The fragment of the skull cap of placoderm Livnolepis heckeri (Luksevics) from the Bilovo Formation (Famennian, Upper Devonian) near the Bilovo Village of Tver Region has been described. The character of the passage of sensory grooves on its external surface is unusual as for this species as for all other bothriolepidids. The oblique cephalic pit-line (or central sensory) groove normally passes from the nuchal on the lateral bones. The left branch of the obhque cephalic pit-line groove on the studied specimen runs from the nuchal onto the paranuchal and only then on the lat­eral. The right branch of this pit-line groove reaches the posterolateral margin of the nuchal, passes along the suture between the nuchal and paranuchal and then transfers into the lateral bone. The branches of the obhque cephalic pit-line groove are subparallel to the posterior margin of the nuchal bone in the Bilovo specimen. The pit-line grooves, which run parallel and subparallel to the posterior margin of the nuchal and anteriorly to the supratemporal (supraoccipital) cross-commissural pit-lines, were earlier determined in some bothriolepidids {Bothriolepis cellulosa (Pander), B. paradoxa (Agassiz) and others) as the middle grooves but not the obhque cephalic. The paranuchalswith the obhque cephalic pit-line grooves were earlier unknown. The unusual character of the passage of the sensory lines is refered to the individual variability in the exoskeleton of L. heckeri. Types of the bothriolepidid exoskeletal variability have been briefly considered. The passage of the pit-line grooves on the external surface of the bothriolepidid and asterolepidid skull roofs has been discussed.

The colloform tin ores from the deposit Verkhnee at the Primorye have been studied with the aid of X- ray spectroscopic microanalysis and the scanning electron microscopy with the energy dispersive analyzer LINK-ISIS that allowed revealing the primary and the secondary zoning of a colloform cassiterite and to determine the phase composition of these formations. The primary zoning of the mineral forms at the early stage of the deposition of stannates from colloidal solutions and is characterized by the alternation of hydrostannates of various composition. The secondary zoning is superimposed zonality, and it forms at the process of the stannate crystallization. The metacolloidal varieties of concentric-zonal aggregates are produced by hydrostannates of Ca, Fe, Cu, In, of variable compositions, soluble in acids, in which the admixtures of As, Al, Si, Cd, Co, Sb, Zn, Ag are marked. Sn content according to the energy dispersive analysis is 42—54%. Infrared adsorption spectroscopy allowed finding out in hydrostannates the presence of the hydroxyl water at the area of the valence vibrations Sn-OH. In the colloform cassiterite a new phase Pb₅ As₂ O₈ with various correlation of Pb and As in size 30—50 mk has been found.

For the first time, the mineral composition and structural features of jewelry ammonite from mine OJSC «Mikhailovcement» in Ryazan Region are studied in detail. Ammonites are associated with sediments of Callovian and Oxfordian stages. Ammonites have a complex zonal structure and mainly up to 96 wt. % pyrite composition. Aragonite, sulphates of calcium and iron, calcite, quartz, apatite, organic matter, graphite, ilmenite, feldspar, mica are established. The walls and partitions of the shells retain the original aragonite composition with lamellar and prismatic layers. Of the impurity elements, heightened contents are fixed (wt.%): As — up to 0,023 and Ni — up to 0,048, and in the range of 0,001—0,01 wt. %: Co, Zn, Mo, Sr, Ba and Pb. The content of radioactive elements U, Th are at the level of background with elevated levels of carcinogenic — As and Pb. The oxidation of pyrite and the formation of a number of micro-inclusions occurred presumably with the participation of bacteria. The main part of the shell is formed by densely fused pyrite crystals of 0,2—0,5 mm in size. There are fine-crystalline and globular pyrite, located on contact with aragonite layers of the walls and partitions of shells. In this zone, most mineral micro inclusions are located. According to their decorative and technological characteristics, ammonites are high-quality jewelry material of the biomineral group. The collection of ammonite shells can be carried out along the way with the development of a mine for the extraction of cement.

There are five great cycles of reef formation in Paleozoic — Early Cambrian, Middle—Late Ordovician, Silu-rian—Devonian, Late Visean—Serpukhovian and Permian. Their upper limits are determined by the corresponding periods of biotic crises and mass extinction events which have been at the borders of the Middle—Late Cambrian, Or-dovician—Silurian, Frasnian—Famenian, Serpukhovian—Baskirian, Permian—Triassic. Cycles differ in the reef prevalence within the planet, in the composition and group diversity of reef-building biota and the duration of reef formation. The longest Silurian—Devonian and Permian cycles are divided with periods of relative decrease in the intensity of reef building into two parts and these periods are clearly observed. These are second order cycles. The bases of this division are global paleogeographic and paleoclimatic causes, and at the beginning of Devon, perhaps, in addition to these reasons, an important role was played by the global biotic event — the appearance of terrestrial biota and, accordingly, a certain redistribution of the flow of nutrients from the ocean to land. In all cases, third-order cycles have been established, the formation of which is determined by purely regional-geological reasons, such as sea level fluctuations, salinity of basins, which are fixed by the overlap of reefs with terrigenous, clay or saline rocks. Similar role is played by the volcanism, as explosive activity stops the growth of reefs.

The Late Devonian kimberlite pipes Arkhangelskaya, Pionerskaya, named after Grib, as well as a number of other pipes, have full sections of crater tufogenic and terrigenous deposits in the Zimneberezhny diamondiferous region, the thickness of which is 120—127 m. The remains of the erosion bell, which was denuded at the stage of regional erosion in the Middle Carboniferous, are characteristic of the Arkhangelskaya pipe. Based on the systematic documentation of the walls of the pilot industrial pit of the Arkhangelskaya pipe, the authors have calculated the initial height of the bell (92 m). The calculation is based on the equality of the volume of host rocks eroded within the annular bell and the volume of terrigenous material contained in the crater deposits. The sequence and kinematics of the formation of crater deposits were reconstructed for the Arkhangelskaya pipe. Four phases of the development of the maar (explosion) crater were identified, which occurred after the injection of kimberlite magma and pyroclastics into the volcano’s vent before reaching the paleosurface: 1 — accumulation of sandstones, 27 m thick, due to erosion of the Vendian socle in a 50-meter-long annular bell with subsidence of the base of the crater with an amplitude of 77 m; 2 — the accumulation of tufogenic and terrigenous deposits with a thickness of 67 m, it was formed under conditions of repeated volcanic activity and a tephra annular shaft with a total subsidence amplitude of 169 m; 3 — terrigenous sedimentation with a total subsidence amplitude of 219 m; 4 — regional erosion in the period from the Late Devonian to the Early Carboniferous and the blocking of the pipe by deposits of Middle Carboniferous and Quaternary system. The depth of regional erosion practically coincides with the estimated height of the eroded bell, equal to 92 m. For the Pionerskaya and Grib pipes, the estimated heights of the erosion bell are 92 and 103 m, respectively. The subsidence of their bases with amplitude of 212—223 m was required to accumulate crater deposits. During the phases of sharp subsidence the collapse of the walls of the crater leads to the formation of coarse deposits and «reefs». After the completion of gravitational erosion, the maar crater switches to the planar erosion mode with the accumulation of fine clastic and chemogenic lake sediments. The causes of subsidence could be the outflow of degassed magma down the crater, ejection of pyroclastic, and compaction of tuff-sedimentary material in the crater.

The oil and gas potential of the south-western part of the Siberian platform is related mainly to the Vendian reservoir rocks. One of the most prospective objects are the deposits of Taseeva series, which include clastic deposits of the Moshakov formation. These deposits are widely developed along the periphery of the Baykit anteclise and adjacent territories. Gas deposits were discovered at the Abakan, Imbinskoe and Ilbokichskoye fields in deposits of Taseeva group. The Vendian terrigenous deposits of the Moshakov formation within the Angara folded zone formed in the environment of different zones of the tidal plain. The deposits have a cyclical structure with a regressive orientation of the sedimentary cyclites in the lower part and a regressive-transgressive one in the upper part. The lower parts of the regressive cyclites are represented by silty clay rocks, which are replaced up in the section by more coarse grained ones. The upper parts of the cyclite are built mostly by the sandy variations. Numerous traces of burrowing organisms have been identified in the rocks, in particular, large forms of Skolithos. Regressive-transgressive cychtes have a slightly different structure. Silty argillites occur in the lower part of the cyclite, which are replaced upwards along the section by mixed sulphate-carbonate-clay rocks. In the middle part of the cychte there are thin sandy interbeds. The reservoir rocks are represented by coarse, medium and differently grained sandstones. The clastic part of sandstones is composed of quartz, feldspars and Augments of volcanic and metamorphic rocks. Void space refers to the intergranular type and is also associated with leaching voids in the zones of dissolution of carbonate cement and feldspars. The reservoir rocks are confined to the upper parts of the regressive and middle parts of the regressive-transgressive cychtes formed in the conditions of the sandy covers of the tidal plain. Reservoir properties of rocks are determined not only by their facies but also to a large extent by the intensity and direction of secondary transformations including fracturing.

A borehole underground leaching enterprise in the Khiagda ore body leads to the uranium mining at a depth of 90 - 300 m below the permafrost distribution zone. At the same time, HDPE (high density polyethylene) pipes have been widely used in borehole underground leaching uranium deposits, which are currently being replaced by pipes from modified UPVC (unplasticized polyvinyl chloride), in order to reduce the accident rate of technological wells in the geocryolgical conditions of their construction and operation. A comparative analysis of the state of the HDPE and UPVC pipes, under these conditions, made it possible to assess the effect on the strength characteristics of wells by temperature and the duration of their use as casing strings of technological wells; and thereby to proves convincingly the need for the transition to the UPVC pipes of a threaded connection with preliminary application of the appropriate sealants on it. The description of these sealants has been given in the paper. And also its comparison allows to indicate the need of using the technical devices proposed by the authors in the form of metal protective couplings for threaded connections , pipe wrenches, special clamps, etc., allowing to reduce generally accidents during the construction and operation of technological wells in the conditions of permafrost zone to 2,5%.

An approximate solution obtained by the author for the problem of the flow of pressure groundwater to a large-diameter water receiving system with a disturbed aquifer with a constant flow rate has been given. The solution has been obtained using the most general method of finding approximate solutions — the method of integral relations of G.I. Barenblatt. Comparison of the computational results based on an approximate solution with computations based on accurate and well-known approximate solution about the inflow of fluids (water, gas, oil) to large-diameter water receiving systems — «big wells» — «enlarged wells». This comparison has shown that an approximate solution provides a calculation of piezometric groundwater level lowering (with a known constant disturbance flow rate) at any point of the aquifer, and also at the wall of the receiving system, with a relative error of less than 5 % for a wide range of times from the beginning of the disturbance. The resulting solution has a disproportionately large area of application in comparison with the «big well» method traditionally used in hydrogeological practice.

The development of Stoylensky iron ore opencast mine during the 50 years is accompanied by the extraction of huge masses of rocks and ores, that radically changes the stress-strain state of the array and the formation of a technogenic aquifer. The long-term quarry exploitation has a result of progressive development of engineering-geological processes: scree, landslides, creeps, suffusion. The development of processes initiated by technological works has a progressive space-time character. The solution of problem of the open pit slope stability which provides accident-free conducting of mining operations at long-term development of the field, is based on modern methodology of calculations. The angles optimization algorithm of slopes staking on Stoylensky iron ore open cast mine and the calculation of the coefficient of stability by different methods with the consideration of the anisotropy of strength properties and fracture density of the solid rock, have been suggested.

Gravimetric and seismic pulsations coincide in time with each other. This synchrony circumstance was previously analyzed for the Eurasian continent, where the data on seismic and gravimetric observations are available. The pulsations of the gravimetric and seismic fields have been appeared to be able to occur not only under the action of meteor showers, but also due to the processes occurring in the atmosphere.Weather-related pulsations are mainly confined to the maritime part of Eurasia and the adjacent coastal part of the continent. Intercontinental pulsations, and their number is much less than in the sea, are observed around the globe and are synchronous with each other. It is likely that the cause of the formation of intercontinental pulsations is the impact of meteor showers on the Earth’s atmosphere, creating as a result of fluctuations in the atmosphere. Ripples in the ocean and coastal zones are created by cyclonic vortices, which are the product of the uneven heating of the Earth’s surface.