Geochemistry and petrogenesis of intrusive rocks of Chadormalu deposit; an implication on whole rock geochemistry and Sr-Nd-Pb isotopes

Sr-Nd-Pb isotopes and whole-rock geochemical analyses were carried out on plutonic rocks of the Chadormalu district to constrain the magmatic history of the Cadomian orogeny of the northern Gondwana margin during Late Precambrian–Early Paleozoic times. Despite the similarities in the geochemical data, i.e., calc-alkaline affinity, enrichment in large ion lithophile elements (e.g., Rb, Ba, K, and Cs), and depletion in high field strength elements, e.g., Nb, Ta, P, Ti, and rare earth element patterns, bulk rock Sr-Nd isotope data rull out the co-magmatic nature of investigated basic (gabbro) and felsic (granite) magmas. Sr-Nd isotopic data (e.g., ɛNd(t)= -3.6 to +1.8) along with rather high (207Pb/206Pb)t attest to the crust-dominant, and mantle-derived melts for the granitoids and gabbros, respectively. The investigated zircons yielded the older ages for the gabbroic samples. The extensional tectonic regime is followed by slab retreat or delamination brought flare-up of the oldest arc-related igneous rocks and interacted with Cadomian basement to form the investigated granitoid melts. The gabbroic rocks show geochemical and isotopic disruption and elevation of L-MREE/HREE ratios on the chondrite-normalized rare earth element (REE) patterns; interpreting the evidences of mantle heterogeneity and interaction with Paleoproterozoic basement.