The characteristics, peculiarities, the development of the epikarst, and its role in karstifcation are described here. Epikarst varieties are differentiated, the development of these varieties is interpreted, and the factors infuencing the development of varieties are taken into consideration. <...>

The Neoproterozoic Uinta Mountain Group is undergoing a new phase of stratigraphic and paleontologic research toward understanding the paleoenvironments, paleoecology, correlation across the range and the region, paleogeography, basin type, and tectonic setting. Mapping, measured sections, sedimentology, paleontology, U-Pb geochronology, and C-isotope geochemistry have resulted in the further characterization and genetic understanding of the western and eastern Uinta Mountain Group.

The epithermal Shila-Paula Au–Ag district is characterized by numerous veins hosted in Tertiary volcanic rocks of the Western Cordillera (southern Peru). Field studies of the ore bodies reveal a systematic association of a main E–W vein with secondary N55–60°W veins—two directions that are also reflected by the orientation of fluid-inclusion planes in quartz crystals of the host rock. In areas where this pattern is not recognized, such as the Apacheta sector, vein emplacement seems to have been guided by regional N40°E and N40°W fractures. Two main vein-filling stages are identified. stage 1 is a quartz–adularia– pyrite–galena–sphalerite–chalcopyrite–electrum–Mn silicate–carbonate assemblage that fills the main E–W veins. stage 2, which contains most of the precious-metal mineralization, is divided into pre-bonanza and bonanza substages. The pre-bonanza substage consists of a quartz–adularia–carbonate assemblage that is observed within the secondary N45–60°W veins, in veinlets that cut the stage 1 assemblage, and in final open-space fillings.

Oil and gas-bearing suites are determined in large stratigraphical range of geological structure of the onshore and offshore territory of the Azerbaijan Republic starting from Aalenian subdivision of the Middle Jurassic epoch to the Absheron subdivision of the upper Pliocene. Moreover, middle Pliocene is the basic oil and gas-bearing suite (productive layer) and it prevails according to specific gravity of potential resources and oil and gas-bearing prospectivity.