| Autor: |
Наумко, І. М., Степанюк, Л. М., Занкович, Г. О., Висоцький, О. Б., Котвіцька, І. М. |
| Zdroj: |
Mineralogicheskiya Zhurnal; 2020, Vol. 42 Issue 2, p3-13, 11p |
| Abstrakt: |
Тhe strontium isotope composition was determined for the first time for vein calcite in Oligocene deposits of the flysh formation, north-western part of the Krosno structural-facial unit of the Ukrainian Carpathians. The measured 87Sr/86Sr ratios vary from 0.70 864 to 0.71 030 and do not show any correlation with the location of veins in outcrops, sampling point, composition and age of host rock. They are plotted within the interval characteristic of continental crustal rocks and almost completely coincide with 87Sr/86Sr values (0.708-0.7095) typical of present-day seawater. At the same time they clearly differ from 87Sr/86Sr mantle values as well as values of continental carbonate rocks. It can indicate fundamentally different sources for these fluids and fluids from mantle and continental carbonate rocks. Veinlet-disseminated mineralization is treated to be associated with tectonic activization, influx of deep fluids and formation of mineral paragenesis in veinlets and disseminations by healing of cracks in zones of fracturing and crushing. Therefore fluids are enriched in radiogenic 87Sr up to typically crustal values, what reflects the essential importance of the crustal material in calcite formation. The range of values 87Sr/86Sr ratios obtained is similar to those determined for oil samples of collected from a number of pre-Carpathian fields (0.7084-0.7109). This fact additionaly proves the conjuncting nature of processes of vein filling, dissemination and of hydrocarbon formation within the Carpathian region. It also indicates common crustal source of deep migrating hydrocarbonrich fluids, which inflow into the so-called zones of the development of sealed reservoirs promotes formation of oil and gas fields in favorable geodynamic conditions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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