Morphological, microstructural and mineralogical dataset of bauxite over Mainpat plateau from a part of Deccan traps, Surguja district, Chhattisgarh

Abstract

In this study, we present the main findings from microstructural and mineralogical studies and their implications for the genesis of bauxite/laterite in Mainpat plateau. Megascopic studies showed reddish laterite to off-white bauxite. Strong hydrolytic action formed small oolites and large pisolites with sizes of 1–2 cm in diameter. Pisolites and oolites were elliptical, circular, and as broken pieces. Matrix of gibbsite and hematite was found in petrographic observations. Morphological characteristics include pisolitic, oolitic, lamellar, and euhedral gibbsite. Microstructures discovered were spongy gibbsite, flower-like crystals, elongated gibbsite, and framework type. Crystals of gibbsite were found to be predominant with partially crystallized ilmenite and hematite as subordinate phases. Scattered bauxite crystals made free pores for passage of solutions enhancing leaching conditions. Al, Ti, Fe, Si, Cu and Zn were identified as significant components; out of which, Al and Ti have the highest concentration. The samples have high alumina constitutes of 61.45% and 65.40% with a low iron content of 6.66% and 5.61%. High Ti content of 19.38% and 17.55% might be due to strong hydrolytic action during the alteration of basalt to bauxite. Low Si content of 2.68% indicates strong leaching activity. XRF analysis showed that the samples have undergone strong lateritization. XRD examination of bauxite/laterite revealed a mixture of minerals like gibbsite, boehmite, goethite, hematite, and anatase. Enrichment in boehmite shows in situ weathering. The study aims to extract the genesis and depositional characterization of bauxite through its morphological, microstructural, and mineralogical properties.