Contrasting mineralogy and strain partitioning across N-S oriented Sitampundi - Kanjamalai Shear in Sitampundi Anorthosite Layered Complex

  • Harish M.K Department of Geology, Government Arts College, Salem-636007, Tamil Nadu, India.
  • Rahul J Department of Geology, Government Arts College, Salem-636007, Tamil Nadu, India.
  • Thirukumaran V Department of Geology, Government Arts College, Salem-636007, Tamil Nadu, India.
Keywords: Sitampundi Anorthosite Layered Complex (SALC), Sitampundi – Kanjamalai Shear, Strain analysis, Clinozoisites, Zoning, Thirumanimuthar river


Sitampundi Anorthosite Layered Complex (SALC) is a complexly folded and metamorphosed terrain that shows different metamorphic grade separated by a regional linear divide. In the north-eastern part of the complex, the anorthosites contain green-colored clinozoisites that are strikingly absent in the western part of the limb. Based on the presence of the clinozoisites, the entire SALC can be divided into two zones. The Sitampundi-Kanjamalai shear zone (SKSZ) separates mega crystals of clinozoite bearing anorthosites from clinozoisite free anorthosites. To add furthermore, strain analysis of different samples of anorthosite on either side of the zones was conducted by employing Flinn method. In general, anorthosites fall into the flattening field. The clinozoisite free anorthosites are more flattening and clinozoisite bearing anorthosites exhibit a slight difference in their strain ratio, ie., it is comparatively less flattening.  Geochemistry of clinozoisites was studied using EPMA & XRD methods. The percentage of oxides obtained from EPMA coincides with that of epidote. But, XRD confirms the mineral to be clinozoisite indicating the transition phase of epidote to clinozoisite. Zoning has had occurred in clinozoisites with aluminium oxide rich core and FeO rich rim. This could be related to a retrogression corresponding to a shearing event.


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A.P. Subramaniam, Mineralogy and Petrology of The Sittampundi Complex, Salem District, Madras State, India, Geological Society of America Bulletin, 67 (1956) 317-379.

C.E. Nehru, Geology and Petrochemistry of the Anorthite-Gneiss And Associated Rocks Of Sittampundi, Salem District, Journal of the Madras University, 2(1955) 178-188.

P.R.J. Naidu, A Layered Complex in Sittampundi, Madras State, India, Mineralogical Society of America, 1 (1964) 116-123.

S. Ramadurai, M. Sankaran, N.T.A. Se Lva, B.F. Windley, The Stratigraphy and Structure of The Sittampundi Complex, Tamil Nadu, India, Journal of Geological Society of India, 16 (1975) 409-414.

A.S. Janardhanan, B.E. Leake, The Origin of The Meta Anorthositic Gabbros and Garnetiferous Granulites of The Sittampundi Complex, Madras, India, Journal of the Geological Society of India, 16 (1975) 391-408.

Y.J. Bhaskar Rao, T.R.K. Chetty, Janardhan, K. Gopalan, (1996) Sm-Nd and Rb-Sr Ages and Pt History of The Archean Sittampundi and Bhavani Layered Meta-Anorthosite Complex in Cauvery Shear Zone, South India, Contributions to Mineralogy and Petrology, 125, (1996) 237 – 250.

J.G. Ghosh, M.J. De Wil, R.E. Zartman, (2004) Age and Tectonic Evolution of Neoproterozoic Ductile Shear Zone in The Southern Granulite Terrain of India, With Implications for Gondwana Studies, Tectonics, 23 (2004) 1961–197.

M. Behera, B.D. Waele, V. Thirukumaran, K. Sundaralingam, S. Narayanan, B. Sivalingam, K. Pande, T.K. Biswal, (2019) Kinematics, strain pattern and geochronology of the Salem-Attur shear zone: Tectonic implications for the multiple sheared Salem-Namakkal blocks of the Southern Granulite terrane, India, Precambrian Research, 324 (2019) 32-61.

P. Sengupta, M.M. Raith, E. Kooijman, M. Talukdar, P. Chowdhury, S. Sanyal, K. Mezger, D. Mukhopadhyay, (2015) Provenance, Timing of Sedimentation And Metamorphism Of Metasedimentary Rock Suites From The Southern Granulite Terrane, India, Geological Society, London, Memoirs, 43 (2015) 297–308.

K. Sajeeva, B.F. Windley, J.A.D. Connolly, Y. Kon, Retrogressed Eclogite (20 Kbar, 1020 ◦C) From the Neoproterozoic Palghat–Cauvery Suture Zone, Southern India, Precambrian Research, 171 (2009) 23–36.

M.M. Raith, C. Srikantappa, D. Buhl, H. Koehler, The Nilgiri Enderbites, South India: Nature and Age Constraints On Protolith Formation, High-Grade Metamorphism And Cooling History, Precambrian Research, 98 (1999) 129–150.

M. Rammohan, Satyanarayanan M, Santosh M, Paul J. Sylvester, Miketubrett, Rebecca Lam, Neoarchean Supra-Subduction Zone Arc Magmatism in Southern India: Geochemistry, Zircon U-Pb Geochronology and Hf Isotopes of The Sittampundi Anorthosite Complex, International Association for Gondwana Research, 23 (2013) 539-557.

S. Brandt, M. M. Raith, V. Schenk, P. Sengupta, C. Srikantappa, A. Gerdes, (2014) Crustal Evolution of The Southern Granulite Terrane, South India: New Geochronological and Geochemical Data for Felsic Orthogneisses and Granites, Precambrian Research, 246 (2014) 91–122.

B. F. Windley, T. A. Selvan, Anorthosites and Associated Rocks, Of Tamil Nadu, Southern India, Journal of Geological Society of India, 16 (1975) 209-215.

V. Thirukumaran, V. Sowmya, S. Boopathi, R. Mythili, T.K. Biswal, K. Sundaralingam, Strain Pattern Analysis of Mylonites from Sitampundi-Kanjamalai Shear Zone, Thiruchengode, South India, 1 (2019) 25-34.

D. Flinn, On Folding During Three-Dimensional Progressive Deformation, Quarterly Journal of the Geological Society, 118 (1962) 385-428.

D. Elliott, (1972) Deformation Paths in Structural Geology GSA Bulletin 83 (1972) 2621-2638.

Ivar B. Ramberg, Scott B. Smithson, Gridded Fault Patterns in A Late Cenozoic and A Paleozoic Continental Rift, Geology, 3 (1975) 201-205.

R.H. Grapes, P.W.O. Hoskin, Epidote Group Minerals in Low-Medium Pressure Metamorphic Terranes, Reviews in Mineralogy and Geochemistry, 56 (2004) 301-345.

Gerhard Franz, A. Liebscher Physical and Chemical Properties of The Epidote Minerals–An Introduction, Reviews in Mineralogy & Geochemistry, 56 (2004) 1-82.

Gerhard Franz, J. Selverstone, An Empirical Phase Diagram for the Clinozoisite-Zoisite Transformation in The System Ca2al3si3o12(Oh)-Ca2al2fe 3+Si3o12(Oh), American Mineralogist, 77 (1992) 631-642.

W.A. Deer, R.A. Howie, J. Zussman, (1992) An Introduction to the Rock-Forming Minerals, 2nd edition, (Longman Scientific & Technical), London, UK.

Shreya Karmakar, Subham Mukherjee, Sanjoy Sanyal, Pulak Sengupta, (2017) Origin of Peraluminous Minerals (Corundum, Spinel, And Sapphirine) In A Highly Calcic Anorthosite from The Sittampundi Layered Complex, Tamil Nadu, India, Contributions to Mineralogy and Petrology, 172 (2017)

F. J. Turner, (1947) Mineralogical and Structural Evolution of The Metamorphic Rocks, The Geological Society of America, New york.

How to Cite
M.K, H.; J, R.; V, T. Contrasting Mineralogy and Strain Partitioning across N-S Oriented Sitampundi - Kanjamalai Shear in Sitampundi Anorthosite Layered Complex. ijceae 2021, 3, 67-80.

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