نتایج جستجو برای: rocks
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Western Turkey has been dominated by N–S extension since the Early Miocene. The timing and cause of this N–S extension and related basin formation have been the subject of much debate, but new data from the Bigadiç borate basin provide insights that may solve this controversy. The basin is located in the Bornova Flysch Zone, which is thought to have formed as a major NEtrending transform zone d...
pb-zn deposits in the kurdistan region, northern iraq, have occurred mainly as a stratabound and open-space filling ore bodies. they are hosted by dolostone and dolomitic-limestone of platform carbonates. the ore deposits at the studied dure and lefan areas are respectively hosted by kurra chine (upper triassic) and bekhme (upper cretaceous) formations. pyrite, sphalerite and galena are the maj...
granitoid rocks of kaje area, northwest ferdows, with the composition of diorite, monzodiorite, monzonite, monzogranite, syenogranite and granite, with calk-alkaline and high potassium affinities, have trace and rare earth element geochemical characteristics similar to those from subduction zones, belonging to i-type granitoid rocks. most of these rocks are oxidized (magnetite series), while on...
Introduction: The ~10 km in diameter, deeply eroded Paasselkä impact structure [1-3] (Fig. 1), hosted by ~1.9 Ga Paleoproterozoic crystalline rocks of the Svecofennian Domain of the Baltic Shield (e.g., [4]), is the third largest of eleven impact structures currently known in Finland [5]. A recent geological summary of the Paasselkä impact structure and a petrographic-geochemical description of...
Characterization of porosity in carbonate rocks is important in the oil and gas industry since a major hydrocarbons field is formed by this lithology and they have a complex media porous. In this context, this research presents a study of the pore space in limestones rocks by x-ray microtomography. Total porosity, type of porosity and pore size distribution were evaluated from 3D high resolutio...
More than 200 specimens from different occurrences of the Rogaland igneous complex and surrounding granulite facies metamorphic rocks (S. W. Norway) have been analysed by a direct non-destructive proton induced gamma-ray emission (PIGE) technique. The fluorine contents vary from < 25 ppm to 3500 ppm. There is a good correlation between the concentration of fluorine and that of phosphorus for ig...
We consider a simplified model for two-phase flows in one-dimensional heterogeneous porous media made of two different rocks. We focus on the effects induced by the discontinuity of the capillarity field at interface. We first consider a model with capillarity forces within the rocks, stating an existence/uniqueness result. Then we look for the asymptotic problem for vanishing capillarity withi...
The existence of microbial communities living inside desert rocks has been reported by FRIEDMANN et al. (1967, 1976), first in rocks collected from the hot and dry Negev desert and later in rocks in the frigid Ross Desert of Southern Victoria Land, Antarctica. The extremely inhospitable climatic conditions in both places has led to the suggestion that these organisms have very low rates of met...
CONTENTS Page Introduction .................................................................................................................. 127 Megascopic structures ...................................................................................................... 128 Hand-specimen petrology .....................................................................................................
Samarium-neodymium isotopic data on whole rocks and minerals of the Sudbury Complex in Canada gave an igneous crystallization age of 1840 +/- 21 x 10(6) years. The initial epsilon neodymium values for 15 whole rocks are similar to those for average upper continental crust, falling on the crustal trend of neodymium isotopic evolution as defined by shales. The rare earth element concentration pat...
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