Trace elements characterization of soils and rocks in Agricultural areas of Labunwa, Near Idanre, Southwestern Nigeria

Trace elements (TE) concentrations of subsoil and the underlying parent rocks of Labunwa – Odele area were determined in other to ascertain the enrichment level, distribution and sources of these TEs in the subsoil in the study area. Twenty-one (21) subsoil (at depth of 30 -100 cm) and thirteen (13) rock samples were collected, pulverised and digested using aqua regia for soil samples and near total digestion of HClO4, HF, HCl and HNO3of different proportions for the rocks. The samples were analysed using Inductively Coupled Plasma- Mass Spectrometry, (ICP-MS). The mean TE concentrations in ppm for subsoil showed Cu (40.0), Pb, (24.2), Zn (56.3), As (0.9) and U (2.7) among other elements as against the mean concentrations of granite gneiss (GGN) with Cu (22.9), Pb (61.4), Zn (64.6), As (1.0), U (2.6) and Pegmatite, (PGM) Cu(128.4), Pb(17.0), Zn(108.8), As (1.1), U (1.3) among other TEs. The relatively low concentrations of the TEs in the subsoil compared to the underlying parent rocks suggests that TEs in the subsoil may have been influenced by geogenic factors, such as weathering of the underlying rocks. TEs source apportionments in the subsoil using Bivariant plots, correlation coefficient, Bi-polar and dendogram analyses showed that these TEs are essentially from the underlying GGN and PGM in the area. Pollution status indices, I-geo, Contamination factor and PLI showed that the study area is practically unpolluted. This suggests that locations with relatively higher concentrations of some TEs are probably due to mineralisation and since most of the subsoil TEs are significantly lower in concentrations compared to the underlying bedrock, the area is safe for agricultural activities.

SOME ASPECTS OF POLISH-UKRAINIAN GEOLOGICAL AND GEOMORPHOLOGICAL RESEARCHES OF WESTERN VOLYN-PODILLIA DURING THE POLISH INVASION

The proposed article is based on an analysis of publications on field observations published in the then Polish and Ukrainian periodicals, collections of materials from scientific forums at various levels, works collections of individual Polish and foreign scientific institutes, etc. The purpose of the article was an attempt to analyze and generalize the research results of the study area in the field of Quaternary geology and geomorphology. It should also be noted that publications from the listed sections of physical geography are encountered quite sporadically and in significantly smaller numbers than articles on purely geological disciplines such as mineralogy, petrography, lithology, tectonics, etc. The study of geological and geomorphological objects and processes was carried out on the territory of Western Volyn-Podillia, which at that time was a part of the Polish-Lithuanian Commonwealth. The works mainly concerned the study of the stratigraphy of anthropogenic sediments distributed in the Podillia loess and loess soils, continental glaciations and related glacial and fluvial-glacial deposits, surface and underground karst, etc. It was established that significant in volume and depth of generalization of works on the geological and geomorphological structure the region features at that time was not. The studies that were carried out were not systematic, they were often carried out on the researchers initiative and without adequate funding, with localization mainly in the territory with open at that time deposits of certain minerals types. Analysis of publications can be stated as follows: the study of Quaternary deposits of the region and loess in particular was carried out with extensive use of laboratory studies, paleontological method, chemical, particle size distribution mineralogical and petrographic analyzes, the method of separation of loess minerals in heavy liquids, paleontological and archaeological observations, etc., were progressive at that time. It should be noted that individual reports on the determination of the age of the Quaternary strata were poorly synchronized with each other and a reliable generally accepted scale for the division of these deposits in this period was not agreed. During this period, factually substantiated schemes of geomorphological zoning of both the Podillia region as a whole and its individual components were proposed. Regular relationships of the relief features of the region with the lithogenic base, neotectonic movements, glacial and fluvial-glacial processes are traced. Significant progress is noted in the study of stratigraphy, lithology of local loess strata, problematic issues of their genesis are discussed. Among the few works on the study of the loess cover of Volyn-Podillia, the work of Yu. Polianskyi and Yu. Tokarskyi attracts attention first of all. The works on the study of loess are important due to: a) their almost ubiquitous distribution in the described territories; b) value for stratigraphic subdivision of the Pleistocene; c) controversial genesis; d) widespread use for the production of bricks and tiles. Work on the study of surface and underground forms of the Podillia karst has spread. Systematic mapping of individual underground cavities begins which gave impetus to their use in the future as objects of tourism. The largest number of works is devoted to the problems of studying the relief and modern physical and geographical processes in the interwar period. At the same time, along with purely descriptive publications, works appear where conclusions are based on the use of cartographic materials, which allowed researchers to identify significant patterns in the morphological features of the region. In the period under study, numerous publications by soil scientists also appeared, in which Quaternary sediments are considered as parent rocks on which soils were formed, the dependence of the type of soil on the lithology of the underlying rocks is established. In general, the works of Polish and Ukrainian researchers in the characterized period laid a reliable foundation for modern ideas about the geological and geomorphological features of the region. Keywords: geomorphological studies, Quaternary deposits, glacial deposits, stratigraphy, morphology, loess deposits.

Insights on the Origin of Vitrified Rocks from Serravuda, Acri (Italy): Rock Fulgurite or Anthropogenic Activity?

In this study, twenty five partially vitrified rocks and four samples of vitrified rocks collected on the top hill called Serravuda (Acri, Calabria, Italy) are analyzed. The goal is to shed light on the origin of these enigmatic vitrified materials. The analyzed vitrified rocks are a breccia of cemented rock fragments (gneiss, granitoid, and amphibolite fragments) which extends for more than 10 m, forming a continuous mass along the northern and north-west border of the flat top hill. Surrounded by the vitrified accumulation, exposed Paleozoic granitoid substrate rocks show limited melting or heat-alteration processes. By mapping minerals embedded in the glass matrix via X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM), an interpretation of source rock material, reactions, and thermometric indications to form vitrified materials on the top hill of Serravuda, Acri (Italy), is provided. The mineralogical composition of heated or partially vitrified samples is heterogeneous owing to the effects of heating events, but it mostly recalls the parent rock composition (gneiss, granitoid, and amphibolite). The presence of quartz, cristobalite, tridymite, mullite, plagioclase, hercynite, cordierite, and olivine in Serravuda partially vitrified rocks and glasses suggests that samples were subjected to pyrometamorphism and the temperature range at which the glass formed was about 1000–1100 °C in the presence of hydrous gas, burning organic material (e.g., wood), and assuming thermodynamic equilibrium. Lithologies of the heated or partially vitrified rock fragments are a mixture of parent rocks not outcropping on the top of the hill such as gneiss and amphibolite. Data suggest that Serravuda vitrified rocks are most likely the result of anthropic activities and could represent remnants of vitrified fort walls. The mineral assemblage of partially vitrified rocks and glasses suggests that the fort walls were made of slabs derived from the local metamorphic rocks with the addition of Serravuda substrate Paleozoic granitoid rocks to improve the strength and insulation of the fort walls.

Study of the diversity and mapping of xerophytic vegetation of the southeastern coast of Crimea peninsula using remote sensing data

The study of diversity and ecological-phytocenotic mapping of the vegetation cover was carried out at the key area located in the eastern part of the Echki-Dag mountain range in the territory of the Lisya Bay Reserve (Eastern Crimea). A generalization of the classification and ecological patterns of vegetation was carried out to create a legend for a large-scale ecological-phytocenotic cartographic model (at the scale of 1:10000). The ecological-geomorphological series and combinations of xerophytic and mesoxerophytic plant communities indicating erosion-denudation processes on different substrates of the underlying parent rocks were the thematic basis of the cartographic model. The developed legend is based on the units of vegetation of the association rank obtained using the Braun – Blanquet method combined into ecological series in accordance with their position on the gradients of the leading ecological factors as well as on the hierarchy of phytochories determined by the categories of erosion-denudation relief of coastal slopes. The resulting vegetation map demonstrates the main regularities of the regional phyto-diversity and serves as the basis for assessing the resource potential of vegetation, its landscape-stabilizing and nature conservation value.

Critical raw materials enrichment in bauxite laterite: a case study of diverse parent rock types

High demand in utilizing the mineral and metal for industrial manufacture, which is unequal to the resources, has caused a vulnerable disruption. To compensate stocks in the global market, exploration of raw materials should be carried out for by-products. This study aims to elucidate the enrichment mechanism of Sc, Ga, and Nb elements from the bauxite weathering profile and sediment residue. An observation has been conducted using petrography, mineragraphy, x-ray fluorescence spectroscopy (XRF), x-Ray diffraction (XRD), inductively coupled plasma combined with mass spectrometry (ICP-MS), and scanning electron microscope - energy dispersive spectrometry (SEM-EDS). The results indicate that bauxite ores (gibbsite) hold the metal compounds of Ga, while some iron minerals of goethite and hematite are present as Sc-bearing minerals, and Nb is highly concentrated within saprolite of bauxite. The maximum enrichment of Ga and Sc is observed from the bauxite sample and sediment residue derived from microdiorite pyroxene, which makes up 24.2 - 42.1 ppm and 39.9 - 55.4 ppm, respectively. By contrast, Nb enriched about nine-fold higher in the saprolite zone relative to bauxite produced by weathering of granitic parent rocks. It suggests that metal concentration in the lateritic products depending immensely on the precursor rock types.

On frozen chernozem genesis and evolution at lacustrine plains in the southern Vitim plateau (Eastern Siberia, Russia)

To clarify the probable role of the stage of the post-lake soil in the evolution of clay-illuvial frozen chernozem the studies were carried out in the southern Vitim plateau of Transbaikalia. The research covers soils in the area of ancient currently dried lakes and the lakeside plain of the Yeravninskaya depression. The obtained data evidence the dissimilarity of parent rocks, as well as radical differences in the soils’ characteristics and properties.

Soils of mountain floodplains in the zone of tectonic joints of Mongol-Okhotsk Orogenic Belt (Mongolia)

New data on the soils of mountain floodplains in the tectonic joints zone of the Mongol-Okhotsk Orogenic Belt on the example of the Upper Kerulen Basin are presented. Soil diversity is mostly determined by sedimentation conditions and drainage of the parent rocks. There are alluvial–humus (Fluvisol (Humic)), mucky–humus (Folic Fluvisol), dark–humus (Fluvisol (Mollic)), dark–humus gley (Gleyic Fluvisol) and dark–humus saline soils (Sodic Gleyic Fluvisol (Mollic)) were diagnosed. Tectonic movements of the earth’s crust lead to the appearance of shaftlike linear dams, blocking river flow through the valley. So, the Kerulen river changed the direction of the channel and go beyond the depression, embedding into its mountain frame. Current seismicity impact on soils appears locally at tectonically active positions of epigenetic areas, close to outputs of saline underground deep waters, in the form of surface soil salinity and hydrometamorphism.

Features of filling reservoirs with hydrocarbons in the territories with a low maturity of the oil and gas parent rocks (a case study of Jurassic hydrocarbon traps in the Uvat district)

The article is devoted to the results of an analysis of geological factors that had a great influence on the filling of Jurassic traps with hydrocarbons. Based on the results of paleotectonic analysis, three key stages of reconstructions of the structural plans of sedimentary cover deposits were identified. Each stage was characterized not only by the appearance of new traps in the interval of Jurassic deposits, but also by the sinking of rocks of Bazhenov formation to a certain depth. It is revealed that in most of the territory of the Uvat district, Bazhenov formation didn't have time to fully realize its hydrocarbon-generating potential. In the Central and Eastern regions it entered the main zone of oil formation only in the Paleogene. Since the development of the relief of modern structural plans of Jurassic deposits in this area occurred in several stages, both the formation of traps and the lateral migration of hydrocarbons also occurred in stages. The first stage of migration occurred at the boundary of the lower and upper Cretaceous, the second stage occurred at the beginning of the Paleogene. As a result, the combined influence of lateral migration of hydrocarbons and the gradual formation of local structures in different areas of the Uvat district led to selective filling of Jurassic hydrocarbon traps.