Geological Characteristics, Genesis of Iron Ore Bodies and Their Implications for Tungsten Exploration in the Jiuqushan Tungsten Deposit, Western Jiangxi

Tungsten is a traditional advantageous metal mineral resource in China and also one of the indispensable strategic key minerals in the national high-tech sector. The Jiuqushan tungsten deposit is a recently discovered tungsten polymetallic deposit on the Hunan-Jiangxi border. It features iron ore bodies in the upper part and tungsten ore bodies in the lower part, yet the genetic relationship between them remains unclear. This study focuses on the Jiuqushan tungsten-iron polymetallic deposit in Lianhua County, Jiangxi Province. It systematically analyzes the geological characteristics, mineral composition, chemical composition, oxygen isotopes, and genetic mechanisms of the iron ore bodies within the mining area, and discusses the spatial relationship and genetic connection between the iron ore bodies and the tungsten ore bodies. The results indicate an average total iron (TFe) content of 26.32%, an average magnetic iron (MFe) content of 7.43%, and average titanium and vanadium contents of 0.31% and 0.04% respectively, showing a positive correlation with TFe. The average δ¹⁸O_V-SMOW value of magnetite is 4.35‰, suggesting later hydrothermal alteration. The Jiuqushan iron ore bodies belong to the Upper Devonian "Ningxiang-type" sedimentary hematite, which subsequently underwent hydrothermal reduction, partially transforming hematite into magnetite and forming a typical replacement texture of "magnetitization at the margins of oolitic hematite", and show a vertical zoning characteristic of "iron above, tungsten below" with the underlying scheelite ore bodies. Based on comprehensive geological, geophysical, and mineralogical evidence, a metallogenic and exploration model of "exploring for tungsten underneath iron" is proposed, providing an important basis for the exploration of similar deposits along the Hunan-Jiangxi border.