INVESTIGATION OF GEOLOGICAL, GEOCHEMICAL AND GEMOLOGICAL FEATURES OF DIASPOR FORMATIONS IN THE SOUTHWESTERN SIDE OF THE MENDERES MASSIF (AYDIN-MUĞLA)

Abstract

With the increasing interest in gemstones, which have started to offer an important underground wealth for countries. Menderes Massive is one of the most widespread and most important areas of bauxite deposites in the Turkey. Gemstone quality diaspore crystals are formed only within these deposits. In this study, diaspore formations in the southwest wing of the Menderes Massive (Aydın - Muğla) were examined and their geological, geochemical and gemological properties/characteristics were investigated. Bauxite deposits in the study area are observed along the discordance between white crystallized limestone (lower) and gray-dun colored crystallized limestone (upper) contact. The deposits generally extend in NW - SE direction and the samples show massive, pisolotic, oolitic and leopard texture. Diaspore crystals of different lengths and colors are unique to our country, which starting from Bafa Lake and advancing towards Yatağan in the form of dashed arc. It has been extracted as a by-product as a result of diasporitic bauxite production in a single mine for many years and it is not thought to have an economic value. Diaspore formations in the study area are generally observed as lenticular, brecciated, cracked and pockets in crystallized limestones, bauxite and altered zones with calcite, muscovite and chloritoid minerals. Diaspores are generally observed in the form of sheet around Milas. Increased interest in diaspore crystal, especially in the last 30 years and this study will be important in terms of gaining the deserved value of diaspore crystal which is unique to our country. Since it is likely that new diaspore deposits will be found in the region, further studies are planned on this subject. The data to be obtained will be important in the determination of new diaspore deposits.