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Geochemical, Sr and Nd isotopic studies on the Kalva Rangan Durga Quartzites of the Shimoga greenstone belt: Implications on weathering of Dharwarian continental crust
https://repo.qst.go.jp/records/80262
https://repo.qst.go.jp/records/80262e577a1d0-4d53-4475-9529-eaa446f4649f
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2020-08-03 | |||||
| タイトル | ||||||
| タイトル | Geochemical, Sr and Nd isotopic studies on the Kalva Rangan Durga Quartzites of the Shimoga greenstone belt: Implications on weathering of Dharwarian continental crust | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | journal article | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Murugan, Rajamanickam
× Murugan, Rajamanickam× Srinivasan, Balakrishnan× K Tripathi, Jayant× Murugan, Rajamanickam |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | The Mesoarchean Kalva Rangan Durga Formation of the Shimoga greenstone belt in the western Dharwar Craton consists of orthoquartzite, ferruginous phyllite, banded ferruginous chert, and conglomerates. Thick beds of orthoquartzites of this formation are well exposed in Kalva Rangan Durga ridge, trending northeast to southwest for about 9 km, in the southwest part of the Honnali Dome. Quartzites are fine-grained in nature and mostly composed of quartz grains and fuchsite mica. In the present study, we have collected quartzite samples and carried out geochemical, Sr, and Nd isotope analyses to decipher their paleo-weathering conditions, provenance characteristics, and possible tectonic setting of deposition. Geochemical data indicate they are arkose to subarkose in nature. Moderate to intense chemical weathering of the source rocks of these quartzites during the Mesoarchean is suggested based on various weathering indices and ternary plots. Enriched LREE and flat to variably fractionated HREE patterns with negative Eu anomalies of quartzites indicate that they were mainly derived by weathering of tonalities, trondhjemite, and granodiorites (TTG) gneisses and granites. The relatively high concentration of Cr with variable Th/Sc and high Cr/Th ratios indicate both felsic and mafic sources for quartzites. Initial εNd values (t = 3.0 Ga) of quartzites range from −3.04 to +1.24 which further support their derivation from both older evolved continental crustal and juvenile sources. The presence of symmetrical ripple marks on the surface of quartzite indicates a shallow marine environment. | |||||
| 書誌情報 |
Geological Journal 巻 55, 号 6, p. 4830-4844, 発行日 2022-01 |
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| 出版者 | ||||||
| 出版者 | John Wiley & Sons Ltd | |||||
| ISSN | ||||||
| 収録物識別子タイプ | ISSN | |||||
| 収録物識別子 | 1099-1034 | |||||
