind the application of electrical resistivity and induced polarization during tunnel boring machine (TBM) mining. Using finite element (FE) analysis, we model the electric field created when current is injected into the surrounding ground via electrodes in the TBM cutterhead. The FE analysis simulates a variety of materials and conditions inc...

2008
Kathleen E. Mandt Shanaka L. de Silva James R. Zimbelman David A. Crown

[1] The geologic origin of the Medusae Fossae Formation (MFF) has remained a mystery despite three decades of research. To better constrain its formation, an in-depth analysis of observations made in the literature was combined with a new survey of over 700 Mars Orbiter Camera narrow-angle images of the MFF to identify morphologic characteristics and material properties that define this formati...

Journal: :Journal of environmental quality 2003
Steven D Siciliano Al Sangster Chris J Daughney Lisa Loseto James J Germida Andrew N Rencz Nelson J O'Driscoll David R S Lean

In the relatively pristine ecosystem in Kejimkujik Park, Nova Scotia, methylmercury (MeHg) concentrations in loons, Gavia immer, are among the highest recorded anywhere in the world. This study investigated the influence of bedrock lithology on MeHg concentrations in wetlands. Twenty-five different wetland field sites were sampled over four different bedrock lithologies; Kejimkujik monzogranite...

2006
R. Gellert D. W. Ming R. V. Morris D. W. Mittlefehldt S. W. Squyres A. Yen

Introduction: Uniquely high levels of phosphorus and titanium were observed in several samples [1-3] by the APXS x-ray fluorescence measurements as the MER Spirit rover climbed Husband Hill (Columbia Hills, Gusev crater, Mars). A careful study of many such samples and their geochemical variability has revealed additional elements in this pattern, and that the derived multi-element signature is ...

Journal: :Journal of Geographical Systems 2007
D. M. Allen Nadine Schuurman Q. Zhang

Modeling the geologic architecture of an aquifer and visualizing its three-dimensional structure require lithologic data recorded during well drilling. Uncertainties in layer boundaries arise due to questionable quality of drilling records, mixing during the drilling process, which results in blurred contacts, and natural heterogeneity of the geologic materials. An approach for modeling and vis...

2008
Yan Zhao Zicheng Yu Fahu Chen Jiajia Li

We present lithology and fossil pollen data from a 384 cm sediment section from Qingtu paleolake in arid northwest China and discuss their environmental interpretations. The chronology was controlled by four accelerator mass spectrometry (AMS) radiocarbon dates on peat and bulk lake sediments. Lithology changes suggest a general sequence of local environment shifts from a non-lake environment b...

2003
B. L. Jolliff R. L. Korotev R. A. Zeigler C. Floss

Introduction: Northwest Africa 773 is one of the more unusual lunar meteorites found in recent years because it contains a prominent clast lithology, which appears to be an olivine-rich cumulate [1-4] and because it is a very-low-Ti (VLT) mare breccia with relatively high incompatible-trace-element concentrations and LREE/HREE enrichment [3]. A lunar origin was verified by Fagan and coworkers [...

Journal: :journal of tethys 0

the lithologies of regions, which located near the collision zone, are very different from other geology setting. mapping in these areas needs extensive and exact studies and tools because of the variety of rocks, intensive tectonic uplift and complicated units. hyperspectral sensor is one of the most advanced tools with hundreds of bands that each measures a very narrow range of wavelengths an...

Journal: :Collection of Scientific Works of the Institute of Geological Sciences of the NAS of Ukraine 2008

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