Geology and Petrology of Core Samples Taken from The Boyd Mine of The Ducktown Mining District in East Tennessee

Abstract

This project investigates the origin of a copper ore deposit in Ducktown, TN, located in the Tennessee Copper Basin. This deposit was a crucial source of copper from the mid to late 1800s through the 1960s. During the peak of production, the economic importance of the deposit attracted numerous geologists to study the rocks of the ore deposits and their surrounding areas. Despite thorough studies conducted at the time, a consensus on the origin of the deposit remained elusive. Recent advancements in understanding ore mineral formation and analytical methodologies allow a better understanding of the conditions that form copper ores. This project focuses on core samples extracted from the Boyd mine in Ducktown. Utilizing polarized light microscopy, core samples are classified according to their mineralogical relationships. X-ray diffraction (XRD) examines crystal habits and polymorphs, confirming the mineralogical composition. The minerals in the rocks surrounding the ore form during the regional metamorphism of rocks deposited in an ocean-floor environment. The sulfide minerals that make up the ore suggest a volcanic origin. The structure of the ore deposits suggests the ore was introduced before regional metamorphism, meaning they formed when these rocks were still the ocean floor and were likely along the rift where seafloor spreading was occurring.