Geoinformatika 2019; 4(72) : 82-88
УДК 55.550.4:546.681
ABOUT EFFICIENCY OF EMPLOYING THE MICROSCOPIC METHOD IN STUDYING GEOCHEMICAL PROPERTIES OF BORON IN GEOLOGICAL FORMATIONS OF AZERBAIJAN
N.I. Babayev
zerbaijan State University of Oil and Industry 34, Azadliq avenue, Baku, AZ1010, Azerbaijan, e-mail: nibabayev@yandex.ru
Purpose. In order to meet the ever-growing needs for boron, a significant part belongs to prospection and exploration of new deposits of boric ores. For this purpose, studies to identify geochemical and mineralogical forms of boron formation, migration and concentration in geological formations of Azerbaijan have been conducted.
Design/methodology/approach. Minerals of boron – ulexite and borax were fixed by us in the light fraction of mud volcanoes breccias, in which their number fluctuated from 0,1 to 0,4 %. For a complete and unambiguous diagnosis of these minerals, we selected these minerals from a series of samples under binoculars and then determined the constants in the immersion and in the specially made sections in the transmitted light.
Findings. The brought up issues have been investigated in magmatogene, sedimentary and metamorphic formations of the Republic. As a result, ulexite and borax minerals were first identified and described in mud volcano breccias of the Gobustan, asharite and hydroboracite in the gypsum- and salt-bearing strata of the Lagich trough and Nakhchivan. The mentioned minerals appertain to the hypergene zone of the Earth’s crust, are technologically easily recoverable from rocks and cost-effective in production. In addition, the characteristic geochemical properties of boron in geological complexes of various age and location, common for the territory of Azerbaijan, have been identified.
The practical significance and conclusions. A study of the forms of occurrence of boron in rocks of various genesis showed that boron is present in them in the form of isomorphic impurities in various silicate minerals, in the form of adsorbed boron in clay minerals, in dispersed form in organic matter, and in the form of mechanical impurities in borosilicates. The distribution of boron in various continental and marine sediments revealed a pattern in increasing its content from freshwater sediments, through brackish-water lake sediments to marine humid sediments and further to marine arid sediments. High clark values of boron in clayey rocks are associated not only with the absorption of boron by clay minerals from seawater, but also with its content in the source rocks, that is, clay minerals acquire boron at the place of its formation in the weathering crust, inheriting it from bedrock. The presence of areas of young volcanic activity in an arid climate, the existence of drainage depressions and the overlap of eruption products by continental low-permeable clay sediments created favorable soil for the formation of a volcanic-sedimentary type of boro-occurrence in Azerbaijan. Powerful saline deposits, increased boron content of water and rocks in the area
of development of these deposits created the conditions for the formation of promising halogen-sedimentary ore occurrences in the Nakhchivan, Ismayilli, Shamakhy-Gobustan and Absheron regions. Selectivity in the distribution of boron in bauxites of Nakhchivan was revealed. Bauxites formed from marine clays are enriched with boron more than bauxites associated with continental clay rocks.
Keywords: orthoborates, boric anhydride, hydrogen, crystal, sulfide, structure, metamorphism, magmatism, bitumen, clay, slate.
References
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- Babayev N.I. Boron content of the southeastern end of the Greater Caucasus and the Caspian-Guba region. Baku: Elm, 1998. 114 p.
- Babayev N.I., Martirosyan N.A. Boron and rare alkalis in breccias of mud volcanoes of Azerbaijan. Geochemistry. Academy of Sciences of the USSR. 1973. N 9. P. 1411—1416.
- Gashgai M.A. Petrography and metallogeny of Dashkesan and other iron ore deposits of Azerbaijan. Moscow: Nedra, 1965. 515 p.
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Received 15/11/2019