Granulite terrains have gently undulating topography, with charnockites and khondalites forming hillocks within low-lying areas comprising quartzofeldspathic gneisses (QFG). Petrographic, XRD and spectroscopic studies reveal that QFGs and charnockites show minimal clay mineral formation, indicating their resistance to chemical weathering. In contrast, khondalites weather progressively to form a variety of clay minerals, the proportion of which increases with elevation, ultimately stabilizing bauxite on hill-tops. Geochemical modelling indicates that this weathering pattern in khondalites can develop under open system conditions prevailing on hill tops and slopes, as rainwater is not retained within the system. This implies that the khondalite hills existed before bauxite formation. Since khondalite hills occur within more resistant but low-lying QFG, the present granulite terrain topography was not shaped by chemical weathering. Rather, mechanical weathering or neo-tectonic activity may be responsible for topography formation in stable granulite terrains.
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Bethke C M 2007 Geochemical and Biogeochemical Reaction Modeling; Cambridge University Press, New York.
Bhukte P and Chaddha M 2014 Geotechnical evaluation of eastern Ghats bauxite deposits of India; J. Geol. Soc. India 84 227–238.
Das S, Mehta B C, Singh R V and Srivastava S K 1994 Chemical Composition of rainwater over Bhubaneshwar, Orissa India; Mausam, Ind. J. Met. Hydro.l Geophys. (Q) 45 255–260.
Dasgupta S, Bose S, and Das K 2013 Tectonic evolution of the Eastern Ghats belt, India; Precamb. Res. 227 247–258.
Deb M and Joshi A 1984 Petrological studies on two East Coast bauxite deposits of India, and implications on their genesis; Sedim. Geol. 39 121–139.
Devaraju T and Khanadali S 1993 Lateritic bauxite profiles of South-western and southern India characteristics and tectonic significance; Curr. Sci. 64 919–921.
Farmer V C 1974 The infrared spectra of minerals (ed.) V C Farmer, London Mineralogical Society, 539p.
Frost R L, Kloprogge J T, Russell S C and Szetu J L 1999 Vibrational Spectroscopy and Dehydroxylation of Aluminum (Oxo)hydroxides: Gibbsite; Appl. Spectrosc. 43(4) 423–434.
Gupta S (2012) Strain localization, granulite formation and geodynamic setting of ‘hot orogens’: A case study from the Eastern Ghats Province, India; Geol. J. 47(23) 334–351.
Gupta S, Mohanty W K, Manda A and Misra S 2014 Ancient terrane boundaries as probable seismic hazards: A case studyfrom the northern boundary of the Eastern Ghats Belt, India; Geosci. Frontiers 5 17–24.
Holmes A 1978 Principles of Physical Geology; revised by Doris Holmes (3rd edn), Wiley, New York, 730p.
Landgraf A, Kuebler S, Hintersberger E and Stein S 2016 Active tectonics, earthquakes and palaeoseismicity in slowly deforming continents; In: Seismicity, Fault Rupture and Earthquake Hazards in Slowly Deforming Regions (eds) Landgraf A, Kuebler S, Hintersberger E and Stein S, Geol. Soc. London, Spec. Publ. 432, http://doi.org/10.1144/SP432.13.
Mitra S, Mitra K, Gupta S, Bhattacharya S, Chauhan P and Jain N 2016 Alteration and submergence of basalts in Kachchh, Gujrat, India: Implications for the role of the Deccan Traps in the India–Seychelles break-up; Geol. Soc. London Spec. Publ. 445 171–196.
Montgomery D R and Brandon M T 2002 Topographic controls on erosion rates in tectonically active mountain ranges; Earth Planet. Sci. Lett. 201 481–489.
Ramakrishnan M, Nanda J K and Augustine P F 1998 Geological evolution of the Proterozoic Eastern Ghat Mobile Belt; Geol. Surv. India Spec. Publ. 44 1–21.
Skinner B J and Porter S C 1995 The Dynamic Earth: An introduction to Physical Geology (3rd edn) John Wiley & Sons, Inc., 567p.
The main funding for this study was from the RTAC-BRNS project scheme, India (Sanction No. 35/14/12/2016-BRNS/35049) to SG. AM thanks IIT Kharagpur and the Ministry of Human Resource Development (MHRD), Department of Higher Education, New Delhi, India for providing the regular student assistantship. AM conveys her sincere gratitude to the Department of Geology and Geophysics, IIT Kharagpur for facilitating this study, and Prof. Kumar Biradha of the Department of Chemistry, IIT Kharagpur, for facilitating the XRD analysis. Additional support and discussion with Kaushik Mitra and Himela Moitra, Department of Geology & Geophysics, IIT Kharagpur, were also extremely useful. The paper has benefited greatly from the comments of the handling editor and two anonymous referees.
Communicated by N V Chalapathi Rao
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Maitra, A., Chatterjee, A., Keesari, T. et al. Forming topography in granulite terrains: Evaluating the role of chemical weathering. J Earth Syst Sci 129, 17 (2020). https://doi.org/10.1007/s12040-019-1293-4
- Granulite terrain
- chemical weathering