MINERALOGY AND GEOCHEMISTRY OF THE TIN-TUNGSTEN DEPOSIT IN SINTOK, KEDAH, MALAYSIA

Abstract

The Sintok mine in northern Kedah is known for tin-tungsten mineralization in quartz veins and intrusive rocks as well as in sheeted vein hosted within metasedimentary rock. This study focuses on the mineralogy and geochemistry of ore body within the intrusive that is currently being mined. The ore is dominated by cassiterite and wolframite in a north-south trending ore zone (Zone 1-unoxidized and Zone 2-oxidized). Zone 1 consists of narrow, whitish quartz porphyry with disseminated cassiterite-wolframite. Oxidized Zone 2 consists of a brownish ore zone with intense veining and hosts significant Sn mineralization with up to 1.2% Sn, mainly at the contact with the western wall rock. The samples were analyzed by XRD analysis, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and inductively coupled plasma mass spectrometry (ICP-MS) for the mineral composition of the ore and multi-element analysis. Based on the XRD analysis, the typical metallic minerals that make up the ore mineralization are cassiterite, wolframite with sulphide mineral that oxidized to copper(ii) oxide, arsenic oxide, todorokite (hydrous manganese oxide) and other secondary iron oxyhydroxides. The SEM-EDX study confirms that the ore mineral composition is Sn and W with invariable Fe and minor As and Mn. Multi-element analysis of the bulk samples shows that the Sn-W mineralization is associated with Mn, As, Cu, Zn, Rb and Pb. The Sintok deposit has similar characteristics to other hydrothermal tin-tungsten vein deposits with part of the deposit are hosted in intrusive rocks.