نتایج جستجو برای: fractured rocks by fault
تعداد نتایج: 7096324 فیلتر نتایج به سال:
kuh- e -zar gold deposit located 35 km west of torbat-e-heydaryeh, (khorassan e- razavi province), east of iran. this deposit is a specularite-rich iron oxide type (iocg). this mine is situated within khaf-bardascan volcanic plutonic belt. based on recent exploration along this belt, several iocg type system plus kuh-e-zar deposit are discovered. in the study area, several type of tuff and lava...
This paper presents the new geochemical isotopes Sr and Nd, and the mineralization data for the south Neyshabour volcanic rocks located in NE Iran. Based on the chemical classifications, the studied rocks are basaltic trachy andesite, trachy andesite, trachyte, and trachy dacite in composition. All the analyzed volcanic rocks display enrichment in light rare earth elements (LREE) relative to th...
[1] Shaking-induced changes in permeability have been invoked to explain a wide range of hydrologic responses to earthquakes. We measure the evolution of permeability in fractured sandstone in response to repeated shaking under undrained conditions. The frequency and amplitude of the imposed shaking are similar to those from earthquakes at distances of a fault length from the ruptured fault. To...
Typomorphic features of placer gold the Anabar region were studied as predictive-exploration criteria. The target study was to determine typomorphic related intermediate sources (paleo-placers) and supposed nearby primary ore occurrences. Two varieties identified. first variety is well-rounded high-fineness lamellar with a highly modified internal structure. This native associated sources, Neog...
A sequence of earthquakes occurred in 2008 in the Meruoca granitic pluton, located in the northwestern part of the Borborema Province, NE Brazil. A seismological study defined the seismic activity occurring along the seismically-defined Riacho Fundo fault, a 081° striking, 8 km deep structure. The objective of this study was to analyze the correlation between this seismic activity and geologica...
The purpose of this study is developing of a model for estimation of elastic modulus of intact rocks. Mechanical rock excavation projects require static modulus of elasticity (E) of the intact rock material. High-quality core specimens of proper geometry are nedded for the direct determination of this parameter. However, it is not always possible to obtain suitable specimens from highly fractur...
Radon (Rn) constitutes a good geochemical tracer for neotectonic activity in faults since associated fracturing near the surface favours fluid escape to atmosphere. In this contribution, we measured Rn concentration air inside karst caves constraints recent fault Cantabrian Mountains (N Spain). Rock formations exhumed during uplifting of record long history fracturing, which has potential conne...
The Taltal area, which lies within the coastal cordillera of northern Chile, is dominated by a group of major active faults that cut a eugeosynclinal section of predominantly Jurassic andesites overlying Paleozoic metamorphic and plutonlc rocks and intruded by Late Mesozoic plutons. The Atacama fault, a suggested regional strike-sllp fracture parallel to the coastline, has been obliquely cut an...
Rupture fronts can cause fault displacement, reaching speeds up to several ms(-1) within a few milliseconds, at any distance away from the earthquake nucleation area. In the case of silicate-bearing rocks the abrupt slip acceleration results in melting at asperity contacts causing a large reduction in fault frictional strength (i.e., flash weakening). Flash weakening is also observed in experim...
Imaging and characterizing fractured shale reservoirs constitute significant challenges. We introduce a workflow and illustrate the application of instantaneous spectral analysis with the aid of a case study on fractured shale reservoirs. With the well log modeling, frequency dependent energy and phase are improved by removing the wavelet overprint. Extracted frequency dependent energy and phas...
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