Lower Horizons Research Articles

LANDUSE FEATURES IN A MOUNTAIN AREA AND THEIR EFFECTS ON THE PROCESS OF SYLVATISATION (STRYY DISTRICT LVIV REGION)

The Skole District that is nowadays a part of newly established Stryy District (Lviv Region) is entirely situated within the range of the Ukrainian Carpathians. Its area encompasses the Skolivsli Beskydy and the Stryy-San Highland physiographic regions featuring a dominance of considerably high altitudes above sea level, terrain disarticulation, and afforestation. Establishing new villages alongside rural population’s natural increase and land reforms (the capitalist stage of land use (after the abolition of serfdom in 1848) and Soviet stage of land use) called for respective increase in agricultural lands. Forested lands in the Ukrainian Carpathians were the source for such an increase therefore cropland and pasture lands were emerging from deforestation. Harsh weather conditions and low soil fertility significantly impacted the further agricultural land uses in the mountainous region. However, wide-scale decline of agricultural lands occurred in the period of the collapse of the former USSR due to decline of collective and state farms. As a result of denationalization with subsequent privatization of agricultural lands there are nowadays 31 303 land owners and land users in the study area, 97,54 % of which are physical persons. At the same time, despite such remarkable figures citizens share less than a half of total lands for agriculture, residential and construction purposes, whilst the state forestry enterprises are using 51,11 % (75 173,50 ha) in total. In contrast to lowlands, animal farming and husbandry in the Skole District is held exclusively by households. In recent years local animal husbandry is experiencing the livestock decline that leads to certain reduction in the share of both hay meadows and pasturelands. Thus, from 2009 to 2016 the total area of fodder lands in the district decreased by 65 ha (ca. 0,2 % of total privately owned agricultural lands). I assume that ongoing land reform will cause further increase in fallows in the Skole District. In order to better comprehend the processes of spontaneous reforestation (sylvatisation) in a mountain region (the Pohartsi boundary, Koziova village, Stryi district, Lviv regionthe ) four study plots were selected representing the successional sequence: forest → pasture → hay meadow → arable lands. The study showed that areas that were previously used for pasture and were not plowed, are restored to their natural state much faster. These areas are characterized by satisfactory physical, physico-chemical and biotic properties. The decrease in acidity towards the neutral side is explained by an increase in the activity of catalase and urease by approximately 1.5 times. In connection with the developed grass cover, slightly higher nitrogen values were recorded in the upper soil horizon. Due to the absence of a regular annual supply to the base and replenishment of its nutrient reserves due to precipitation and waste of dead phytomass, the content of humus in the upper horizon of the base is half as much as under forest biogeocenoses. Plowing (overturning the lower horizons to the mountain, and vice versa) is a very strong anthropogenic factor, which leads to the almost complete destruction of natural vegetation on the cultivated area and a radical change in the main properties of the soil cover. According to some indicators: physical (total sparability), physico-chemical (nitrogen nitrate and ammonia), biotic (urease, catalase, biomass of microorganisms) in the upper humus horizons were even somewhat close to anthropogenically unaltered ecosystems. However, the changes in the indicators of the density of the soil structure and its solid phase corresponded to the depth of plowing. And the humus content was several times lower than under forest biogeocenoses. Areas that were not plowed in the past are restored due to the main rock of the region Picea abies (L.) Karst.. Areas that were devastated in the past are recovering much more slowly. Such areas begin to overgrow with Alnus incana (L.) Moench., Rosa canina L., Bеtula and others Key words: land use; land owners and land users; fallows; agricultural lands; mountainous region; Skolivski Beskydy.

Features of the spatial structure of the macro- and meiobenthos community of the lagoon ecosystem of Kislaya Bay head (Gulf of Kandalaksha, White sea)

The spatial and species structure of meio- and macrobenthos communities of the Kislaya Bay (Gulf of Kandalaksha, White Sea) lagoon ecosystem was analysed. A total of 32 species of benthic organisms (including 11 species of invertebrate larvae) and 9 species of seagrasses and algae were found. Eumeiobenthos groups were identified to the level of large taxa (nematodes, harpacticoids, ostracods, turbellaria). The highest total biomass of macrobenthos organisms was mainly observed in the lower horizon of the littoral zone and at the exit from the lagoon (high biomass of Mytilus edulis populations). For meiobenthos biomass was the highest in the middle and upper littoral horizons and in the bayhead. This may indicate a complementary distribution of meio- and macrobenthos: the role of meiofauna grew where macrobenthos development was somewhat inhibited. An analysis of the similarity of meio- and macrobenthos of different habitats revealed differences in the species structure of communities between the three littoral horizons – upper, middle, and lower. Communities of the lower and middle horizons of the littoral zone exhibited a greater similarity of the species structure than communities of the upper horizon. The differences in the structural characteristics of the community lengthwise – with increasing water salinity, are less pronounced (especially when compared with the corresponding structural changes in meio- and macrobenthos in the Chyornaya River estuary). This is probably due to the milder salinity conditions in the lagoon versus the Chyornaya River estuary, lower impact of this factor on the distribution of aquatic organisms and, accordingly, smaller change in the species structure of the community lengthwise – from the bayhead towards the sea.

Influence of Robinia pseudoacacia L. and Quercus robur L. artificial forest plantations on the particle-size distribution of calcic chernozem

The particle-size distribution is one of the most important characteristics of soils, which determines most of their properties and features of the main regimes. Artificial forest plantations in the steppe act as a powerful environment-transforming factor, which over time is capable of changing even quite conservative properties of soils, including their particle-size distribution. The study of the influence of forest plantations on the particle-size distribution was carried out using soil samples taken from calcic chernozem, chernozem under the plantation of R. pseudoacacia L. and under the plantation of Q. robur L. The determination of the particle-size distribution was carried out by the pipette method, with the preparation of the sample by trituration with a solution of sodium pyrophosphate. The classification of granulometric fractions is given according to N. A. Kaczynskii. The analysis of the characteristics of the ratio of particle-size distribution of the studied chernozems revealed that the zonal chernozem is characterized by an increased content of the sand fraction and a reduced content of the silt fraction in the H1 and H2 horizons compared to the lower horizons. The calcic chernozem under the plantation of R. pseudoacacia L. is characterized by a relatively uniform distribution of the content of sand, dust and silt fractions along the soil profile. In calcic chernozem under the plantation of Q. robur L., the maximum content of the sand fraction was found in the surface horizon, with a gradual decrease in the content of this fraction with depth, while the content of dust and silt fractions increased with depth. The growth of R. pseudoacacia L. and Q. robur L. plantations on calcic chernozems leads to an increase in the content of sand fractions and a decrease in dust and physical clay fractions. There is also a certain change in the profile distribution of fractions, especially sand, under the influence of the growth of forest plantations. Each of the investigated calcic chernozems is characterized by a specific ratio of «sand : dust : silt» fractions, which indicates a different genesis of granulometric fractions.

Methods of creating a conveyor lift route in a deep pit

Purpose. Improving the technology of stripping and schemes for creating a steep trench in a deep pit makes it possible to create new cargo flows and develop mining operations. The purpose of the research work is to determine a more attractive scheme for the formation of the conveyor route. The paper compares two technological schemes: the creation of a steep half-trench to the lower horizons with the hilling of rocks and the formation of a working in the rocks in the form of a trench. The above purpose of the work is to substantiate an effective scheme for creating a steep trench for the subsequent placement of a conveyor stack on its base. This will allow moving the rock mass from the lower horizons to the upper ones at a lower cost. The considered schemes for creating the steep trench allowed it possible to determine the volume of preparatory work, the most attractive scheme for creating an inclined working during opening lower horizons in the conditions of the operating open pit of Poltava GOK, which makes it possible to reduce the use of dump trucks inside the open pit. The methods. The method of vertical sections was used for the calculation of the volumes of run-off-mine during the formation of the trench. A geographic information system (GIS), and a software package K-MINE was used for research. The method of comparing the scope of work and creating a conveyor route by options allowed to determine the most appropriate way of doing work. Findings. The parameters of a steep trench and half-trench were studied, including the established scope of work within the steep layers of the western side of the PGOK open pit. Opening with steep trenches allows for the placement of an existing elevator with the placement of a crushing and transfer station containing a mobile crusher from KRUPP. Implementing the scheme with a steep trench in the rocks, the scope of work is 79.555 thousand m3. For the construction of a half-trench, the amount of work is 733,887 thousand m3. Building capital trenches and semi-tranches in the conditions of the open pit of the Poltava Mining and Processing Plant, preference is given to semi-trenches, which are created from rocks (without drilling and blasting). The originality. The options and parameters for creating steep trenches for further placement of a conveyor stack on its base are considered. The scheme for moving the rock mass from the lower horizons to the upper ones has been improved, graphical dependencies of the scope of work have been established, and a comparison of technical indicators has been made for creating a steep trench and a half-trench. Practical implimintation. The considered schemes for creating a steep trench allowed to determine the volume of preparatory work, to establish the most attractive scheme for the creation of an inclined work in opening the lower horizons in the conditions of the active open pit of the Poltava GOK, what makes it possible to reduce the use of dump trucks inside the open pit and improve the schemes for moving rock mass.

Coupled and uncoupled to δ34S behavior of gold and silver in pyrite and marcasite from the low-sulfidation Sarnak gold deposit, SE Bulgaria

In this study, the contents of Au and Ag in five pyrite±marcasite samples from the Sarnak gold deposit, the respective δ34S, and the sample distances to the contact between metamorphic basement and overlying sedimentary cover were considered. We found that two samples from lower horizons (levels of 69 and 30 m below the contact) display relatively low Au and Ag contents, negative values of δ34SV-CDT (–3.14 and –6.42‰) and pronounced oscillatory zoning, resulting from oscillating contents of As. Three samples from higher horizons (levels of 8, 7 and 0 m below the contact) have higher Au and Ag contents, positive or slightly negative values of δ34SV-CDT (+0.5, +1.73 and –1.85‰) and poorly expressed or absent arsenian zoning. Two of them contain microscopic electrum and adularia. Based on these contrasting features we assume different mechanisms of precipitation: intense fluid-rock interaction for samples from lower horizons under steady conditions and boiling of fluid for samples from higher horizons under fluctuating conditions.

Hydrologic regulation of clay-mineral transformations in a redoximorphic soil of subtropical monsoonal China

Abstract Clay-mineral evolution in supergene environments is commonly a complex process subject to hydrologic influences on clay-mineral transformations, yet these influences remain insufficiently investigated to date. A quaternary red soil profile with evident redoximorphic features in subtropical monsoonal China was investigated with a focus on processes of secondary clay-mineral transformation. Evidence provided by soil physical and chemical descriptions, clay-mineral analysis, spectroscopic characterization, extractions of pedogenic Al and Fe species, and geochemical compositions reveals a complex relationship of clay minerals and iron phases to pedogenic weathering conditions as a function of depth in the studied soil profile. The soil profile can be divided into a homogenous horizon (HH; 0–2.0 m), a redoximorphic horizon (RH; 2.0–6.0 m), and a basal layer (BL; 6.0–7.2 m), and these three horizons are dominated by various intermediate clay phases. The HH is characterized by moderately acidic conditions (mean pH = 5.2) and low total organic content (TOC; TOC ≤2.1 g kg–1). More importantly, compared with the lower horizons, the HH contains significantly more active acid-forming cations, as reflected by a greater abundance of Al phases and higher aluminum saturation levels. We infer that the occurrence of hydroxy-interlayered vermiculite (HIV) in the HH is tightly coupled with the nature of the soil acidic pools, which include both H+ ions (i.e., pH) and active acid-forming cations (e.g., Al3+ and Fe3+). The reaction pathway from primary minerals to final weathering products appears to be highly sensitive to dynamic hydrological processes. HIV is favored in generally oxic, well-drained soil systems with adequate acidic cations to maintain acidic weathering. When soils are more waterlogged and the aqueous solution is dominated by base cations, primary minerals tend to transform to smectite group minerals. Therefore, discrete smectite, interstratified illite-smectite (I-S), and interstratified kaolinite-smectite (K-S) were observed only in the RH and BL. We present a novel framework that links clay-mineral transformation pathways to soil hydrological disturbances, providing new insights into understanding the kinetics of water-mineral interactions in natural soil systems.

Analysis of the Influence of the Vertical Coaxiality of the Pillars on the Stability of the Resistance Structures, from the Ocnele Mari Saline

Abstract The Ocnele Mari rock salt deposit is exploited with small rooms and square pillars, on the horizons +226 m and 210 m. Following the exploitation of the lower horizon +210 m, the floor between the two horizons suffered instability phenomena, marked by fractures and cracks and local degradation of the pillars.Since the pillars at the two horizons have certain deviations from the coaxiality, the question was raised whether the instability phenomena were generated by the deviations from the coaxiality.This article presents the stability analysis of bearing structures, taking into account the actual geometry of pillars, 3D finite element analysis and analysis of safety factors at the ceiling level, calculated from 2D finite element models. The final conclusion is that the instability phenomena that occurred at the Ocnele Mari Saline were generated by the state of stresses and strains, produced by the spatial distribution of the underground voids and the geomechanical characteristics of the rock salt and insignificantly, by the deviation from the coaxiality of the pillars.

Determination of Horizon, Its Boundary and Depth in the Soil Profiles of North Western Himalayas

The scientific study of the soil started almost 70-80 years ago with two school of thoughts, one worked in the lab and others in field. The main aim of the researchers studying in the field was to determine the profiles of soil along with its horizons so as to extent the knowledge on physical, chemical and biological properties. The distinctness of soil with depth means that soil has unique profile. All the soils in the world has some specific depth functions. The change of soil color or soil texture in a soil profile can be considered a good indicator of the soil formation and process and has been used as a proxy for degree of development or soil age. Uniform, gradational and rapidly changing soil textures are examples of soil profile forms used for soil classification. In the current study we studied twelve profiles having four different land uses and observed several horizons having various boundaries. The upper horizons were having diffused and wavy boundaries than the lower horizons. There was seen a clear relationship between the horizons and the various land uses. The study is very important as the soils in Himalayas are not very well developed and are prone to erosion. The study will help researchers and policy makers.

Characterizing Groundwater Chemistry and Recharge in the Critical Zone of an Agricultural Claypan Watershed

AbstractSoils with low permeability horizons (e.g., claypans) are vulnerable to loss of nutrients through surface runoff along with preferential flow paths through the restrictive horizon to deeper aquifers. Partitioning between these hydrologic pathways is important to determine transport processes and develop strategies that mitigate stream contamination. Our objective was to investigate controls on groundwater chemistry and recharge pathways using natural geochemical tracers in the Goodwater Creek Experimental Watershed in Missouri, U.S. Groundwater samples were collected during 2011–2017 from 32 piezometers ranging from 0.13 to 16 m deep along with stream water and precipitation. Diagnostic tools of mixing models indicated that chemistry of perched water directly above the claypan and shallow groundwater immediately below was controlled primarily by chemical equilibrium. Five solutes behaved conservatively in most deep piezometers (>5 m), reflecting mixing of two end members and the lack of significant denitrification processes. End member mixing analysis showed that the deeper groundwater originated primarily from groundwater at similar depths, often upslope or from strata directly above, with small contributions from perched water, highlighting the importance of both horizontal and vertical preferential recharge pathways. Vertical pathways are likely dictated by soil heterogeneity throughout the critical zone and do not occur synchronously with precipitation events or simultaneously over all piezometer locations. The complex recharge pathways provide stochastic conduits for nitrate transport to deeper aquifers where legacy stores accumulate, presenting a significant challenge for water quality management in watersheds with restrictive soil horizons and spatially and temporally heterogeneous preferential flow pathways, including the Mississippi River Basin.

Characterization of nano-minerals and nanoparticles in supergene rare earth element mineralization related to chemical weathering of granites

AbstractIon adsorption-type rare earth element (REE) ore deposits in South China are a major source of heavy rare earth elements (HREE) around the world, which are of considerable economic and strategic significance. In these ores, REE is enriched in the clay minerals, specifically kaolinite and halloysite, which are derived from their parent granitoid by the weathering process. However, the mechanisms of supergene REE mineralization remain unclear. We investigated the nature and origin of supergene REE mineralization, based on a nanoscale study of a typical REE-mineralized granite regolith profile (ΣREEmax = 1201 ppm) in the Dazhou super-large, ion adsorption-type REE deposit, Guangxi Province, South China. Bulk mineralogical and geochemical analyses, coupled with novel nano-characterization techniques [i.e., hollow fiber flow field-flow fractionation inductively coupled plasma-mass spectrometry (HF5-ICP-MS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM)], were used to determine the nature of the nano-minerals and nanoparticles in the regolith samples. X-ray diffraction and SEM-EDS analyses revealed that ion-adsorption clay minerals are dominated by platy-shaped kaolinite and rod-like halloysite (10 and 7 Å) within the regolith. The average clay mineral contents decreased from 38 to 15% from the fully weathered horizon to the semi-weathered horizon, whereas the proportion of halloysite increased in the clay mineral fraction in the deep horizons. The REE-bearing nanoparticles consist predominantly of macromolecules of organic matter (2–5 nm) and clay minerals (5–40 and 40–80 nm) according to the HF5-ICP-MS analysis. There is a close association between REE and Al contents in particles with sizes of 5–40 nm in the semi-weathered horizons and 40–80 nm in the highly weathered horizons, which indicates that nanoscale clay minerals (halloysite and kaolinite, respectively) are important REE carriers. In addition, nanoscale secondary REE mineral phases, including oxide, silicate, and phosphate, were identified by the SEM and TEM observations. These phases are typically adsorbed onto the surfaces of clay minerals, specifically rod-like halloysite, but have different occurrences in the regolith profile. Cesium-oxide (cerianite) and Ce-silicate (cerite) occur mainly in the upper horizon of the regolith profile, whereas low-crystallinity REE phosphates [rhabdophane-(La)] occur mainly in the lower horizon of the profile. Our results indicate that nano-minerals and nanoparticles affect REE enrichment and fractionation during granite weathering. Migration and accumulation of REE-bearing nano-minerals were caused by leaching and neoformation of REE-bearing nano-minerals during secondary precipitation. These processes contribute to the formation of supergene REE mineralization in granite regolith.

Mineralogical and Petrographic Features of the Lower Horizon of Ferruginous Laterites and Ferriplantites of the Fouta Djallon–Mandingo Province (Guinea, West Africa)

Mineralogical and Petrographic Features of the Lower Horizon of Ferruginous Laterites and Ferriplantites of the Fouta Djallon–Mandingo Province (Guinea, West Africa)

Changes in Chernozem Erosion Resistance Due to the Evolution of Clay Plasma in Western Ukrainian Region

The major problem of efficient agriculture in Ukraine is increasing rates of the water erosion in Chernozems. The aim of this research study is to describe the negative trends in the clay profile for evolution of various Chernozem sub-types, which lead to the reduction of erosion resistance. Cohesion strength between soil aggregates is determined dominating smectite minerals in clay plasma. Disturbing the stable balance between the organic and mineral matter are the main causes of soil disaggregation. Evolutionary changes of Chernozems clay plasma are studied using the methods of chemical and x-ray diffractometry analysis. The processes of de-humification have been destabilized the mineral colloidal complex and smectite-illit dynamic equilibrium in soils. From Haplic Chernozems to Greyzemic Chernozems, the substantial loss of highly dispersive smectite material is observed. The dominance of inactive illite clay in the arable layer of all Chernozems reduce the role of clay plasma in formatting of water-stable micro- and macrostructure. According to the anti-erosion properties of clay plasma, the Chernozems under study is found in the following order: Haplic Chernozem > Greyzemic Chernozem. These properties reduce themselves following the increase in soil hydromorphism stimulating argillification in the middle and lower horizons due to the processes of lessivage and inter-soil weathering. Anthropogenic evolution of Chernozems, when caused by the changes in the silicate fraction of soils, is basically of irreversible degrading nature.

Deep aquifers as strategic groundwater reservoir in Spain

The objective of this paper is to establish a definition of deep aquifers, develop a methodological proposal to help select them as strategic groundwater reserves and develop a first inventory of deep aquifers in peninsular Spain, organized by hydrographic districts. The basic premises followed to consider a permeable formation as a deep aquifer are: water table depth greater than 300 m in free aquifers or the top of the permeable formation in the case of confined aquifers. A deep aquifer is also considered to be the lower horizon of very thick aquifers (from 300 m), from which the most superficial horizon is used. The definition of the potentially favorable areas and the initial characterization is based on a compilation and synthesis of geological and hydrogeological information, structured in 5 large blocks: location and identification, geology, hydrogeology, current status and bibliography. For its evaluation, a flowchart has been proposed with the basic lines of the evaluation process. The relevant aspects for suitability would be: stratigraphy and structural geology, prior knowledge of the conceptual model and water renewal, quality, viability of exploitation, effects, final knowledge, and management and governance. The final result allows the aquifer to be classified into three categories: strategic groundwater reserve, punctual reserve or non-viable reserve. The inventory carried out encompasses a total of 64 deep aquifers located in 13 basin districts. Finally, as example, three deep aquifers are presented: Amblés Valley, Madrid detritic aquifer and El Maestrazgo.

The procedure of planning the face shovels layout using the technologies of the Mining and Geological Information Systems

Introduction. The article considers options for face shovels layout in an open pit based on the developed procedure of mining operations scheduling, which uses block modeling and considers the throughput of rock mass at the horizons, the length of the active extraction front, the quality of the mineral, the specified intensity of excavation, the accepted models of shovels and other attribute electronic data. The approach proposed in this procedure allows to consider many options for face shovels layout in an open pit and choose the best option in a short time in a semi-automatic mode. Research objective is to develop a method for automated layout of shovels along the working horizons of an open pit, based on the results of block modeling. Methods of research. Face shovels layout on the working horizons of an open pit is based on the calculations, computer modeling and technical and operating parameters of shovels, as well as the active extraction front assessment. The main step in solving the problem is to build ore body block models, simulate mining operations, and built an open pit model based on the periods of field development. Based on the results of block modeling, the optimal length of the excavating block on the working horizon for the selected face shovel model is determined. Research results. Based on the block model, shovels layout along the working horizons of the open pit is designed. Conclusions. The proposed procedure, in a short time in a semi-automatic mode, allows to solve the problem of lower horizons opening in deep pits, consider numerous options for face shovels layout in an open pit and choose the best option, minimizes production risks when developing complex deposits and carrying out comprehensive extraction of raw materials.

Peculiarities of formation of the forest litter of the water protection pine plantations in the Ukrainian interflue of the Dnipro and Desna rivers

The effective performance of ameliorative functions by water protection plantations is largely determined by the development of the forest litter, its structure, capacity, quality composition, and degree of mineralization. Therefore, the aim of the study was to identify the features of the formation of the forest litter of pine plantations of the Ukrainian interfluves of the Dnipro and Desna. The study of forest litter was carried out on the accounting sites in all age groups of plantations, in which 22 test plots were laid. Litter samples were taken in between rows and directly in rows of forest plantations. During the analysis of the qualitative composition of the forest litter of young plantations, the dominance of the upper horizon of the inactive fraction, which consisted mainly of needles and branches, was revealed. Here, the share of inactive litter in the conditions of moist poor pine site and moist relatively poor pine site was 8.13 t/ha or 85.1% and 12.54 t/ha or 92.1%, respectively. A large amount of dust, which forms the active fraction, was recorded in the lower horizon. Its stocks were 5.3-5.6 times higher than the reserves of inactive litter. In general, in young pine forests in the conditions of moist poor pine site, the stock of inactive litter is 15.10 t/ha (28.1%), while its presence in of moist poor pine site is 17.91 t/ha, 36.5%. In middle-aged pine forests, the share of the active litter fraction increases, which is a consequence of the active action of its decomposition processes. The share of active litter is 79.3% or 155.29 t/ha in mature stands of the conditions of moist poor pine site. This is evidence of the intensification of the processes of mineralization and activation of the circulation of substances. Three horizons are clearly distinguished in the litter of plantations of older age groups, with a strong connection between them. The lower layer of the forest litter of water conservation plantations is permeated with physiologically active roots, which forms its dense type of structure. Under such conditions, during the separation of the lower layer of litter from the upper one, it does not fall apart and its structure remains dense. The presence of strongly intertwined physiologically active roots in the third horizon of the litter is evidence of the activation of microbiological processes, which are also accelerated by the interception of moisture and the accumulation of humus particles of the soil by the lower layers of the forest litter. To prevent the development of flood processes, the effective performance of water regulation and water purification functions, it is recommended to create water conservation plantations with the formation of the identified type of forest litter

Oil and gas bearing potential of crystalline basement in Dnieper-Donets Basin – unbiased view

Purpose. Based on the analysis of existing information on the exertions of oil and gas in crystalline rocks of the Dnieper-Donets Basin (DDB), assess the presence of hydrocarbon deposits in certain fields and assess the prospects for the discovery of new ones. Methodology. The study on oil and gas bearing capacity of the crystalline basement was based on the analysis of stock material on oil and gas fields of the Dnieper-Donets Basin, the study on petrographic composition of rocks in sections, analysis of results of well logging, petrophysical studies on rock samples from promising intervals of wells. The peculiarities of the structure of structural-tectonic models of hydrocarbon deposits with oil and gas exertions in the upper parts of the crystalline basement were also taken into account. Findings. A significant number of drilling and well testing results, lithological-petrographic and petrophysical studies were analyzed, which allowed making objective conclusions about the existence of independent oil or gas deposits in the weathering crust of the crystalline basement at already known deposits. The conclusions also concerned the assessment of the industrial (commercial) attractiveness of the discovered deposits or oil and gas exertions in the upper parts of the crystalline basement of the DDB fields. Originality. At the current level of study, it can be argued that within the Eastern Ukrainian oil and gas basin in the Archean-Proterozoic traps apart from the basal horizons of the cover, oil deposits were found in only three fields: Yuliivske, Ulianivske and Hannivske. Undoubtedly, there are hydrocarbon deposits in the Precambrian formations of DDB, but the most extensive discoveries in this direction of exploration and involvement in the development of already discovered accumulations seem to be still ahead. The geological situation should be realistically assessed for the presence of potential areas where the existence of common hydrocarbon deposits in the weathering crust of the foundation and the lower horizons of the sedimentary cover in the DDB is possible. Practical value. The main value of this study is the real assessment of the existence of industrial accumulations of hydrocarbons in already discovered oil and gas fields in DDB. The myth of the presence of many oil and gas deposits in DDB in crystalline rocks of the crystalline basement, which without proper justification has repeatedly been found in the professional literature and in scientific reports at specialized conferences of various levels, has been debunked. Certain prospects for the discovery of oil and gas deposits in the crystalline basement of the Dnieper-Donets Basin are unmarked.

Characterization, classification, and suitability evaluation of some soils in the floodplains of River Niger, Kogi East, Nigeria for rice, maize, cassava, and oil palm production

This study was conducted to characterize, classify and evaluate four soils along River Niger in Kogi East for rice, maize, cassava and oil palm production. The soils developed predominantly from alluvium. The soils were located in four communities namely Ejule-Ojebe, Shintaku, Bagana and Kpata all in the floodplains of River Niger in Kogi East. The soils were investigated using a free survey technique. Four pedons representing four soils located at different sites in the floodplain were studied. The environs and the profiles of the soils were described according to standard field procedures. Soil samples were then taken from genetic horizons for laboratory analysis. The soils were also characterized and classified according to Soil Taxonomy and the World Reference Base for Soil Resources (WRB). The colour of the soils ranged from shades of brown to grey generally due to poor drainage. The soils also varied in depth and horizonation due to differences in profile development. Due to the relatively higher sand content of the soils, especially in the surface and subsurface horizons, the texture of the soils generally ranged from sand to clay loam. The pH (H2O) of the soils ranged from 4.8 to 7.3, strongly acidic to slightly alkaline, and tended to increase with depth. The soils containedmoderate amounts of organic carbon in the surface soils but lower levels in the lower horizons. Based on their properties, the soils were classified according to Soil Taxonomy as Alfisols (Ejule-Ojebe), Entisols (Shintaku), Inceptisols (Bagana) and Alfisols (Kpata) and according to WRB as Planosols, Arenosols, Gleysols and Planosols, respectively. The soils were found to be highly suitable for rice production but moderately suitable for maize, cassava and oil palm. Apart from rice cultivation, wetness of soil was found to be the major limiting factor for optimum rainfed cultivation of maize, cassava and oil palm.

First pterosaur from the Early Cretaceous Huajiying Formation of the Jehol Biota, northern Hebei Province, China: insights on the pedal diversity of Pterodactyloidea

ABSTRACT As the lowest horizon of the Early Cretaceous Jehol Biota, the Huajiying Formation of the northern Hebei Province, China is rich with avians and feathered dinosaurs, but lacks pterosaur record. Here the first pterosaur fossil is reported from the Huajiying Formation. The new pterosaur specimen is characterised by an unusual pedal configuration of a short and spread metatarsus with elongate digits, showing a close resemblance to the dentulous Ornithocheiroidea. The pedal configuration is diverse in pterosaurs, and is often associated with ecological adaptations. In contrast to the general pattern of the elongate metatarsus and short digits, the elongate digits of the dentulous ornithocheiroids (e.g., boreopterids and istiodactylids) might offset the shortened metatarsus to enlarge the pedal surface for paddling, representing a new strategy in adaptation to the aquatic environment.

Material-Balance Method With Static Modeling Helps Generate Reliable Forecasting

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 207933, “The Integration of Analytical P/Z Material-Balance Method With Static Modeling and Integrated Asset Model To Generate Reliable Forecasting for a Giant Onshore Gas Field in Abu Dhabi,” by Bondan Bernadi, Yuni Budi Pramudyo, and Fatima Omar Alawadhi, ADNOC, et al. The paper has not been peer reviewed. Reliable field gas initially in place (FGIIP) estimation is achieved by performing multiple reservoir-pressure/gas-compressibility (P/Z) calculations. Several scenarios are developed in the complete paper by defining key areas based on permeability variation, areal distribution, and pressure/volume/temperature (PVT) behavior. The best FGIIP estimation is then fed back into the static model to generate numerous realizations considering the static uncertainties to produce the same FGIIP. A giant onshore gas field is highly heterogeneous, with permeability, lateral composition variation, and dynamic interaction between wells. Incorporating the correct estimation of FGIIP into the integrated asset model (IAM) has helped yield reliable forecasting and has enabled more-efficient field development. Introduction Reservoir A produces onshore from a limestone formation in the lower cretaceous horizon. The structure is a simple dome that is somewhat steeper on the eastern flank, with two extended noses in the south and southeast directions. The total thickness of this zone decreases down the flanks but more rapidly in the northeast direction. Formation porosity is in the range of 10 to 25%, with a permeability range of 0.5 to 88 md. The original reservoir pressure is approximately 4,300 psia, with a reservoir temperature of 260°F. The field has been producing in depletion mode for more than 30 years, flowing into one common surface network with other depletion reservoirs. More than 100 wells had been drilled in the gas-cap zone, with an average gas-production rate of 15–20 MMscf/D per well. Because of the depletion scheme applied since the beginning of field life, gas-production decline is inevitable. The focus of the complete paper mainly relates to the gas-cap zone.

Neoformation of palygorskite in Calcids of Central Iran

Palygorskite has been reported in alluvial sediments and in soil clays in Central Iran, but it is not known if it is inherited or formed in situ. Here, we sampled Calcids developed from Triassic and Cambrian dolomitic formations in the southwestern part of Yazd and performed soil and clay characterization by X-ray diffraction and fluorescence, optical and scanning electron microscopy and energy dispersive X-ray spectrometer analyses. Our results suggested palygorskite neoformation in the calcic soil horizons in Calcids. The soils with aridic soil moisture regime and high Mg concentration, during the formation of a calcic horizon by precipitation of secondary calcite, conditions were suitable for authigenic palygorskite crystals of long size (>10–20 μm) and their stability. In addition, the occurrence of short-size (about 2 μm) palygorskite fibers in the lower gypsic horizon probably resulted from its translocation from the upper horizons. Therefore, such results suggested palygorskite neoformation in the calcic soil horizons in these Calcids of Iran.