Deformation and metamorphism of a schistose terrane accreted with the Proterozoic Pakhal sequence of Godavari valley near Kothagudem, Andhra Pradesh
详细信息 查看全文
- 作者：Abhinaba Roy ; Kasturi Chakraborty…
- 关键词：Proterozoic sedimentary basins ; Pakhal ; Deformation ; Metamorphism ; Andhra Pradesh
- 刊名：Journal of the Geological Society of India
- 出版年：2015
- 出版时间：January 2015
- 年：2015
- 卷：85
- 期：1
- 页码：45-70
- 全文大小：5,623 KB
- 参考文献：Baker , A.J. (1994) Interpretation of porphyroblast inclusion trails: Limitations imposed by growth kinetics and strain rates. Jour. Metam. Geol., v.12, pp.681-94.View Article
Bell , T.H. (1985) Deformation partitioning and porphyroblast rotation in metamorphic rocks: a radical reinterpretation. Jour. Metam. Geol. v.3, pp.109-18.View Article
Bell , T.H. and Johnson , S.E. (1989) Porphyroblast inclusion trails: the key to orogenesis. Jour. Metam. Geol. v.7, pp.109-18.
Bell , T.H. and Rubenach , M.J. (1983) Sequential porphyroblast growth and crenulation cleavage development during progressive deformation. Tectonophysics, v.92, pp.171-94.View Article
Bell , T.H., Forde , A. and Hayward , N. (1992) Do smoothly curved, spiral-shaped inclusion trails signify porphyroblast rotation? Geology, v.20, pp.59-2.View Article
Bickle , M.J. and Archibald , N.J. (1984) Chloritoid and staurolite stability: implications for metamorphismin the Archaean Yilgarn Block, western Australia. Jour. Metam. Geol., v.2, pp.179-03.View Article
Butler , R.F., Gehrels , G.E., Mcclelland , W.C., May , S.R. and Klepacki , D. (1989) Discordant palaeomagnetic poles from the Canadian Coast Plutonic Complex: regional tilt rather than large scale displacement? Geology, v.17,pp.691-94.View Article
Chaudhuri , A.K. and Howard , J.D. (1985) Ramgundam Sandstone: a middle Proterozoic shoal-bar sequence. Jour. Sedimen. Petrol., v.55, pp.392-97.
Coney , P.J., Jones , D.L. and Monger , J.W.H. (1980) Cordilleran suspect terranes. Nature, v.288, pp.329-33.View Article
Connolly J.A.D. (2006). Computation of phase equilibria by linear programming: a tool for geodynamic modeling and its application to subduction zone decarbonation. Earth Planet. Sci. Lett., v.236, pp.524-41.View Article
Conrad , J.E., Hein , J.R., Chaudhuri , A.K., Patranabis -Deb , S., Mukhopadhyay , J., Deb , G.K. and Beukes , N.J. (2010) Constraints on the development of Proterozoic basins in Central India from 40Ar/39Ar analyses of authigenic glauconite minerals. Geol. Soc. Amer. Bull., v.123, pp.11-2.
Das , S., Nasipuri , P., Bhattacharya , A. and Swaminathan , S. (2008) The thrust-contact between the Eastern Ghats Belt and the adjoining Bastar craton (Eastern India): evidence from mafic granulites and tectonic implications. Precambrian Res., v.160, pp.70-5.View Article
Deb , G. (1999) Deformation style and evolution of the structures in the Penganga Group, Pranhita-Godavari valley, India. Geology of the Pranhita-Godavari Valley: Current status and future directions. Indian Stat. Inst., Calcutta. pp.14-6.
Ganguly , J. (1969). Chloritoid stability and related paragenesis: theory, experiment and application. Amer. Jour. Sci., v.267, pp.910-44.View Article
Ganguly , J. (1972). Staurolite stability and related parageneses: theory, experiments and applications. Journal of Petrology; v.13, pp.335-65.View Article
Ghosh , G. and Saha , D. (1999) Deformation of the Proterozoic Somanpalli Group, Pranhita-Godavari Velley–implication for a Mesoproterozoic basin inversion. Geology of the Pranhita- Godavari valley: Current Status and Future Directions: Indian Statistical Institute, Calcutta. pp.14-6.
Gibbons , W. (1990) Transcurrent ductile shear zones and the dispersal of the Avalon Superterrane. In: R.S. D’Lemos R.A. Strachan and C.G. Topley (Eds.), The Cadomian Orogeny Spec. Publ. Geol. Soc. London, v.51, pp.407-23.
Gibbons , W. (1994) Suspect Terranes. In: Paul L. Hancock (Ed.), Continental Deformation. Pergamon Press, U.K. pp.305-19.
Holland , T.J.B. and Powell , R. (1990) An enlarged and updated internally consistent thermodynamic dataset with uncertainties and corrections: the system K2O–Na2O–CaO–MgO–FeO–Fe2O3–Al2O3–TiO2–SiO2–C–H2–O2. Jour. Metam. Geol., v.8, pp.89-24.View Article
Hoscheck , G. (1967) Untersuchungen zum Stabilitatscbereich von Chlorotoid und Staurolith. Contributions to Mineralogy and Petrology, v.14, pp.123-62.View Article
Irwin , W.P. (1972) Terranes of the western Palaeozoic and Triassic belt in the southern Klamath Mountains, California, U.S. Geol. Surv. Prof. Pap.v. 800-C, pp.103-11.
Johnson , S.E. (1993) Unravelling the spirals: a serial thin-section study and three-dimensional computer–aided reconstruction of spiral-shaped inclusion trails in garnet porphyroblasts. Jour. Metam. Geol. v.11, pp.621-34.View Article
Kaila , K.L. and Tiwari , H.C. (1985) Structural trends in the Cuddapah basin from deep seismic soundings (DSS) and their tectonic implication. Tectonophysics, v.115, pp.69-6.View Article
King , W. (1881) Geology of the Pranhita-Godavari valley. Geol. Surv. India Mem., v.18, pp.151-11.
Mathur , S.M. (1982) Precambrian sedimentary sequences of India; their geochronology and correlations. Precambrian Res., v.18, pp.139-44.View Article
Mcwilliams , M.O. and Howell , D.G. (1982) Exotic terranes of western California. Nature, v. - 作者单位：Abhinaba Roy (1)
Kasturi Chakraborty (2)
Manas RoyChoudhury (3)
1. Department of Geology, Presidency University, Kolkata, India
2. CPL, CHQ, GSI, Kolkata, India
3. Natural Energy Resources, Mission IIIB, GSI, Kolkata, India - 刊物类别：Earth and Environmental Science
- 刊物主题：Geology
Geosciences
Geography
Mineralogy - 出版者：Springer India, co-published with Geological Society of India
- ISSN：0974-6889
文摘
From the recent research by several workers it is becoming evident that the geology, particularly the structure and metamorphism of the Proterozoic sedimentary basins are not simple, which can at times be compared with foldthrust belts. In the southern part of the Pranhita-Godavari (PG) basin in its close proximity with the Eastern Ghat Mobile belt (EGMB) in the east and Eastern Dharwar craton (EDC) in the west there is a supracrustal association exposed near Kothagudem in Andhra Pradesh, which was earlier referred in published literature as Mulug and Mallampalle Groups of lower Pakhal sequence. From the field and petrological studies we have attempted to enumerate here the deformation and metamorphic characteristics and the tectonic setup of this schistose unit. It is revealed from our studies that this lithotectonic unit represents a strongly deformed and metamorphosed deeper crustal supracrustal assemblage, which is in sharp contrast with the unmetamorphosed and weakly deformed true Pakhal sequence occurring in the western part of the area. In order to explain the spatial association of these two contrasting litho-tectonostratigraphic units we propose a westerly verging thrust model, supported by convincing structural and metamorphic evidences, whereby the schistose terrane is tectonically juxtaposed with the unmetamorphosed Pakhal sequence. Imprints of polyphase deformation and metamorphism could be recognized to document the complex history of the schistose terrane. At least three generation structures (D1, D2, D3) are identifiable in quartzite-metapelite-carbonate assemblages. D1 and D2 are quite pronounced and conspicuous by the development of respective planar and linear elements, while D3 is relatively mild in intensity. Development of different generations of folds (F1, F2, F3) and associated axial planar cleavage/ schistosity (S1, S2, S3) together with different types of fold interference patterns, demonstrated mainly in carbonate rocks, bear testimony to successive events of fold formation as a result of superposed deformations. The tectonic trend defined by N-S to NNESSW (approx.) elongation of the belt results from the combined effects of all the three deformations. The structural pattern indicate a possible combination of predominantly pure shear and subordinate simple shear transpressional type of tectonism accompanied by considerable E-W (approx.) tectonic shortening across the belt. The rocks show low to medium grade metamorphism with the characteric appearances of chlorite, biotite, andalusite, chloritoid, staurolite and garnet porphyroblasts in pelitic rocks. From a study on ‘Si-Se-tectonites in different mineral assemblages we have elucidated the history of deformation and metamorphic mineral growth in this assemblage. A variety of relationship exists between ‘Si-and ‘Se-demonstrating multi-stage growth of porphyroblasts, particularly of andalusite and staurolite, which took place during at least two deformational events. The important mineral assemblages include: (i) garnetbearing andalusite- biotite schist, (ii) garnet free andalusite-biotite schist, (iii) staurolite-andalusite-garnet-mica schist, (iv) andalusite-chloritoid-muscovite schist, and (v) garnet-chloritoid-chlorite-muscovite schist. The study establishes a prograde metamorphic evolution in each rock type followed by a retrograde history. But the relative timing of prograde and retrograde reactions with respect to successive phases of deformation varies widely.