Ore genetic implications of pyrite and sphalerite compositions fromRajpura‐Daribaand ZawarmalaPb‐Zndeposits, Northwestern India

Abstract

We have studied different generations of pyrite (Py-I, II and III) and sphalerite (Sph-I, II and III), associated with ore mineralization and remobilization stages, from both the deposits. In Rajpura-Dariba, high concentrations of the majority of trace elements in syngenetic Py-I and Sph-I suggest their formation from trace element enriched hydrothermal fluid in SEDEX environment. Enrichment of lattice bound elements in Py-II (As, Co, Ni) and Sph-II (Mn, Hg and Cd) during metamorphic recrystallization of early pyrite and sphalerite indicates their local derivation from host rocks. The Pb, Tl, Ag and Sb rich Py-III and Sph-III in discordant ore indicate their crystallization from low melting-point chalcophile elements enriched sulfide melt. In Zawarmala, the trace element poor natures of diagenetic banded Py-I and Sph-I suggest that the initial ore-forming fluid was depleted in trace elements. Enrichment of trace elements in Py-II (As, Mn, Tl, Cu) and Sph-II (Mn, Hg, As, Ga) in sphalerite-pyrite vein ore signify their derivation from carbonate host rocks. The high abundance of trace elements in Py-III and Sph-III indicates their precipitation at lower temperatures from a trace element enriched hydrothermal fluid during the massive galenasphalerite ore formation. Pyrite and sphalerite from global SEDEX are trace elements enriched as compared to MVT deposits, where their compositions have remarkably correlation with host rocks. Our study highlights the influence of host rock in pyrite and sphalerite compositions and their ore genetic implications.

Dolomite hosted zinc-lead deposits of Zawar, Aravalli Supergroup, Udaipur district, Rajasthan, India

“…11). This variety of ore (sphalerite and pyrite) is poor in trace elements and considered to be diagenetic and suggests that the initial ore-forming fluid was depleted in several trace elements (Bhuyan & Hazarika 2022). In this variety, diagenetic microstructures preserved in low strain zones, are represented by pyrite frambroids (Fig.…”

“…Mukherjee & Sen (1980) indicated low REE in the carbonate assemblages and concluded that the deposit was formed under Bhuyan & Hazarika (2022), temperature data from Tallari et al, (2000). (Chakrabarti, 1966).…”

“…Sphalerite-pyrite in these veins is characterized by enrichment of trace elements in the pyrite (As, Mn, Tl, Cu) as well as in the sphalerite (Mn, Hg, As, Ga). This variety of sphalerite is interpreted to have formed during metamorphism and is characterized by the highest concentration of Mn, Hg, As and Ga (Bhuyan & Hazarika 2022).…”

“…The high abundance of trace elements in pyrite and sphalerite indicates their precipitation at lower temperatures from a trace element enriched hydrothermal fluid during the massive ore formation. Further, high concentration of Co and Ni in PyIII may indicate that deep circulation of hydrothermal fluids through the underlying mafic volcanics of the Delwara Formation of Lower Aravalli Group was responsible for the massive galena-sphalerite ore generation (Bhuyan & Hazarika, 2022). On the basis of width, braided nature and the embayment into the wall rock of ore (after Talluri et al 2000.…”

“…For more than seven decades geological studies were carried out to establish the stratigraphy of the sedimentary succession exposed around ZZB (Heron, 1953;Straczek and Srikantan, 1966;Roy, 2000;Roy & Jakhar, 2002), deformational events of the area (Mookherjee, 1965;Roy, 1995), and to characterize the Pb-Zn sulphide mineralization along with tectono-sedimentary evolution of the host basin (Mookherjee, 1964;Poddar, 1965;Chakraborty, 1967;Sarkar, 2000;Talluri et al, 2000;Bhattacharya, 2004, Sarkar & Banerjee, 2004, Bhattacharya & Bull 2010, Bhuyan & Hazarika 2022.…”