نتایج جستجو برای: diagenetic processes

تعداد نتایج: 529387  

عابدینی, علی, کلاگری, علی اصغر ,

East of Shahindezh (south of West Azarbaidjan province), as a part of Irano-Himalayan karst bauxite belt, comprises discontinuous layers and lenses of bauxite, laterite, and kaolin within the Ruteh carbonate formation (Middle- Upper Permian). The XRD analyses show that the lateritic ores have rather simple mineralogy, and consist of hematite, boehmite, and kaolinite as major phases accompanied ...

2009
J. J. Middelburg L. A. Levin

The intensity, duration and frequency of coastal hypoxia (oxygen concentration <63μM) are increasing due to human alteration of coastal ecosystems and changes in oceanographic conditions due to global warming. Here we provide a concise review of the consequences of coastal hypoxia for sediment biogeochemistry. Changes in bottomwater oxygen levels have consequences for early diagenetic pathways ...

2017
L. J. Wooldridge R. H. Worden J. Griffiths A. Thompson P. Chung

The presence of clay-sized particles and clay minerals in modern sands and ancient sandstones has long presented an interesting problem, because primary depositional processes tend to lead to physical separation of fineand coarse-grained materials. Numerous processes have been invoked to explain the common presence of clay minerals in sandstones, including infiltration, the codeposition of floc...

2005
K. G. McQueen

Metals are largely derived from the mantle or crust by partial melting and fluid-related leaching. Ligands can be provided from the same sources, or from the atmosphere, hydrosphere and biosphere. Transport is mainly by mechanical or mass transfer mechanisms and by fluids. On and near the surface, biological processes can also concentrate and transport ore components or remove non-ore component...

2009
Y. Zhao S. M. McLennan N. J. Tosca

Introduction: The APXS (Alpha-Particle X-Ray Spectrometer) onboard the Mars Exploration Rovers (MER) has returned element abundances of over 200 soil and rock samples at both the Opportunity and Spirit landing sites [1]. Besides major elements, a selection of trace element concentrations including Ni, Cr, and Zn are also available. These data demonstrate that the trace element abundances of Mer...

Journal: :فیزیک زمین و فضا 0
محمدحسین نعمتی غلامحسین نوروزی محمدعلی ریاحی

nowadays, by complication of production mechanisms from reservoirs and depletion of most of the reservoirs in iran, secondary production has become more important. regarding the nature of iranian reservoirs and carbonate inherencies and diagenetic and tectonic effects on these reservoirs, we see heterogeneities in them which cause uncertainty in predictions and performance of these reservoirs. ...

Journal: :Astrobiology 2011
Roger E Summons Jan P Amend David Bish Roger Buick George D Cody David J Des Marais Gilles Dromart Jennifer L Eigenbrode Andrew H Knoll Dawn Y Sumner

The Mars Science Laboratory (MSL) has an instrument package capable of making measurements of past and present environmental conditions. The data generated may tell us if Mars is, or ever was, able to support life. However, the knowledge of Mars' past history and the geological processes most likely to preserve a record of that history remain sparse and, in some instances, ambiguous. Physical, ...

2011
Roger E. Summons Jan P. Amend David Bish Roger Buick George D. Cody David J. Des Marais Gilles Dromart Jennifer L. Eigenbrode Andrew H. Knoll Dawn Y. Sumner

The Mars Science Laboratory (MSL) has an instrument package capable of making measurements of past and present environmental conditions. The data generated may tell us if Mars is, or ever was, able to support life. However, the knowledge of Mars’ past history and the geological processes most likely to preserve a record of that history remain sparse and, in some instances, ambiguous. Physical, ...

Journal: :journal of tethys 0

the badamu formation (upper toarcian-middle bajocian) mainly consists of limestone and shale and has is cropped out in east of iran. the badamu formation conformably overlays shemshak formation and is underlaid sharply by hojedk formation in kerman area and is underlaid gradually by baghamshah formation in tabas and southern khorasan areas. the aim of this work is petrographical study of rocks ...

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