Calcrete profiles in Puthukulam quarry section, Sathankulam region, Southern Tamilnadu, India: implications on palaeoclimate significance

Abstract

Calcrete is an impure limestone which is used as a substitute raw material resources for high-grade primary limestones like shell limestone, meta-sedimentary crystalline limestone in cement industries. They occur as a boundless deposit within the regolith profile sections rest over the basement rocks of granite quarry at Puthukulam Village, near Sathankulam region, Tuticorin District of Tamil Nadu, India. Geology of the area and schematic calcrete profiles stratigraphy are given. Field observation reveals that calcrete occurs as massive, laminated, oolitic, hardpan and lumpy forms in the study area. Micromorphological characters of calcrete of the area are revealing the displacive and replacive texture. And also the micritic and microsparitic calcite deposition is associated with regolith material. X-ray diffraction analysis reveals the general mineralogy and clay mineralogy of the calcrete. The major element geochemistry of calcrete through X-ray fluorescence spectrometry analysis (XRF) indicates that CaO, MgO, SiO 2 , Al 2 O 3 and Fe 2 O 3 are in a higher elevated concentration above 1% than other oxides, such as MnO, MgO, Na 2 O, K 2 O, TiO 2 and P 2 O 5. To evaluate the palaeoclimate significance, results of the proxies of mineralogy, clay mineralogy and major element geochemistry of calcrete are used.

Palaeo-environmental reconstruction of pedogenic calcretes in Sathankulam, Southern India: an integrated approach

“…Geochemical environment of both calcrete pro les of the area were interpreted with advanced statistical methods, such as Pearson multiple correlations, principal component analysis (PCA), and cluster analysis by using the software PAST. Calcrete is formed either by evapotranspiration of alkaline-rich groundwater or by pedogenic leaching of meteoric/surface water (Hill et al, 1999;Queen, 2006;Hema et al, 2010;Udayanapillai et al, 2019;Perumal and Udayanapillai, 2020). Water qualities of the groundwater samples collected from the area were analyzed by APHA (1998) standard procedure.…”

Petrography and geochemistry of the Upper Cretaceous Gryphaea Limestones, Kallankurichi Formation, Ariyalur Group, Trichinopoly, Southern India: Implication for palaeoenvironment

“…Numerous researchers have applied XRD technique for the identification of minerals in sediments and sedimentary rocks (Carrol 1970;Deer et al, 1979;Mitra 1989;Kile and Dennis, 2000;Jimenez-Espinosa and Jimenoz-Millan, 2003;Udayanapillai et al, 2015;Perumal and Udayanapillai, 2020;Ramos-Vázquez et al, 2022;Udayanapillai et al, 2022). Based on high angle XRD mineral analysis (2 theta 0-80 degree), d spacing values and their relative intensities of powdered gryphaea limestone samples reveals the presence of minerals of calcite, siderite, witherite, malachite, smithsonite, azurite and rhodochrosite.…”