Microthermometric characteristics of vein type U-Th enrichment observed in the Fault Zones in Northwest of Arıklı (Çanakkale-Turkey)

Abstract

U-Th enrichments are observed in many regions in Western Anatolia. There are also U and Th enrichments in the fault zones developed in the tuffs in Arıklı in Biga Peninsula. The characterization of the mineralization is vein type and epigenetic formation. Çetmi Ophiolitic Melange forms the basis of the region. Küçükkuyu formation, which consists of Arıklı tuff member and shale-sandstone member, is located on this unit. The youngest unit in the region is diabase dykes. The study area was affected by deformations during the Paleogene period and E-W and NE-SW extended dip slip fault systems were developed. In the fault zone around Örencik Tepe, 64-1640 ppm values for U and 302-11813 ppm values for Th were obtained respectively. At the same time, hydrothermal magnesite breccias developed in this fault zone. Because of microthermometric assessments in these breccias associated with mineralization, it was determined that the homogenization temperatures (Th, o C) were between 282-348 o C and the % NaCl salinity equivalents were between 4.2-8.0 respectively. It was identified that the solution system of the liquid inclusions is as H2O-MgCl2-CaCl2 and the density of the liquids is between 0.58-0.74 g/cm 3 .