On the Nature of Ore-Bearing Fluids on the Dal'negorskoe Borosilicate Deposit (Primor'e)

摘要

Study of the oxygen isotopic composition in high-potassic rocks of pre-ore magmatic bodies from the zones of pay datolite mineralization in skarns of the Dal'negorskoe borosilicate deposit allowing us to refine the nature of ore-forming fluids was undertaken for the first time. The concepts on the relationships between datolite mineralization with magmas of alkaline basaltic chambers and parental juvenile fluids prevailed in special publications [ 1 -4]. As this took place, high- and ultrapotassic magmatic bodies usually called trachyte or latite were considered as late ore-bearing phases of the alkaline basaltic chamber. However, mineralogical and geochemical investigations of these rocks [5] demonstrated that these were pre-ore dykes of Paleogene basalt intruded in the zone of a fluid canal, so ore-forming solutions modified basalts to a state of high-potassic rocks. Alteration was carried out by aqueous fluids enriched in Ba, K, B, and Rb and depleted in low-soluble elements, namely Zr, Nb, Ta, La, and Ce. The estimations of oxygen isotope shifts and their correlations in pre- and postore igneous rocks of the deposit obtained in this study confirm these assumptions.