标题：Field characteristics, micro-morphology and GIS based evaluation of major element geochemistry of calcrete deposits of Vilathikulam and its surrounding villages, Thoothukudi District, Tamilnadu, India
期刊名称：International Research Journal of Environmental Sciences
电子版ISSN：2319-1414
出版年度：2017
卷号：6
期号：3
页码：11-19
语种：English
出版社：International Science Community Association
摘要：Calcretes is impure carbonate deposit formed with in the vadose zone by pedogenic leaching or phreatic zone by evapotranspiration of groundwater under the arid and semi-arid climatic conditions. It occurs in some places as duricrust outcrop centered on Vilathikulam region, Thoothukudi district of Tamilnadu. The general stratigraphic succession of the area profile is cited. The spatial collection of calcrete samples from the outcrops of various landscape setting were carried out. The Micromorphological characters of calcrete are in the form of gravel, nodular, lumby, massive, hardpan and chalky nature. The Micromorphological illustration reveals the micritic or microsparitic calcite precipitation which makes rimming, peloidal or colloform, veining, displacive and replacive structures. Major element geochemical analysis of calcrete indicates that CaO, MgO, SiO2, Fe2O3 and Al2O3 are in elevated concentration (>1%), whereas MnO, Na2O, K2O, TiO2 and P2O5 are in low level concentration (<1%). The GIS based major element geochemical iso-quality spatial contour maps illustrate the distributional quality of the area which helps to demarcate the suitability of the mining site of calcrete. Further, major element geochemistry delineates the geochemical environmental of the study area.
关键词：Authigenic;Macromorphology;Micromorphology;Micritic;Microsparitic;Major element geochemistry
