Mineralogical and geochemical studies of glacial sediments from Schirmacher Oasis, East Antarctica Ashok K. Srivastava a, * , Kirtikumar R. Randive b , Neloy Khare c a P. G. Department of Geology, SGB Amravati University, Mardi Toad, Amravati, Maharashtra 444 602, India b P. G. Department of Geology, RTM Nagpur University, Nagpur 440 001, India c Ministry of Earth Science, Lodhi Road, New Delhi 110003, India article info Article history: Available online xxx abstract Schirmacher Oasis, East Antarctica hosts loose unconsolidated sediments that consist dominantly of sand-silt admixtures with minor clay. These sediments were collected from different glacial environ- ments such as polar ice sheets, inland lakes, exposed bedrock, and coastal shelf areas. Two sediment fractions (coarse 0.25e0.125 mm and fine 0.125e0.063 mm) were separated and chemically analyzed. Mineralogically, the mixture is composed dominantly of quartz and feldspar, and a large variety of heavy minerals: zircon, tourmaline, rutile, garnet, hornblende, hypersthene, enstatite, kyanite, sillimanite, andalusite, zoisite, lawsonite, chlorite, spinel, topaz, and opaques. The clay minerals i.e., chlorite, illite, smectite, kaolinite, and vermiculite constitute a small fraction. There is a mineralogical control over the observed geochemical patterns and anomalies of these sediments. The rare earth element and incom- patible trace element spidergrams show relative enrichment in the coarse fraction as against fine frac- tion, indicating enrichment of the carrier minerals of these elements (mostly heavy minerals) in the coarse fraction. The overall geochemistry of the sediments classifies them as greywacke as per Lindsey, Fe-sand to arenite as per Herron, and sodic sandstones as per Blatt et al. These sediments show quartzose sedimentary provenance, but influence of other unknown sources is also discernible. Transporting agencies for the sediments are commonly meltwater channels and wind. However, transport under influence of gravity, glacier action and sea waves are also envisaged. The sediments have undergone low degrees of chemical weathering ranging between incipient and moderate types. Ó 2012 Elsevier Ltd and INQUA. All rights reserved. 1. Introduction Sedimentary rocks contain wealth of information about the composition, tectonic setting, and evolutionary growth of the early continental crusts (Taylor and McLennan, 1985; McLennan et al., 1993). The original composition of weathered source rocks is a dominant control on the makeup of terrigenous sediments, and therefore geographic and stratigraphic variations in provenance can provide important constraints on the tectonic evolution of the region (e.g. Clift et al., 2000; McLennan et al., 2003; Rahman and Suzuki, 2007; Lamaskin et al., 2008). The geochemistry of sedi- mentary rocks has been used to classify rocks, identify provenance characteristics and investigate palaeoclimatic conditions of depo- sitional basins (e.g. Nesbitt and Young, 1982; Bhatia, 1983; Bhatia and Crook, 1986; Herron, 1988; Armstrong-Altrin and Verma, 2005; Ryan and Williams, 2007). However, little data are avail- able on the geochemistry of the glacial sediments of the study area. This paper characterizes the glacial sediments of the Schirmacher Oasis, East Antarctica on the basis of their mineralogy and geochemistry. The Schirmacher Oasis comprises high-grade metamorphic terrain (Sengupta, 1986; Singh, 1986) forming the basement, which, at places, hosts loose unconsolidated glacial sediments (Lal, 1986; Asthana and Chaturvedi, 1998). These sediments mainly consist of sand-silt-clay, and have not been studied for their geochemistry. The basement rocks, however, show little attention for their basic geochemical aspects i.e., charnokite and granites (Keshava Prasad and Gaur, 2007) and lamprophyres (Hoch and Tobschall, 1998; Hoch, 1999; Hoch et al., 2001). The Oasis, in general, is little explored for its geological aspects because of difficult access and limited time for field work. The recent study of grain-size data by Srivastava and Khare (2009) reveals that the sediments of various glacial and geological units exhibit almost similar textural and statistical characteristics as * Corresponding author. E-mail address: ashokamt2000@hotmail.com (A.K. Srivastava). Contents lists available at SciVerse ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint 1040-6182/$ e see front matter Ó 2012 Elsevier Ltd and INQUA. All rights reserved. http://dx.doi.org/10.1016/j.quaint.2012.07.028 Quaternary International xxx (2012) 1e12 Please cite this article in press as: Srivastava, A.K., et al., Mineralogical and geochemical studies of glacial sediments from Schirmacher Oasis, East Antarctica, Quaternary International (2012), http://dx.doi.org/10.1016/j.quaint.2012.07.028