Precambrian Research 246 (2014) 321–333 Contents lists available at ScienceDirect Precambrian Research jo ur nal homep ag e: www.elsevier.com/locate/precamres Palaeoproterozoic fluvio-aeolian deposits from the lower Gulcheru Formation, Cuddapah Basin, India Himadri Basu a,∗ , R. Suryanarayana Sastry b,1 , Kiran Kumar Achar a,2 , K. Umamaheswar a,3 , Pratap Singh Parihar a,4 a Atomic Minerals Directorate for Exploration and Research, 1-10-153-156, S.P. Road, Begumpet, Hyderabad 500 016, India b Department of Applied Geochemistry, Osmania University, Hyderabad 500 007, India a r t i c l e i n f o Article history: Received 22 July 2013 Received in revised form 5 February 2014 Accepted 13 March 2014 Available online 21 March 2014 Keywords: Fluvio-aeolian Warm and semiarid climate Palaeoproterozoic Gulcheru Formation Cuddapah Basin India a b s t r a c t An analysis of facies was done to understand the depositional environment and the palaeoclimate of the sedimentary succession from the lower part of the Palaeoproterozoic (∼2.0 Ga) Gulcheru Formation exposed along the southwestern margin of the Cuddapah Basin. Twelve distinct sedimentary facies were identified and grouped into three main facies associations – wadi fan, ephemeral fluvial and aeolian. Identification of the fluvial and the aeolian facies allowed a more elaborate interpretation of the depo- sitional environment and its palaeoclimate. Facies characteristics indicated that the sediments in the beginning were deposited in a dominantly aeolian realm, under warm and semiarid climatic condition. Translatent strata, pin stripe lamination, zibars, high-index granule ripples, sand sheet deposits, grain- flow cross-strata and grainfall laminae, asymptotically down-lapping cross-strata often with erosional lower bounding surface and massive sand-bodies with bimodal fabric, the unambiguous evidences of aeolian depositional regime led to this conclusion. However, the aeolian regime was often punctuated temporarily by fluvial input from ephemeral streams during sudden rainstorm. Depending upon the size, character and availability of sediments, relief difference and the sediment/water ratio cohesionless debris flow, hyperconcentrated flood flow and sheetflood deposits were formed near the basin margin, whereas, coarse-load braided channel deposits were laid further inside the basin. Ephemeral lakes/ponds were formed due to stagnation of floodwater in normally dry interdune lows. Overbank-interdune sed- iments were deposited in those ephemeral lakes/ponds. Amongst the aeolian facies, translatent strata and sand sheet dominate in the west, whereas, massive beds and dunes with well-developed slipfaces dominate in the eastern part. The spatial distribution of the aeolian bedforms suggests development of erg apron to the west and dune field (erg) to the east. The aeolian sediments identified in the Gulcheru Formation may be considered to be amongst the oldest Palaeoproterozoic aeolian sediments of the world. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Development of a number of intracratonic sedimentary basins marked the Proterozoic history of the Peninsular India (Kale, 1991; Chaudhuri et al., 2002). Thick succession of unmetamorphosed ∗ Corresponding author. Tel.: +91 40 27765234; fax: +91 40 27765234. E-mail addresses: himadri.amd@gmail.com, himadribasu.amd@gov.in (H. Basu), rsnsastry@osmania.ac.in (R.S. Sastry), kiranachar1953@gmail.com (K.K. Achar), umamaheswark252@gmail.com (K. Umamaheswar), pariharps1954@gmail.com (P.S. Parihar). 1 Tel.: +91 40 27682257. 2 Tel.: +91 40 27765234; fax: +91 40 27765234. 3 Tel.: +91 40 27767101; fax: +91 40 27762940. 4 Tel.: +91 40 27766791; fax: +91 40 27760254. to weakly metamorphosed sedimentary packages, unconformably resting on the deformed and metamorphosed Archaean to Palaeo- proterozoic basement, are well preserved in these basins. Though majority of the sedimentary packages attest to multiple cycles of fluvio-marine to shelf-slope-basin sedimentation domain (Kale, 1991; Chaudhuri et al., 2002), signature of aeolian (Chakraborty, 1991; Bose et al., 1999; Chakraborty and Sensarma, 2008) and the influence of glacial (Chakrabarti and Shome, 2007) depositional regimes have also been reported from some of them. Of late, aeo- lian deposits have been identified in the Gulcheru (Basu et al., 2007) and Srisailam (Biswas, 2005) formations of the Cuddapah Super- group. Sedimentation in the Cuddapah Basin took place in a series of successively evolved, spatially distributed but interconnected subbasins viz. Papaghni, Nallamalai, Srisailam and Kurnool-Palnad http://dx.doi.org/10.1016/j.precamres.2014.03.011 0301-9268/© 2014 Elsevier B.V. All rights reserved.