نتایج جستجو برای: geochemical indicator

تعداد نتایج: 87188  

2014
Brandon Lee Drake Wirt H. Wills Marian I. Hamilton Wetherbee Dorshow

Strontium isotope sourcing has become a common and useful method for assigning sources to archaeological artifacts.In Chaco Canyon, an Ancestral Pueblo regional center in New Mexico, previous studiesusing these methods have suggested that significant portion of maize and wood originate in the Chuska Mountains region, 75 km to the West [corrected]. In the present manuscript, these results were t...

2015
Lei Dou Tingting Li L. Dou T. T. Li

Soil heavy metal pollution is one of the main environmental problems in Pearl River Delta Economic Zone of China. Based on multi-purpose regional geochemical survey, regional eco-geochemical assessment, local eco-geochemical assessment and comprehensive appraisal, the eco-geochemical survey and assessment in Pearl River Delta Economic Zone of 41,698 km2 were completed. Samples from soils were c...

Journal: :Geobiology 2013
J Huang X Chu T W Lyons N J Planavsky H Wen

Acanthomorphic acritarch fossils, including some interpreted to be the fossils of the earliest animal embryos, first appear in the lower Doushantuo Formation of the Yangtze Gorges area (YGA). Further, the complete paleontological and geochemical record for the YGA has played a central role in defining the global biological and geochemical backdrop that presaged and witnessed the dawn of diverse...

Journal: :Geochemistry-exploration Environment Analysis 2022

The trace element composition of detrital magnetite grains recovered from six local streams around the Casino high-grade porphyry Cu-Au-Mo deposit, west-central Yukon, is compared with igneous and magmatic-hydrothermal mineralized unmineralized host rocks at deposit. Linear discriminant analysis 12 elements (Mg, Al, Ti, V, Mn, Co, Cr, Ni, Cu, Zn, Ga Ge) plots Ti versus Ni/Cr are used to discrim...

2016
Robert E. Danczak Steven B. Yabusaki Kenneth H. Williams Yilin Fang Chad Hobson Michael J. Wilkins

Citation: Danczak RE, Yabusaki SB, Williams KH, Fang Y, Hobson C and Wilkins MJ (2016) Snowmelt Induced Hydrologic Perturbations Drive Dynamic Microbiological and Geochemical Behaviors across a Shallow Riparian Aquifer. Front. Earth Sci. 4:57. doi: 10.3389/feart.2016.00057 Snowmelt Induced Hydrologic Perturbations Drive Dynamic Microbiological and Geochemical Behaviors across a Shallow Riparian...

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...

Journal: :Environmental science & technology 2006
M W Fields C E Bagwell S L Carroll T Yan X Liu D B Watson P M Jardine C S Criddle T C Hazen J Zhou

Few studies have demonstrated changes in community structure along a contaminant plume in terms of phylogenetic, functional, and geochemical changes, and such studies are essential to understand how a microbial ecosystem responds to perturbations. Clonal libraries of multiple genes (SSU rDNA, nirK, nirS, amoA, pmoA, and dsrAB) were analyzed from groundwater samples (n = 6) that varied in contam...

Journal: :The Science of the total environment 2009
Patrick Albéric Aurélie Vennink Sophie Cornu Hocine Bourennane Ary Bruand

While soil water composition has long been recognised as being related to soil type (characteristics of the horizons), the influence of structures resulting from agricultural activities (hedges, ditches, wheel ruts, etc) is still under discussion. This work was undertaken to show that a snapshot of spatial variability of the geochemical characteristics of soil water at the scale of a plot can i...

Journal: :international journal of mining and geo-engineering 0
samaneh safari shahrood university of technology mansour ziaii shahrood university of technology maliheh ghoorchi ferdowsi university of mashhad

singularity based on fractal and multifractal is a technique for detection of depletion and enrichment for geochemical exploration, while the index of vertical geochemical zonality (vz) of pb.zn/cu.ag is a practical method for exploration of blind porphyry copper mineralization. in this study, these methods are combined for recognition, delineation, and enrichment of vz in jebal- barez in the s...

2002
W. W. Shilts

and Vagners (1971, 1972) expressed this phenomenon elegantly by introducing the concept of "terminal mode" for the optimum grain size to which a mineral can be reduced, given the force and energy typically available in the glacial environment. Thus, hard, uncleaved or poorly cleaved minerals such as quartz, fcldspar, garnet, pyrite and magnetite dominate either the medium or the fine sand fract...

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