نتایج جستجو برای: geochemical elements estimation

تعداد نتایج: 545090  

Journal: :journal of sciences islamic republic of iran 0
a.a calagari

biglar permo-triassic bauxite deposit is located in ~15 km northwest of abgarm, southwest of ghazvin province, west of central iran. it consists of 8 stratiform and discontinuous bauxite lenses lying along the contact of ruteh (permian) and elika (triassic) carbonate formations. petrographically, the bauxite ores exhibit collomorphic-fluidal, pseudo-breccia, pseudo-porphyritic, panidio-morphic-...

2016
Jaana Jarva Timo Tarvainen Reijo Salminen

This study provides an overview on the development of the guidelines and legislation related to soil contamination in Finland, with the main focus on geochemical baselines. The use of geochemical baseline surveys in the assessment soil contamination in Finland and in some other countries is briefly discussed and the current practices in Finland are presented. Finally, the geochemical baselines ...

Journal: :The Science of the total environment 2015
Bhavna Arora Binayak P Mohanty Jennifer T McGuire

Predicting and controlling the concentrations of redox-sensitive elements are primary concerns for environmental remediation of contaminated sites. These predictions are complicated by dynamic flow processes as hydrologic variability is a governing control on conservative and reactive chemical concentrations. Subsurface heterogeneity in the form of layers and lenses further complicates the flow...

ژورنال: کواترنری ایران 2019
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Introduction In theory, the bulk composition of the sediment may provide a way of determining the provenance of this material if there is sufficient diversity in the bedrock compositions. However, sediment compositions may be changed from the original bedrock as a result of transport and chemical weathering. The geochemistry of bedload and suspended sediments has been used by many workers to d...

1999
Edward Callender Liba Granina

Major element mass balances for Lake Baikal are calculated with mostly previously published data for soluble fluxes and new, unpublished data for riverine suspended particulate matter chemistry. Physical transport seems to be the most important riverine process. The elements Ca, Mg, and Na seem to be very mobile in the weathering mantle and K and Si seem to be relatively mobile. A comparison of...

2004
Alireza Panahi Qiuming Cheng Graeme F. Bonham-Carter

Combined geostatistical and multifractal power-spectrum modelling of geochemical distributions can provide suitable indicators of metal dispersion, and is capable of analysing complex problems for targeting potential areas for mineral exploration. A case study analysing lake sediment geochemical data for the Gowganda area is presented and development of the methodology for spatial analysis of t...

2011
Chaosheng Zhang Ya Tang Xianli Xu Ger Kiely

It is challenging to perform spatial geochemical modelling due to the spatial heterogeneity features of geochemical variables. Meanwhile, high quality geochemical maps are needed for better environmental management. Soil organic C (SOC) distribution maps are required for improvements in soil management and for the estimation of C stocks at regional scales. This study investigates the use of a g...

2002
Christian Koeberl

Spherule layers in the ~ 3.4 Ga Barberton Greenstone Belt, South Africa, have been interpreted as being the result of large asteroid or comet impacts on the early earth. This interpretation was based, among other arguments, on the enr ichment of siderophile elements, especially the platinum group elements. We made a detailed mineralogical, petrological and geochemical study of spherule bed samp...

2017

Before the 1960s, comparisons between the distribution of trace elements in the environment and health in the United Kingdom were primarily confined to ad hoc studies in areas associated with particular agricultural disorders or with unusual human mortality or morbidity records. More recently, increasing interest in the importance of trace elements in crop and animal production and in the hazar...

2008
Jun Korenaga

[1] The Urey ratio describes the contribution of internal heat production to planetary-scale energy balance, and knowing this thermal budget for Earth is essential to understand its long-term evolution. Internal heat production is provided by the decay of radiogenic elements, whose budget is constrained by geochemical models of Earth. Understanding the thermal budget thus requires contributions...

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