DOI: 10.1007/s00531-015-1229-4
Scopus记录号: 2-s2.0-84939609128
论文题名: Radioelemental, petrological and geochemical characterization of the Bundelkhand craton, central India: implication in the Archaean geodynamic evolution
作者: Ray L. ; Nagaraju P. ; Singh S.P. ; Ravi G. ; Roy S.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2016
卷: 105, 期: 4 起始页码: 1087
结束页码: 1107
语种: 英语
英文关键词: Accessory radioactive minerals
; Archaean granitoids
; Bundelkhand craton
; Central India
; Geochemical data
; Radioelemental abundances
; TTG gneisses
Scopus关键词: accessory mineral
; Archean
; craton
; geochemistry
; geodynamics
; gneiss
; granitoid
; greenstone belt
; petrology
; Bundelkhand
; India
英文摘要: We have carried out radioelemental (232Th, 238U, 40K), petrological and geochemical analyses on granitoids and gneisses covering major rock formations of the Bundelkhand craton, central India. Our data reveal that above characteristics are distinct among granitoids (i.e. pink, biotite and grey granitoids) and gneisses (i.e. potassic and sodic types). Pink granitoid is K-feldspar-rich and meta-aluminous to per-aluminous in character. Biotite granitoid is meta-aluminous in character. Grey granitoid is rich in Na-feldspar and mafic minerals, granodiorite to diorite in composition and meta-aluminous in character. Among these granitoids, radioelements (Th, U, K) are highest in pink granitoid (45.0 ± 21.7 ppm, 7.2 ± 3.4 ppm, 4.2 ± 0.4 %), intermediate in biotite granitoid (44.5 ± 28.2 ppm, 5.4 ± 2.8 ppm, 3.4 ± 0.7 %) and lowest in grey granitoid (17.7 ± 4.3 ppm, 4.4 ± 0.6 ppm, 3.0 ± 0.4 %). Among gneisses, potassic-type gneisses have higher radioelements (11.8 ± 5.3 ppm, 3.1 ± 1.2 ppm, 2.0 ± 0.5 %) than the sodic-type gneisses (5.6 ± 2.8 ppm, 1.3 ± 0.5 ppm, 1.4 ± 0.7 %). Moreover, the pink granitoid and the biotite granitoid have higher Th/U (6 and 8, respectively) compared to the grey granitoid (Th/U: 4), implying enrichment of Th in pink and biotite granitoids relative to grey granitoid. K/U among pink, biotite and grey granitoids shows little variation (0.6 × 104, 0.6 × 104, 0.7 × 104, respectively), indicating relatively similar increase in K and U. Therefore, mineralogical and petrological data along with radioelemental ratios suggest that radioelemental variations in these lithounits are mainly related to abundances of the radioactive minerals that have formed by the fractionation of LILE from different magma sources. Based on present data, the craton can be divided into three distinct zones that can be correlated with its evolution in time and space. The central part, where gneisses are associated with metavolcanics of greenstone belt, is characterized by lowest radioelements and is the oldest component. The southern part, dominated by pink granitoid, is characterized by highest radioelements and is the youngest part. The northern part, dominated by grey and biotite granitoid, is characterized by moderate radioelements. © 2015, Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939609128&doi=10.1007%2fs00531-015-1229-4&partnerID=40&md5=a12579e104a5149a5d423c41329d591f
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70158
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: CSIR-National Geophysical Research Institute, Hyderabad, India; Department of Geology, Bundelkhand University, Jhansi, India
Recommended Citation:
Ray L.,Nagaraju P.,Singh S.P.,et al. Radioelemental, petrological and geochemical characterization of the Bundelkhand craton, central India: implication in the Archaean geodynamic evolution[J]. International Journal of Earth Sciences,2016-01-01,105(4)