Depositional and post-depositional setting of Maastrichtian limestone, Ariyalur Group, Cauvery Basin, South India: a geochemical appraisal

Abstract

Major, trace, REE, and stable isotopic composition of Maastrichtian limestones of Cauvery Basin were studied to decipher their depositional and post-depositional environment. The major oxides and trace elements concentration of these limestones were normalized using Post-Archean Australian Shale (PAAS) values. The concentration of CaO is having a significant enrichment, and MgO, K 2 O, Co, Ni, Cu, Zn, Pb, Ba, U, and Th are moderately depleted, whereas Sr and Na 2 O contents are relatively similar to the PAAS values. The PAAS-normalized REE ? Y pattern of Maastrichtian limestones display relatively uniform pattern among the compositionally different limestones: (1) enriched LREE (average Nd SN /Yb SN = 5.03 ± 0.92); (2) positive Ce anomaly (average 1.79 ± 0.16); (3) negative Gd SN /Gd* anomaly (average 0.52 ± 0.02); (4) low Y/Ho ratio (average Y/Ho = 0.14 ± 0.01). The average RREE contents in ferruginous, arenaceous, and biostromal limestones are 65, 64, and 52 ppm, respectively, which indicate that the mineralogical variation plays a major role in incorporation of RREE. The Kallankurichchi limestones have d 13 C values range from -3.2 to -1.1% PDB , and the d 18 O values range between -7.8 and -5.5% PDB . The negative d 13 C and d 18 O values and a moderate co-variation between d 13 C and d 18 O (r 2 = 0.35) indicate that the alteration of original isotopic composition is due to diagenesis. The positive Ce/Ce* confirms the clastic input into the system, and negative Mn* values and Th/U ratios (*0.29-1.4) in these limestones indicate their association with precipitation of carbonates in reducing (anoxic-dysoxic: Th/U B 2) conditions.

Mineralogical and geochemical constraints on the provenance and depositional setting of Sri Lankan marbles

“…Geochemical parameters such as trace elemental composition as well as stable and radiogenic isotope chemistry of sedimentary carbonate rocks are widely being used to interpret their depositional environments and diagenesis processes (Armstrong‐Altrin et al, 2011; Armstrong‐Altrin, Lee, Verma, & Worden, 2009; Bolhar, Hofmann, Siahi, Feng, & Delvigne, 2015; Higgins et al, 2018; Nagarajan, Sial, Armstrong‐Altrin, Madhavaraju, & Nagendra, 2008; Nagendra, Bakkiaraj, & Armstrong‐Altrin, 2011; Siahi, Hofmann, Master, Wilson, & Mayr, 2018). Such geochemical signatures of older carbonate rocks have been used to elucidate palaeo‐oceanic and ‐environmental conditions as well (Chen & Zhou, 2009; Derry, Brasier, Corfield, Rozanov, & Zhuravlev, 1994; Madhavaraju et al, 2004; Tavakoli & Rahimpour‐Bonab, 2012).…”

Rare earth element geochemistry of the Upper Permian limestone: the Kanigorgeh mining district, NW Iran

“…Commonly, REEs with detrital origin have positive correlations with elements such as Si, Ti, Al, K, Sc, Cr, Co, Rb, Y, V, Ni, and Nb, and negative correlation with CaO (Madhavaraju et al, 2010;Nagarajan et al, 2011;Nagendra et al, 2011). Consideration of correlation coefficients between elements Figure 7j).…”

“…Recent investigations showed that distinguishing the terrigenous source for REEs in limestones is possible by considering the correlation coefficients between REEs and certain major and trace elements. Commonly, REEs with detrital origin have positive correlations with elements such as Si, Ti, Al, K, Sc, Cr, Co, Rb, Y, V, Ni, and Nb, and negative correlation with CaO (Madhavaraju et al, 2010;Nagarajan et al, 2011;Nagendra et al, 2011). in the limestone at Kanigorgeh shows that the REEs have a positive correlations with SiO 2 (r = 0.98; Figure 7c), TiO 2 (r = 0.99; Figure 7d), V (r = 0.91; Figure 7e), Co (r = 0.95; Figure 7f), Ni (r = 0.96; Figure 7g), Rb (r = 0.98), Cu (r = 0.99; Figure 7h), and Nb (r = 0.96; Figure 7i), and negative correlation with CaO (r = -0.32; Figure 7j).…”

“…During the past few decades, the behavior and mode of distribution of rare earth elements (REEs) in carbonate rocks were extensively investigated by many researchers Armstrong-Altrin et al, 2003;Nothdurft et al, 2004;Madhavaraju and Lee, 2009;Madhavaraju et al, 2010;Nagarajan et al, 2011;Nagendra et al, 2011;Madhavaraju and González-León, 2012;Song et al, 2014). The studies done showed that the important factors influencing enrichment and depletion of REEs in carbonate rocks are 1) the amounts of detrital materials of terrigenous origin (Piper, 1974;McLennan, 1989;Nagarajan et al, 2011), 2) the variation in oxygen level of seawater (Liu et al, 1988), 3) the proximity to area of origin (Murray et al, 1991b), 4) biogenic deposition from seawater (Murphy and Dymond, 1984), 5) the variation in surface productivity (Toyoda et al, 1990), 6) the lithology and diagenesis (Madhavaraju and Ramasamy, 1999), and 7) scavenging processes related to depth, salinity, and oxygen level of seawater (Greaves et al, 1999).…”

Trace element and REE geochemistry of the Ediacaran Doushantuo Formation from Fanjingshan area, northeast Guizhou province, China

“…Meanwhile, minor and trace elements during the deposition of carbonate rocks could also provide information about the redox conditions of bottom waters (e.g., Azmy et al 2009;Huang et al 2009Huang et al , 2012Madhavaraju and Lee 2009;Ge et al 2010;Nagendra et al 2011;Meyer et al 2012;Palomares et al 2012), volcanic activities (Sial et al 2010), and palaeoproductivity of surface seawater (Font et al 2006;Nédélec et al 2007). The Ediacaran period (635-542 Ma) was a critical time interval for redox condition transition of sedimentary waters from widespread anoxia during the Marinoan glaciation to Phanerozoic oxic deep water environment.…”