نتایج جستجو برای: geochemical unit

تعداد نتایج: 406665  

2007

Exploration geochemistry continues to be a major contributor to mineral exploration programs at all scales. The decade has spanned a complete economic cycle in the minerals industry, during which there has been a change in exploration emphasis from the dominance of Au and diamonds to the addition of a range of base metals and the recent revival of U exploration. Increasing metal prices and the ...

2016
Shichun Huang Frederick A. Frey Michael J. Vollinger J. Michael Rhodes Qun Zhang

Geochemical analyses of stratigraphic sequences of lava flows are necessary to understand how a volcano works. Typically one sample from each lava flow is collected and studied with the assumption that this sample is representative of the flow composition. This assumption may not be valid. The thickness of flows ranges from <1 to >100 m. Geochemical heterogeneity in thin flows may be created by...

Journal: :Elements 2022

ترابی, قدرت , گلی, زهرا ,

Eocene volcanic rocks in SW of Choupanan are exposed along the Choupanan fault as lava with andesite, trachyandesite to dacite composition and pyroclastic rocks. This area is a part of Central Iran (Yazd block). Andesite is the most predominant rock unit of the area and is composed of feldspars (andesine, oligoclase, and sanidine), amphibole (magnesio hastingsite, magnesian hastingsite, magnesi...

ترابی, قدرت , شیردشت زاده, نرگس,

Eocene volcanic rocks in NE of Ordib, have a very good exposures near and along the Turkmeni-Ordib fault. These rocks, that are situated in the inner part of the Central Iran and margin of the Yazd block, comprise trachyte, trachy-andesite and basaltic trachy-andesite. Trachy-andesite is the pervasive rock unit. Rock forming minerals of these rocks are chloritized olivine, plagioclase, pyroxene...

2003
Anders Meibom Don L. Anderson

A fundamental challenge in modern mantle geochemistry is to link geochemical data with geological and geophysical observations. Most of the early geochemical models involved a layered mantle and the concept of geochemical reservoirs. Indeed, the two layer mantle model has been implicit in almost all geochemical literature and the provenance of oceanic island basalt (OIB) and mid-ocean ridge bas...

Discrimination of the blind and dispersed mineralization deposits is a challenging problem in geochemical exploration. The frequency domain (FD) of the surface geochemical data can solve this important issue. This new exploratory information can be achieved using the interpretation of FD of geochemical data, which is impossible in spatial domain. In this research work, FD of the surface geochem...

2001
Colin E. Dunn Gwendy E.M. Hall Graham Nixon

The surface geochemical response to bedrock containing elevated levels of the platinum group elements (PGE) is commonly so subtle that standard geochemical methods are insufficiently sensitive to assist the exploration geologist. At the Geological Survey of Canada, recent research on analytical methods by one of us (GEMH) has been directed toward the development of a selective leach of soils an...

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