Trace, Rare-Earth Elements and C, O Isotope Systematics of Carbonate Rocks of Proterozoic Bhima Group, Eastern Dharwar Craton, India: Implications for the Source of Dissolved Components, Redox Condition and Biogeochemical Cycling of Mesoproterozoic Ocean

AbstractIn the Late Archean north-trending Closepet pluton, trains of euhedral K-feldspar phenocrysts and matrix-supported idiomorphic K-feldspar crystals in the central part of the pluton define oblique-to-pluton margin steep-dipping east/ENE-trending magmatic fabrics. The magmatic fabric is defined by phenocryst-rich and phenocryst-poor layers, with the euhedral porphyries continuous across the layers. The fabrics are near-orthogonal to the gently-dipping gneissic layers in the host gneisses. The fabrics curve adjacent to locally-developed north/NNE-trending melt-hosted dislocations parallel to the axial planes of horizontal/gently-plunging north-trending upright folds in the host gneisses. In the pluton interior, both fabrics in the intrusives formed at supra-solidus conditions, although the volume fraction of melts diminished drastically due to cooling/melt expulsion. At the pluton margin, the north-trending fabric is penetrative and post-dates magma solidification. Within the pluton, the major element oxides, rare earth elements, anorthite contents in plagioclase, and (Mg/Fe + Mg) ratios in biotite decrease with increasing SiO2 from phenocryst-rich (up to 75% by volume) granodiorite to phenocryst-poor (<15 vol%) granite that broadly correspond to minimum melt composition. The chemical-mineralogical variations in the pluton is attributed to deformation-driven ascent of magma with heterogeneous crystal content, ascending at variable velocities (highest in crystal-poor magma) along oblique-to-pluton margin east/ENE-trending extensional fractures induced by dextral shearing.

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Geochemistry of rare earth elements in carbonate rocks of the Mirga Mir Formation (Lower Triassic), Kurdistan Region, Iraq

Arabian Journal of Geosciences ◽

10.1007/s12517-015-2148-1 ◽

2016 ◽

Vol 9 (4) ◽

Cited By ~ 1

Author(s):

Faraj H. Tobia ◽

Ahmid M. Aqrawi

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Carbonate Rocks ◽

Lower Triassic ◽

Kurdistan Region

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Tauride Carbonate Platform Bauxite Deposits (Turkey) as an Alternative Source for Gallium

10.5194/egusphere-egu21-11122 ◽

2021 ◽

Author(s):

Hatice Nur Bayram ◽

Ali Erdem Bakkalbasi ◽

Zeynep Doner ◽

Ali Tugcan Unluer ◽

Huseyın Kocaturk ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Carbonate Rocks ◽

Carbonate Platform ◽

Primary Source ◽

Geochemical Data ◽

Strong Positive Correlation ◽

Alternative Source ◽

Positive Correlation ◽

Bayer Liquor

Mediterranean type karstic bauxite deposits are considered as the primary source for aluminum (Al) production in Europe. During the Al production, Gallium (Ga) is extracted from the so called Bayer-liquor during the processing of bauxite to alumina. Ga, a rare metal, is widely used in modern chemistry and electronic industry. During the past decades, the worldwide demand for Ga has been continuously increasing. In Turkey, karstic bauxite deposits are generally found with shallow marine carbonate rocks which were deposited during Mesozoic period and located in Tauride Carbonate platform. Most of these karstic bauxite deposits can be hosted considerable Ga enrichments, with other immobile elements such as rare earth elements (REE), titanium (Ti), lithium (Li), and iron (Fe). This work focuses on the revealing of the potential Ga enrichments in bauxides from different deposits of Turkey (Morta&#351;-Do&#287;ankuzu, Konya; K&#252;&#231;&#252;kkora&#351;, Karaman; Ac&#305;elma-Yo&#287;unoluk, Kahramanmara&#351; bauxite deposits). Geochemical data of major and trace elements of studied bauxite deposits show that these deposits have significant Ga enrichments (up to 72.6 ppm), as well as the REE (up to 580 ppm), Ti (up to 1.8%), and Li (up to 428 ppm) enrichments. In addition, the Ga enrichments show strong positive correlation with heavy rare earth elements (HREE) and moderate positive correlation with Al, Fe, Ti, Li and Sn elements. In this context, it can be concluded that the most probable source for Ga is rock forming aluminosilicates of the source rock due to the substitution with Al3+ and Fe3+. During weathering process Ga exhibiting immobile behavior much like Al and Fe. Gallium is than incorporated into Al-bearing phases and thus enriched in the bauxite. Presence of Li content can be also interpreted as a contribution from micaceous source such as meta-carbonate rocks of Tauride platform. Moreover, geochemical association between Ga, Ti, Li, tin (Sn) and HREE can be explained by the redox and pH conditions causing other ions seperated from shallow environments.

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