Modal analysis and geochemistry of two sandstones of the Bhander Group (Late Neoproterozoic) in parts of the Central Indian Vindhyan basin and their bearing on the provenance and tectonics

Abstract

The Neoproterozoic Bhander Group in the Son Valley, central India conformably overlying the Rewa Group, is the uppermost subdivision of the Vindhyan Supergroup dominantly composed of arenites, carbonates and shales. In Maihar-Nagod area, a thick pile of unmetamorphosed clastic sedimentary rocks of Bhander Group is exposed, which provides a unique opportunity to study Neoproterozoic basin development through provenance and tectonic interpretations. The provenance discrimination and tectonic setting interpretations are based on modal analysis and whole rock geochemistry. The average framework composition of the detrital sediments composed of quartz and sedimentary lithic fragments are classified as quartz arenite to sublitharenite. The sandstone geochemically reflects high SiO 2 , moderate Al 2 O 3 and low CaO and Na 2 O type arenite. The high concentration of HFSE such as Zr, Hf, and Th/Sc, Th/U ratios in these sandstones indicate a mixed provenance. The chondrite normalized REE pattern shows moderate to strong negative Eu anomaly which suggests that major part of the sediments were derived from the granitic source area. The sandstone tectonic discrimination diagrams and various geochemical plots suggest that the provenance of the lower and upper Bhander sandstone formations was continental interior to recycled orogen.

Magnetic susceptibility and natural gamma radioactivity as indirect proxies for characterization of sandstones and limestones of the Sabinas basin

“…U / K and Th / U ratios) can reveal different characteristics of sedimentary rocks related to the supply areas (composition and weathering of rocks) and weathering and transportation of sediments (Adams and Weaver, 1958;Banerjee and Banerjee, 2010;Zand-Moghadam et al, 2013). In sandstones outcrops of the Sabinas basin, 99% of the values of U / K ratio are below 2 (Fig.…”

“…Considering research results in other regions (Zand-Moghadam et al, 2013) state that the U / Th ratio also reveals such weathering processes because the majority of its values are greater than 4. This ratio can also indicate the degree of heterogeneity in the provenance of the sediments forming the detrital sedimentary rocks, as well as their depositional conditions (Adams and Weaver, 1958;Banerjee and Banerjee, 2010). Fig.…”

Depositional environment and provenance of Middle Siwalik sediments in Tista valley, Darjiling District, Eastern Himalaya, India

“…According to Reading and Levell (1996), a sedimentary facies is a body of rock whose characters bear the signature of the processes involved in its formation. Mineralogical and textural characters of clastic sedimentary rocks and analysis of modal values of quartz (Q), feldspars (F), lithic fragments (L), monocrystalline quartz (Qm) and total lithic fragments (Lt) including polycrystalline quartz (Q p ) constituting the framework of sandstones help to decipher the sedimentation history and the tectonic setting of the rocks (Pettijohn et al 1972;Basu et al 1975;Suttner et al 1981;Dickinson et al 1983;Dickinson 1985;Arribas and Tortosa 2003;Datta 2005;Kundu and Matin 2007;Banerjee and Banerjee 2010). These established tools have also been successfully and widely applied to understand the palaeoclimate during sedimentation and the provenance of Siwalik (Critelli and Ingersoll 1994;DeCelles et al 1998;Najman and Garzanti 2000;White et al 2002) and other sedimentary rocks (Garzanti et al 1996;Najman 2006;Ullah et al 2006) from different parts of the Himalaya.…”

Provenance study from petrography and geochronology of Middle Jurassic Haifanggou Formation in Xingcheng Basin, western Liaoning Province

“…Sandstone provenance studies have shown that different tectonic settings contain evolutionary trends in their detritus and exhibit specific compositional ranges during redeposition (Dickinson et al, 1983;Dickinson & Suczek, 1979). Clastic detrital components preserve detailed information on the provenance and pattern in which the sediments were transported, especially after modification of the original detritus by the interaction of physical and chemical processes such as weathering, erosion transportation and palaeoclimate (Dickinson et al, 1983;Johnson, 1991), which can be linked to depositional environment (Banerjee & Banerjee, 2010;Johnson, 1991).…”