Geochemistry of biotites and host granitoid plutons from the Proterozoic Mahakoshal Belt, central India tectonic zone: implication for nature and tectonic setting of magmatism

2015 ◽  
Vol 57 (11-12) ◽  
pp. 1686-1706 ◽  
Author(s):  
Sita Bora ◽  
Santosh Kumar
Keyword(s):  
Tectonic Setting ◽  
Central India ◽  
Tectonic Zone

Mineral chemistry, P-T pseudosection and in-situ U-Th-Pbtotal monazite geochronology of Banded Iron Formation from Bundelkhand craton North-Central India, and its geodynamic significance

2021 ◽  
Author(s):  
Mohd Baqar Raza ◽  
Pritam Nasipuri ◽  
Hifzurrahman
Keyword(s):  
Central India ◽  
Mineral Chemistry ◽  
Iron Formation ◽  
Age Group ◽  
Banded Iron Formation ◽  
Tectonic Zone ◽  
Third Age ◽  
The Third ◽  
Hydrothermal Activities

<p>The Banded Iron Formation (BIF) in Bundelkhand craton (BuC) occurred as supracrustals associated with TTG’s, amphibolites, calcsilicate rocks, and quartzite within the east-west trending Bundelkhand tectonic zone (BTZ). The BIFs near Mauranipur do not show any prominent iron-rich and silica-rich layer band and are composed of garnet, amphibole, quartz, and magnetite. The volumetrically dominant monoclinic-amphiboles are grunerite in composition. X<sub>Mg</sub> of grunerite varies between 0.39-0.37. The garnets are Mn-rich, the X<sub>Spss</sub> of garnet ranges from 0.26-0.20, X<sub>Pyp</sub> and X<sub>Grs </sub>vary between 0.10-0.06 and 0.07-0.05, respectively. P-T pseudosection analysis indicates that by destabilizing iron-silicate hydroxide phases through a series of dehydration and decarbonation reactions, amphibole and garnet stabilized in BIF at temperature 400-450°C and pressure 0.1-0.2 GPa.</p><p>Massive type BIFs have monazite grains that vary from 10 to 50 µm in size, yield three distinct U-Th-Pb<sub>total</sub> age clusters. 10-20 µm sized monazite grains yield the oldest age, 3098±95 Ma. 2478±37 Ma average age is obtained from the second group, which is relatively larger and volumetrically predominant. The third age group of Monaiztes gives an age of 2088±110 Ma. ~3100 Ma monazite suggests the older supracrustal rocks of Bundelkhand craton, similar to those obtained from Singhbhum and the Dharwar craton. The 2478±37 Ma age is constrained as the timing of metamorphism and stabilization of BuC. The third age group, 2088±110 Ma probably associated with renewed hydrothermal activities, leading to rifting and emplacement of mafic dykes in BuC.</p>

∼2.1 Ga intraoceanic magmatism in the Central India Tectonic Zone: Constraints from the petrogenesis of ferropicrites in the Mahakoshal supracrustal belt

2017 ◽  
Vol 302 ◽  
pp. 1-17 ◽  
Author(s):  
Tarun C. Khanna ◽  
D.V. Subba Rao ◽  
Michael Bizimis ◽  
M. Satyanarayanan ◽  
A. Keshav Krishna ◽  
...  
Keyword(s):  
Central India ◽  
Tectonic Zone ◽  
Supracrustal Belt

Geochemistry of metasedimentary rocks of the Proterozoic Xingxingxia complex: implications for provenance and tectonic setting of the eastern segment of the Central Tianshan Tectonic Zone, northwestern China

2005 ◽  
Vol 42 (3) ◽  
pp. 287-306 ◽  
Author(s):  
Qiugen Li ◽  
Shuwen Liu ◽  
Baofu Han ◽  
Jian Zhang ◽  
Zhuyin Chu
Keyword(s):  
Tectonic Setting ◽  
Active Continental Margin ◽  
Northwestern China ◽  
Geochemical Data ◽  
Isotopic Study ◽  
Tectonic Zone ◽  
Elemental Ratios ◽  
Chemical Index ◽  
Eastern Segment ◽  
Chemical Index Of Alteration

The eastern segment of the Central Tianshan Tectonic Zone in northwestern China includes the Proterozoic metasedimentary Xingxingxia complex. Because these rocks have been extensively deformed and metamorphosed to greenschist or amphibolite facies, a geochemical and Nd isotopic study was undertaken to constrain their provenance and tectonic setting, as well as to evaluate the effects of weathering and sedimentary processes on the source rock signature. Major- and trace-element data indicate that these samples are characterized by negative Eu anomalies, low chemical index of alteration values, and high index of compositional variability values. Chemical index of alteration values and the plot of molecular proportions Al2O3–(CaO* + Na2O)–K2O suggest low degrees of weathering of the source. They are compositionally immature and poorly sorted. Geochemical data and immobile elemental ratios, for example Al2O3/TiO2, Cr/Th, Eu/Eu* and (La/Yb)n, indicate that the clastic materials were derived predominantly from felsic sources. Sedimentary tectonic discrimination diagrams demonstrate that most of the samples of the Xingxingxia complex were deposited on an active continental margin or continental island-arc setting. Rare-earth element distributions, εNd(t) values (calculated at 1.20 Ga, varying from –3.00 to +6.1), TDM model ages (ranging from 1.30 to 2.30), and t – εNd(t) plot, indicate that sediments of the Proterozoic Xingxingxia complex were derived from varying degrees of mixing between Paleoproterozoic crust and juvenile materials with the former predominating. There is an increased flux of juvenile materials from Weiya in the east through Dikar to Kumishi. The secondary juvenile source may be 1.2 Ga arc-magma materials.

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