SAMARA CITY UNDERGROUND URBANIZATION DEVELOPMENT AND ITS CONSEQUENCES

Nowadays the area of cities is almost everywhere increasing - the territory urbanization is developing. At the same time, due to lack of land resources, the underground space development intensifi es, and the underground construction volume increases, i.e., underground urbanization takes place. This process has undoubtedly positive results, as it can help solve territorial, transport, environmental and other problems of cities while preserving the unique appearance of buildings in the historical centers of cities. At the same time, some engineering and geological processes may be activated as a negative underground urbanization result. The article deals with underground urbanization history in Samara and defi nes its main stages. More than one million people live in Samara city, subway line was built, there are subway objects of industrial and defense importance (bunkers) reaching considerable depth. Active underground construction can lead to geological processes strengthening (weathering, karst formation, suff osia, etc.), change of strength properties of rocks, violation of natural hydrological regime of the territory. The territory of Samara has an inhomogeneous geological structure and complex engineering and geological construction conditions. Seven engineering-geological districts have been identifi ed and studied, on the territory where underground construction development can lead to diff erent, including negative, consequences.

Material Composition of the Mesozoic Alkaline Rocks of the Yukhta Massif (Southern Yakutia, Central-Aldan Ore Region)

The paper considers the petrographic composition of the Mesozoic alkaline igneous rocks of the Yukhta massif. It is part of the Central Aldan ore region and is spatially located in the central part of the Nymnyr block. The massif is a large multiphase structure, of the most productive stage of the territory’s development – the Mesozoic tectonic-magmatic activation of the Aldan-Stanovoy shield. Determination of the qualitative quantitative-mineralogical characteristics of the 2 and 3 phases of intrusion (emplacement) most promising for gold-radioactive mineralization with the help of crystal-optical methods was the main goal of this work. As a result of petrographic studies of Mesozoic alkaline igneous rocks, it is defined that, the Yukhta massif is a multiphase magmatic structure, with decrease of the content of dark-colored minerals in rocks from the early to later phases of intrusion. In general, the rocks of the massif bear significant traces of secondary changes, which are related to the gradual formation of the massif. According to the features of the composition of the massif rocks, it was found that the latter could be formed from residual differentiates during the fractional crystallization of rock-forming minerals with the involvement of plagioclases. The Yukhta massif is associated with the large Samolazovskoye gold deposit, which formation is related to an intense contact-metasomatic impact on carbonate rocks. Hydrothermal-metasomatic transformations of the latter are the products of multi-stage silica-alkaline metasomatosis associated with the second and especially with the third phases of the massif intrusion, and with further weathering processes, involving karst formation, disintegration of gold-ore metasomatites and the formation of a thick oxidation zone. From whence it is concluded that uranium being a chemically active element does not accumulate in a hypergenic form within the Yukhta massif. Where the weathering crust is intensively developed, a gold-ore type of mineralization is observed. On the other hand, the rocks of the massif itself, in particular syenites of the 2 and 3 phases of intrusion, may be promising for the uranium-thorium-rare earth (U-Tn-REE) type of mineralization. In general, these studies in this direction will provide insight into a number of issues related to the study of the evolution and metallogeny of the Mesozoic tectonic-magmatic activation of the Aldan-Stanovoy Shield

Diversity of cave-dwelling bats in Leang Londrong, Bantimurung-Bulusaraung National Park: An initial field note

Leang Londrong is one the caves in Maros-Pangkep Karst Formation utilized for nature tourism and has become a habitat for bats. Little is known on the bats inhabited the cave. Therefore, this study is aimed to investigate the diversity, abundance, morphometric of cave-dwelling bats in Leang Londrong, Bantimurung-Bulusaraung National Park as well as their distribution of roosting sites and micro-climate conditions between May-June 2021. The bats were trapped and collected by using two-layered mist nets erected in front of cave entrance. With captured-marked-recaptured (CMR) method, bat diversity, abundance, and morphometric, were examined. Direct measurements on roosting sites were employed to determine micro-climate conditions. There were 3 species of Microchiropteran bats found in the site namely Rhinolophus arcuatus, Hipposideros diadema and Myotis sp. Total number of all bats trapped in the net during the observation days was 10 individuals. The largest bat species found living in the cave was Hipposideros diadema (average body length of 101.1 mm; tail of 51.46 mm; ear 24.5 mm; forearm length of 96.12 mm; tibia length of 34.6 mm; hind foot of 14.32 mm; and 63.75 g of weight). Meanwhile, Myotis sp. was known to be the smallest. For micro-climate conditions, the five roosting sites inside the cave had the average temperature of 26.58°C (range: 26.2-27.3) with the humidity in average around 92.88% (range 89.6-93.8%), while the average light intensity was found to be 0 lx in each roost with the noise level recorded in average of 65.08 dB.

Simulation the deformation and damage of a rock massive containing a cavity

Карстовые проявления широко распространены во многих регионах и представляют значительную опасность для проживания и хозяйственной деятельности. Воронки возникают при обрушении горных пород над подземными пустотами (пещерами, выработками и т.д.), образовавшимися при карстовом процессе или в результате антропогенного воздействия в массиве горных пород. Однако не каждая карстовая или техногенная полость приводит к разрушению земной поверхности, и, как правило, ее возникновение является неожиданным. В данной работе рассматривается динамика формирования провалов земной поверхности в виде карстовой воронки. Для этого с помощью бессеточного метода сглаженных частиц (SPH) решается геомеханическая задача. Выбранный численный метод позволяет получить решение задачи с учетом больших деформаций и возможных разрушений в процессе изменения напряженно-деформированного состояния. Используется критерий разрушения Друккера-Прагера, параметры которого со временем меняются в соответствии с накоплением повреждений, которые определяют временное развитие процесса разрушения, его начало и скорость. Karst manifestations are widespread in many regions and pose a significant danger to residence and economic activity. Failing funnels arise during the collapse of rocks over underground voids (caves, workings, etc.), formed during karst formation or in the process of anthropogenic doing in the rock massive. However, not every karst or technogenic cavity gives rise to a failure of the earth’s surface, and as a rule, its occurrence is unexpected. In this work, we consider the dynamics of the formation of dips of the earth’s surface in the form of a collapse pipe. To do this, the geomechanical problem is solved by the meshless code Smoothed Particle Hydrodynamics (SPH). The method allows to obtain a solution to the problem taking into account large deformations and possible discontinuities in the process of changing the stress-strain state. The Drucker-Prager fracture criterion is used, the parameters of which change over time in accordance with the accumulation of damage, which determines the temporary development of the fracture process, its beginning and speed.

Geochronology and Stable Isotope Analysis of Fracture-Fill and Karst Mineralization Reveal Sub-Surface Paleo-Fluid Flow and Microbial Activity of the COSC-1 Borehole, Scandinavian Caledonides

The deep biosphere hosted in fractured rocks within the upper continental crust is one of the least understood and studied ecological realms on Earth. Scarce knowledge of ancient life and paleo-fluid flow within this realm is owing to the lack of deep drilling into the crust. Here we apply microscale high spatial-resolution analytical techniques to fine-grained secondary minerals in a deep borehole (COSC-1) drilled into the Silurian-Devonian Scandinavian Caledonide mountain range in central Sweden. The aim is to detect and date signs of ancient microbial activity and low-temperature fluid circulation in micro-karsts (foliation-parallel dissolution cavities in the rock) and fractures at depth in the nappe system. Vein carbonates sampled at 684 to 2210 m show a decreased C isotope variability at depths below 1050 m; likely due to decreased influence of organic-C at great depth. Micro-karsts at 122–178 m depth feature at least two generations of secondary calcite and pyrite growth in the voids as shown by secondary ion mass spectrometry analytical transects within individual grains. The younger of these two precipitation phases shows 34S-depleted δ34Spyrite values (−19.8 ± 1.6‰ vs. Vienna-Canyon Diablo Troilite (V-CDT)) suggesting microbial sulfate reduction in situ. The calcite of this late phase can be distinguished from the older calcite by higher δ18Ocalcite values that correspond to precipitation from ambient meteoric water. The late stage calcite gave two separate laser ablation inductively coupled mass spectrometry-derived U-Pb ages (9.6 ± 1.3 Ma and 2.5 ± 0.2 Ma), marking a minimum age for widespread micro-karst formation within the nappe. Several stages of fluid flow and mineral precipitation followed karst formation; with related bacterial activity as late as the Neogene-Quaternary; in structures presently water conducting. The results show that our combined high spatial-resolution stable isotope and geochronology approach is suitable for characterizing paleo-fluid flow in micro-karst; in this case, of the crystalline crust comprising orogenic nappe units.

Features of formation of karst falls on the earth’s surface

Karst manifestations are widespread in many regions and pose a significant danger to residence and economic activity. Failing funnels arise during the collapse of rocks over underground voids (caves, workings, etc.), formed during karst formation or in the process of anthropogenic doing in the rock massive. However, not every karst or technogenic cavity gives rise to a failure of the earth’s surface, and as a rule, its occurrence is unexpected. In this work, we consider the dynamics of the formation of dips of the earth’s surface in the form of a collapse pipe. To do this, the geomechanical problem is solved by the meshless code Smoothed Particle Hydrodynamics (SPH). The method allows to obtain a solution to the problem taking into account large deformations and possible discontinuities in the process of changing the stress-strain state. The Drucker-Prager fracture criterion is used, the parameters of which change over time in accordance with the accumulation of damage, which determines the temporary development of the fracture process, its beginning and speed. Various options for the formation of a vertical dip are considered depending on the geometrical parameters of the initial cavity, its depth and materials composing the rock mass, as well as the features of the destruction of various materials composing the mass during the formation of the dip. Relations are obtained that relate the depth of the cavity, the horizontal size of the hole, the strength properties of the rocks (adhesion, angle of internal friction), the coefficient of lateral pressure in the array. The features of wave processes generated by the formation of a dip are considered, for which a velocity field is obtained near the fracture zone at various time points in the fracture process.

Carst Marble on Tyrnyauz Deposit

The karst of marbles is considered as the least studied type of karst. Here we have pinpointed the karst area of the ore field of the Tyrnyauz deposit. Lithological and petrographic characteristics of the skarned marbles of Tyrnyauz are given, their chemical activity is determined. Tectonogenic fissure-karst drainage system of the deposit is analyzed. The main factors of karst formation have been determined and the development of the karst marbles of the Tyrnyauz ore field at various depths is predicted.

Six new species of the Cyrtodactylus intermedius complex (Squamata: Gekkonidae) from the Cardamom Mountains and associated highlands of Southeast Asia

An integrative taxonomic analysis using color pattern, morphology, and 1449 base pairs of the ND2 mitochondrial gene and its five flanking tRNAs demonstrated that eight species-level lineages occur within the Cyrtodactylus intermedius complex (Cyrtodactylus intermedius sensu stricto, C. phuquocensis and related populations) of the Cardamom mountains and associated highlands that have a sequence divergence ranging 3.4–8.9%. Additionally, each lineage is discretely diagnosable from one another based on morphology and color pattern and most occur in specific geographic regions (upland areas, karst formations or islands) that prevent or greatly restrict interpopulation gene flow. Six of these lineages were masquerading under the nomen C. intermedius and are described as the following: Cyrtodactylus auralensis sp. nov. endemic to Phnom Aural, the highest mountain in Cambodia; C. bokorensis sp. nov. endemic to the Bokor Plateau, Cambodia; C. cardamomensis sp. nov. from the main block of the Cardamom mountains; C. thylacodactylus sp. nov. endemic to Phnom Dalai the northernmost peak of the Cardamom mountains; C. laangensis sp. nov. endemic to the Phnom Laang karst formation, Cambodia; and C. septimontium sp. nov. from the Bảy Núi Hills of southwest Vietnam.

APLIKASI METODA RES-2D UNTUK EKSPLORASI AIR BAWAH TANAH DI DAERAH KARS

People have long been interested in kars, the typically topograhy in limestone area. There are many spectacular ornament in the caves caused by carbonates presipitates. Among the most common shapes which is be chief attraction for cave visitors is stalactites, stalagmites and columns. Beside of the excitements, kars also have hard problem for people who lived in that area. It is how to find out water for their living. Karst formation, both the surface (dolina, hill, etc) and underground forms (caverns, groundwater conduits, underground streams), appears as conductive zones relative to adjacent undisturbed limestone. Therefore resistivity methode will produce good results if applied to identify dolina, conduits , caverns and structure of geology in kars. The methode describes in this paper is Res-2D with configuration of pole-dipole with area for research are kars in Pacitan and Tulungagung region. Four principal layers can typically be differentiated in a vertical section : near surface (clayey) loam and soil in dolina, dry karstified limestone, conduit cave and solid unkarstified limestone. They have contrast of resistivity. Conduits have resistivity value range from 10 to 20 ohmm, whereas resistivty of cave is 1000 ohmm. Karstified limestone have resistivity value from 20 to 250 ohmm, whereas massive limestone have resistivity 250 ohmm. This paper shows that Res-2D methode can give good contribution in exploration of groundwater in kars area. Kata Kunci : Kars, Res-2D, Conduits