Prospects for the Discovery of Natural Hydrogen in the Voronezh Anteclise.

Topical issues on the prospects of the Voronezh Anteclise for detection of natural hydrogen occurrences are considered. The most important factor of natural hydrogen localization is the surface of the Precambrian basement. The vault itself is surrounded by a system of depressions and aulacogens, which is generally favorable for the formation of gas emanations. The presence of ultramafic and mafic rocks, distributed at different structural and age levels, is an additional material factor of the localization of natural hydrogen. The trappean formations of the Novogol Complex and the Upper Devonian basalt covers are most promising. Four gas transportation systems of different ages can be distinguished within the Voronezh Anteclise (Losevka Suture Zone; Tim- Yastrebovka and Belgorod-Mikhailovka Paleoproterozoic rift structures; depressions and aulacogens formed in the Upper Proterozoic; and structures formed in the Upper Devonian). The Precambrian–Phanerozoic unconformity surface is a transportation system and a major mega-trap, but it is "perforated" because of many circumments, through which a significant part of hydrogen is lost. This paper characterizes the surface circular and oval subsidence structures, their possible origin, and their role in hydrogen degassing. Phenomena accompanying circumments include "bleaching" of chernozems, desertification, and increased concentrations of noble metals, primarily platinum group elements (PGEs). The analysis of the mineragenic factors controlling the transportation and accumulation of natural hydrogen within the anteclise, in general, shows very high prospects for the structure considered. [ABSTRACT FROM AUTHOR]