Mineral, chemical and radiological investigation of a black sand at Touzla Cape, near Thessaloniki, Greece |
| |
Authors: | Anestis Filippidis Panagiotis Misaelides Alexander Clouvas Athanasios Godelitsas Nikolaos Barbayiannis Ioannis Anousis |
| |
Institution: | (1) Department of Mineralogy-Petrology-Economic Geology, Aristotle University, 54006 Thessaloniki, Greece;(2) Department of General & Inorganic Chemistry, Aristotle University, 54006 Thessaloniki, Greece;(3) Department of Electrical Engineering, Aristotle University, 54006 Thessaloniki, Greece;(4) Department of Soil Science, Aristotle University, 54006 Thessaloniki, Greece;(5) NRCPS-Demokritos, Institute of Nuclear Technology & Radiation Protection, 15310 Athens, Greece |
| |
Abstract: | A black-sand formation located at Touzla Cape, near Thessaloniki city, Greece, was investigated using optical microscopy, powder-XRD, SEM-EDS, INAA and in-situ -ray spectrometry. This black sand is mainly composed of ilmenite, magnetite, garnet, zircon and rutile. Also present, in minor or trace amounts, are quartz, sphene, pyroxenes, sillimanite, feldspars, biotite, haematite, tourmaline, chromite, niobian-rutile and pyrrhotite. Niobian-rutile and pyrrhotite were found as inclusions in ilmenite and magnetite respectively. The radioactivity measurements indicated contributions of the uranium and thorium radioactive series and of 40K and 137Cs, and the maximum value of the total absorbed dose rate in air was found to be 62, 172, 8 and 2 nGy h-1 respectively. The main radioactivity of the uranium and thorium series is attributed to the fractions of zircon (304 µg Th g-1 and 157 µg U g-1), of ilmenite (89 µg Th g-1) and to a lesser extent to the fraction of garnet (5 µg Th g-1). The zircon fraction also contained 5076 µg Hf g-1. Some minerals and elements (Ti, Zr, Hf, Th, U) contained in the black sand could be of potential economic value. The high proportions of monomineralic grains along with the variations observed in mineral phases, in colour, in sphericity, in roundness, in grain size, in composition and in mineral inclusions, imply that the minerals and grains were subjected to several cycles of weathering and sedimentation, as well as being derived from multiple source rocks and areas. |
| |
Keywords: | Black sand radioactivity zircon ilmenite rutile |
本文献已被 SpringerLink 等数据库收录! |
|