Petrology of Charnockites from Madurai Block of Southern Granulite  Terrain, South India

G Indu; E  Shaji; R B Binojkumar; M Santosh; T Tsunogae

doi:10.48165/

Authors

G Indu Department of Geology, University of Kerala, Kariavattom campus, Thiruvananthapuram, Kerala695581, India.
E Shaji Department of Geology, University of Kerala, Kariavattom campus, Thiruvananthapuram, Kerala695581, India.
R B Binojkumar Department of Geology, University of Kerala, Kariavattom campus, Thiruvananthapuram, Kerala695581, India.
M Santosh School of Earth Sciences and Resources, China University of Geosciences Beijing, 29 Xueyuan Road, Beijing 100083, China
T Tsunogae Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki 305-8572, Japan

DOI:

https://doi.org/10.48165/

Keywords:

Charnockite, SGT, Madurai Block, Geochemistry, Enderbite

Abstract

Charnockites are the most extensively studied rocks in the Southern Granulite Terrain (SGT). Charnockites are popularly known as hypersthene-bearing granite. Charnockite occurs as massive, foliated and incipient varieties in different crustal blocks of SGT. This paper presents the petrology and geochemistry of charnockite from Madurai Block. The charnockite (enderbite) studied from the Madurai Block is a medium grained rock with a mineralogy of 30-40% of quartz, 25-35% of feldspar, 15%-20% of ferromagnesian minerals (2-5% orthopyroxene, 2%-3% hornblende and 2%-3% biotite). Accessory minerals include Fe-Ti oxides (dominantly ilmenite), apatite, and zircon. The charnockites are dioritic to granitic in composition with high Al2O3 content and display both ferroan and magnesian characters. The REE plots of charnockites show high concentration of light rare earth elements (LREEs) and relatively low contents of heavy rare earth elements (HREEs), with significant LREE/HREE fractionation. They also show positive Eu anomalies or lack of Eu anomalies. Ba enrichment is the important characteristic of these charnockites with distinct Nb, Ta, and Ti depletion in mantle-normalized primitive mantle multi-elements diagrams, which has been considered to be one of the potential geochemical imprints of continental margin magmatism in a subduction-related environment.

Downloads

Download data is not yet available.

References

Amaldev, T., Santosh, M., Li, T., Baiju, K.R., Tsunogae, T., Satyanarayanan, M., 2016. Mesoarchean convergent margin processes and crustal evolution: petrologic, geochemical and zircon U-Pb and Lu-Hf data from the Mercara Suture Zone, southern India. Gondwana Res. 37, 182-204.

Barker, F., 1979. Trondhjemite: definition, environment and hypotheses of origin. In: Barker,F. (Ed.), Trondhjemites, Dacites

and Related Rocks. Elsevier, Amsterdam, pp. 1–12

Chowdhury, P. and Chakraborty, S., 2019. Slow cooling at high temperatures of high P mafic granulites from the Southern Granulite Terrain, India: Implications for the presence and style of plate tectonics near the Archean-Proterozoic boundary. Journal of Petrology.

Clark, C., Collins, A.S., Kinny, P.D., Timms, N.E., Chetty, T.R.K., 2009. SHRIMP U–Pb age constraints on the age of charnockite magmatism and metamorphism in the Salem Block, southern India. Gondwana Res. 16, 27-36.

Collins, A.S., Clark, C. and Plavsa, D., 2014. Peninsular India in Gondwana: the tectonothermal evolution of the Southern Granulite Terrain and its Gondwana counterparts. Gondwana Research, 25(1), pp.190-2035 Das, R. and Rai, S.S., 2019. Redefining Dharwar Craton-Southern Granulite Terrain boundary in south India from new seismological constraints. Precambrian Research, p.105394.

Das, R. and Rai, S.S., 2019. Redefining Dharwar Craton-Southern granulite terrain boundary in south India from new seismological constraints. Precambrian Research, 332, p.105394.Frost, B.R., Arculus, R.J., Barnes, C.G., Collins, W.J., Ellis, D.J., Frost, C.D., 2001. A geochemical classification of granitic rocks. J. Petrol. 42, 2033–2048.

Frost, B.R., Arculus, R.J., Barnes, C.G., Collins, W.J., Ellis, D.J., Frost, C.D., 2001. A geochemical classification of granitic rocks. J. Petrol. 42, 2033–2048.

Holland, Thomas Henry. The charnockite series: a group of archæan hypersthenic rocks in peninsular india. Vol. 28, no. 2. Sold at the Office of the Geological Survey, 1900.

Li, S. S., Santosh, M., Ganguly, S., Thanooja, P. V., Sajeev, K., Pahari, A and Manikyamba, C., 2018. Neoarchean microblock amalgamation in southern India: Evidence from the Nallamalai Suture Zone. Precambrian Research, 314, 1–27.

Plavsa, D., Collins, A.S., Payne, J.L., Foden, J., Clark, C., Santosh, M., 2014. Detrital zircons in basement metasedimentary protoliths unveil the

origins of sourthern India. Geol. Soc. Am. Bull. 126, 791–812.

Praveen, M.N., Santosh,M., Yang, Q.Y., Zhang, Z.C., Huang, H., Singanenjam, S., Sajinkumar, K.S., 2014. Zircon U–Pb geochronology and Hf isotope of felsic volcanics from Attappadi, southern India: implications for Neoarchean convergent margin tectonics. Gondwana Res. 26, 907– 924.125.

Rajesh, H.M., Santosh, M., 2012. Charnockites and charnockites. Geosci. Front. 3, 737–744.

Samuel, V.O., Santosh, M., Liu, S.W., Wang, W., Sajeev, K., 2014. Neoarchean continent growth through arc magmatism in the Nilgiri Block, southern India. Precambrian Res. 245, 146–173.

Santosh, M., Maruyama, S., Sato, K., 2009. Anatomy of a Cambrian suture in Gondwana: Pacific-type orogeny in the southern India? Gondwana Res. 16, 321– 341.

Santosh, M., Yang, Q.Y., Shaji, E., Tsunogae, T., Ram Mohan, M., Satyanarayanan, M., 2015. An exotic Mesoarchean microcontinent: the Coorg Block, southern India. Gondwana Res. 27, 165–195.

Santosh, M., Yang, Q.Y., Shaji, E., Ram Mohan, M., Tsunogae, T., Satyanarayanan, M., 2016. Oldest rocks from Peninsular India: evidence for Hadean to Neoarchean crustal evolution. Gondwana Res. 29, 105– 135.

Santosh, M., Chao-Nan Hu, Xiao-Fang He, Shan-Shan Li, T. Tsunogae, E. Shaji, and G. Indu., 2017. Neoproterozoic arc magmatism in the southern Madurai block, India: Subduction, relamination, continental outbuilding, and the growth of Gondwana. Gondwana Research. 45, 1-42.

Santosh, M. (2020). The Southern Granulite Terrane: A synopsis. Episodes Journal of 1022 International Geoscience, 43(1), 109-123.

Shaji, E., Santosh, M., He, X.F., Fan, H.R., DhanilDev, S.G., Yang, K.F., Thangal, M.K., Pradeepkumar, A.P., 2014. Convergent margin processes during Archean–Proterozoic transition in southern India: geochemistry and zircon U–Pb geochronology of gold bearing amphibolites, associated metagabbros, and TTG gneisses from Nilambur. Precambrian Res. 250, 68–96.

Subramaniam, A.P., 1960. Petrology of the charnockite suite of rocks from the type area around St. Thomas Mount and Pallavaram, near Madras City, India. Rep, 21, pp.394-403.

Wilson, B.M., 1989. Igneous Petrogenesis: A Global Tectonic Approach. Springer. 22. Yang, Q.Y., Santosh, M., Pradeepkumar,

A.P., Shaji, E., Prasanth, R.S., Dhanil Dev, A.G., 2015. Crustal evolution in the western margin of the Nilgiri Block,

southern India: insights from zircon U–Pb and Lu–Hf data on Neoarchean magmatic suite. J. Asian Earth Sci.113, 766–777.

Yellappa, T. and Rao, J.M., 2018. Geochemical characteristics of Proterozoic granite magmatism from Southern Granulite Terrain, India: Implications for Gondwana. Journal of Earth System Science, 127(2), p.22.