Abstract
Polyphase deformation and metamorphism of pelitic schists of Chorbaoli Formation of Sausar Group in and around Ramtek area, Nagpur district, Maharashtra, India has led to the development of garnet and sataurolite porphyroblasts in a predominantly quartz-mica matrix. Microstructural study of oriented thin sections of these rocks shows that garnet and staurolite have different growth histories and these porphyroblasts share a complex relationship with the matrix. Garnet shows at least two phases of growth — first intertectonic between D1 and D2 (pre-D2 phase) and then syn-tectonic to post-tectonic with respect to D2 deformation. Growth of later phase of garnet on the earlier (pre-D2) garnet grains has led to the discordance of quartz inclusion trails between core and rim portion of the same garnet grain. Staurolite develops only syn-D2 and shows close association with garnet of the later phase. The peak metamorphic temperature thus coincided with D2 deformation, which developed the dominant crenulation schistosity (S2), regionally persistent in the terrain. The metamorphic grade reached up to middle amphibolite facies in the study area, which is higher than the adjoining southern parts of Sausar Fold Belt.
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References
Barker A J 1994 Interpretation of porphyroblast inclusion trails: limitations imposed by growth kinetics and strain rates; J. Metamorph. Geol. 12 681–694.
Barker A J 1998 Introduction to metamorphic textures and microstructures; 2nd edn., Blackie, Glasgow.
Bell T H 1985 Deformation partitioning and porphyroblast rotation in metamorphic rocks: a radical reinterpretation; J. Metamorph. Geol. 3 109–118.
Bell T H and Rubenach M J 1983 Sequential porphyroblast growth and crenulation cleavage development during progressive deformation; Tectonophys. 92 171–194.
Bell T H and Chen A 2002 The development of spiral-shaped inclusion trails during multiple metamorphism and folding; J. Metamorph. Geol. 20 397–412
Bell T H and Johnson S E 1989 Porphyroblast inclusion trails: the key to orogenesis; J. Metamorph. Geol. 3 109–118.
Bell T H, Johnson S E, Davis B, Forde A, Hayward N and Wilkins C 1992a Porphyroblast inclusion-trail orientation data: eppure non son girate; J. Metamorph. Geol. 10 295–300.
Bell T H, Forde A and Hayward N 1992b Do smoothly curved, spiral-shaped inclusion trails signify porphyroblast rotation? Geology 20 59–62.
Bhowmik S K, Pal T, Roy A and Pant N C 1999 Evidence for Pre-Grenvillian high-pressure granulite metamorphism from the northern margin of the Sausar mobile belt in central India; J. Geol. Soc. India 53 385–399.
Bhowmik S K, Pal T, Roy A, Pant N C and Shome S 2000 Implication of Ramakona cordierite gneiss in the crustal evolution of Sausar mobile belt in Central India. Proc. Int. Seminar on Precambrian crust in Eastern and Central India, UNESCO-IUGS-IGCP-368; Geol. Surv. India Spec. Publ. 57 131–150.
Busa M D and Grey N H 1992 Rotated staurolite porphyroblasts in the Littleton Schist at Bolton, Connecticut, USA; J. Metamorph. Geol. 10 627–636.
Chattopadhyay A, Bandyopadhyay B K and Khan A S 2001 Geology and Structure of Sausar fold belt: A retrospection and some new thoughts; In: National Seminar on Recent Advances in the Field of Earth Sciences and their Implications in National Development; Geol. Surv. India Spec. Publ. 64 251–263.
Chattopadhyay A, Khan A S, Huin A K and Bandyopadhyay B K 2003a Reinterpretation of stratigraphy and structure of Sausar Group of rocks in Ramtek-Mansar-Kandri area, Maharashtra, Central India; J. Geol. Soc. India 61 75–89.
Chattopadhyay A, Huin A K and Khan A S 2003b Structural framework of Deolapar area, central India, and its implications for Proterozoic nappe tectonics; Gondwana. Res. 6 107–117.
Condie K C 1989 Plate Tectonics and Crustal Evolution. (3rd edn). Pergamon Press.
Hickey K A and Bell T H 1999 Behaviour of rigid ductile objects during deformation and metamorphism: a test using schists from the Bolton Syncline, Connecticut, USA; J. Metamorph. Geol. 17 211–228.
Jiang D and Williams P F 2004 Reference frame, angular momentum, and porphyroblast rotation; J. Struct. Geol. 26 2211–2224.
Johnson S E 1993a Unravelling the spirals: a serial thin section study and three-dimensional computer-aided reconstruction of spiral-shaped inclusion trails in garnet porphyroblasts; J. Metamorph. Geol. 11 621–634.
Johnson S E 1993b Testing models for the development of spiral-shaped inclusion trails in garnet porphyroblasts: to rotate or not to rotate, that is the question; J. Metamorph. Geol. 11 635–659.
Lippolt H J and Hautmann S 1994 Ar40/Ar39 ages of Precambrian manganese of ore minerals from Sweden, India and Morocco; Mineralium Deposita 30 246–256.
Narayanaswami S, Chakravarty S C, Vemban N A, Shukla K D, Subramaniam M R, Venkatesh V, Rao G V, Anandalwar M A and Nagrajiah R A 1963 The geology and manganese ore deposits of the manganese belt in Madhya Pradesh and adjoining parts of Maharashra. Part I: General Introduction; Bull. Geol. Surv. India A-22 (I).
Passchier C W and Trouw R A J 2005 Microtectonics. Springer-Verlag.
Passchier C W, Trouw R A J, Zwart H J and Vissers R L M 1992 Porphyroblast rotation: eppur si mouve? J. Metamorph. Geol. 10 283–294.
Powell D and Treagus J E 1970 Rotational fabrics in metamorphic minerals; Mineralogical Magazine 37 801–814.
Radhakrishna B P and Naqvi S M 1986 Precambrian continental crust and its evolution; J. Geol. 94 145–166.
Ramsay J G 1962 The geometry and mechanics of formation of “similar” type folds; J. Geol. 63 512–526.
Roy A and Prasad M H 2001 Precambrian of Central India: a possible tectonic model; Geol. Surv. India Spec. Publ. 64 177–197.
Roy A, Kagami H, Yoshida M, Roy A, Bandopadhyay B K, Chattopadhyay A, Khan A S, Huin A K and Pal T 2006 Rb-Sr and Sm-Nd dating of different metamorphic events from the Sausar Mobile Belt, central India: implications for Proterozoic crustal evolution; J. Asian Earth Sci. 26 61–76.
Sarkar S N, Trivedi J R and Gopalan K 1986 Rb-Sr whole rock and mineral isochron age of the Tirodi Gneiss, Sausar Group, Bhandara district, Maharashtra; J. Geol. Soc. India 27 30–37.
Schoneveld C 1979 The geometry and significance of inclusion patterns in syntectonic porphyroblasts. PhD thesis, Leiden State University.
Vernon R H 1975 Deformation and recrystallisation of a plagioclase grain; American Mineralogist 60 884–888.
Vernon R H 1976 Metamorphic processes. Allen and Unwin, London.
Vernon R H 1988 Microstructural evidence of rotation and non-rotation of mica porphyroblasts; J. Metamorph. Geol. 6 595–601.
Visser P and Mancktelow N S 1992 The rotation of garnet porphyroblasts around a single fold, Lukmanier Pass, Central Alps; J. Struct. Geol. 14 1193–1202.
Williams P F and Jiang D 1999 Rotating garnets; J. Metamorph. Geol. 17 367–378.
Yardley B W D 1989 An introduction to metamorphic petrology. Longman Earth Science Series, Wiley, New York.
Zwart H J 1962 On the determination of polymetamorphic mineral associations, and its application to the Bosost area (central Pyrenees); Geol. Rdsch 52 38–65.
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Chattopadhyay, A., Ghosh, N. Polyphase deformation and garnet growth in pelitic schists of Sausar Group in Ramtek area, Maharashtra, India: A study of porphyroblast-matrix relationship. J Earth Syst Sci 116, 423–432 (2007). https://doi.org/10.1007/s12040-007-0041-3
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DOI: https://doi.org/10.1007/s12040-007-0041-3