Geological and geomorphological studies for projecting the “ Orilskyi ” national geopark

Доказана необходимость создания Орельского национального природного парка как наиболее универсальной и одной из наиболее эффективных форм организации природоохранных территорий в регионе. Исследована территория по всем критериям соответствует статусу национального природного парка. Проблему проектирования национального природного парка «Орельский» рассмотрен в контексте признания геологической среды как важной составляющей окружающей среды, достойной защиты и сохранения как объекта геологического наследия не менее, чем любой компонент природно-заповедного фонда (ПЗФ). Обоснована необходимость проведения геологических и геоморфологических исследований при проектировании не только выдающихся с точки зрения геологии объектов ПЗФ, но и таких, что при плохой видслонености характеризуются интересной и неповторимой историей геологического развития, своеобразием проявлений различных геологических процессов и явлений. Выявлены и проанализированы особенности тектоники и неотектоники территории проектируемого парка, которыми обусловлена как глубинное строение региона так и особенности современного рельефа, возникшие за их действия. Установлен четкий закономерная связь между понятиями «биоразнообразия» и «георизноманиття». Впервые отмечается, что Орельский национальный природный парк это важное природное ядро экосети национального значения, расположенный на перекрестке двух важнейших транснациональных экокоридоров Панъевропейской экосети - Днепровского меридионального и Украинского степного широтного, а также он являетсяглавной частью межрегиональной соединительной территории между левобережным Надднепрянским лесостепи и степи и между бассейнами Днепра и Северского Донца.

Introduction.National parks are the most universal and one of the most efficient forms of organizing nature reserves in the world.National parks provide all necessary opportunities for realizing the following strategically important tasks: providing efficient protection for natural ecosystems, landscape diversity, biological and geological diversity across large territories; creating conditions for development of sustainable tourism (socially responsible tourism); support for forms of farming which are friendly to the environment and wildlife; preservation of historical and cultural heritage and cultural traditions of local communities.A national park is a protected natural territory, which has natural complexes and objects not significantly affected by anthropogenic pressure.The species of plants and animals inhabiting a park, together with their environment have a specific scientific value.Usually, national parks cover large territories in picturesque areas.Work is carried out to restore their landscapes, rare and endangered species of plants and animals and also objects of geological heritage are preserved there.Unlike strict nature reserves, national parks are partly open for regular visits by tourists, recreation and ecological education.A national park is a territory which is a state property and which has restricted economic activity for the purpose of preserving the natural environment (Natsionalnyi pryrodnyi, 2016).
In total, there are 2000 national parks in the world, their territory covers 2% of the Earth`s land area.Since 1980, national parks projects have been created in Ukraine, which now has 47 national parks.More than half of them were created during the period from 2009 to 2011.During that last wave of organizing national parks, Dnipropetrovsk oblast also had great chances of opening at least one national park in the valley of the Oril river.The main positive precondition for this was the appearance of the first scientific grounding for the project, developed by the non-governmental organization "Orlan".Its activists had already conducted a large amount of scientific research and educational excursions in the basin of the Oril river in the late XX -early XXI centuries (Domrachev, 1999).Using the results of these expeditions, the significant nature conservation value of the valley of the Oril river was revealed, and the first scientific grounding for creating a national park in Dnipropetrovsk oblast was laid (Vad.Manyuk, Vol. Manyuk and Chegorka, 2010;Vad. Manyuk, 2016).On the basis of this research, from 2001 the State Administration of Protecting the Natural Environment initiated the design of cartographic materials for further projecting of the national park, and also provided suggestions to the Ministry of Environmental Protection of Ukraine to include the question of creating the Orilskyi National Park into the list of tasks of the state programme of forming a national ecological network.
At that time, in Europe, an organization was being formed, the establishment and further activity of which would justify the significance of preserving not only wildlife, but also inanimate nature, i.e. the geological environment with the full diversity of its components (Vol.Manyuk, 2015Manyuk, , 2016)).Such an organization, recognized all over the world, is the European Association for the Conservation of the Geological Heritage (ProGEO).Its first international symposium was held in Digne, France, in 1991(Vol. Manyuk, 2006).The convention of a special working group, which was held with the support of UNESCO, approved the historical "Declaration of the Rights of the Memory of the Earth".In 1995, Ukraine joined ProGEO, contributing to successful realization of some important ideas written in the Declaration.In particular, when acknowledging the need for creating a national park in Dnipropetrovsk oblast, the geological structure and peculiarities of the landscape were for the first time seriously considered as important components of the natural environment (Vad.Manyuk et al., 2010).During the composition of the "Programme for Forming a National Ecological Network in Dnipropetrovsk Oblast for 2003-2015", in contrast to many other oblasts, not only biodiversity, but also geodiversity was considered: "Preserving the full diversity of natural and semi-natural landscapes, populations of local flora and fauna, geological relics, diversity of natural soils and restoring populations of rare and endangered species of biota in the region" (Vad.Manyuk, Vol. Manyuk and Obuhova, 2003).Since then, any work towards designating a territory as an object of the nature-reserve land and further processes according to "Programme of Ecological Network" has been followed up by professional geological and geomorphological studies with corresponding cartographic and text materials.For examples of completed reserve projects we can mention the following: the Marianivsko-Kulebivskyi reserve, dishes Levshynskoho, Chornecha, Tatarka, Zhitlova, Rekalova, Zmiina, Kobylna; areas along the rivers Bazavluk, Mokra Sura, Saksahaniia, and many others (Fig. 1,2).But, unfortunately, the process of forming the park was delayed for an unspecified period of time, and after 2001-2002, for the second time, the question arose only in 2008, along with the start of the social process of forming networks of new national parks all over Ukraine.At that time, the President of Ukraine signed a number of decrees in order to advance the process and ensure full support from state institutions for measures for creating national parks.One of those decrees also mentioned the Orils`ky National Park in Dnipropetrovsk oblast as a top-priority object (Ukaz Prezydenta, 2008).
Unfortunately, due to lack of financing on one hand, and some opposition by particular regional institutions on the other hand, the National Park failed to open at that time.Only beginning with 2015, due to constant attention from the ecological and scientific community, and support from the Department of Environmental Protection in Dnipropetrovsk Oblast State Administration, did the Oblast Council allocate the necessary costs for carrying out the project of creating the park, which included detailed scientific grounding, a set of cartographic materials and the materials of agreement according to the requirements of the current legislation for creating national nature parks in Ukraine.
In order to implement the project, during July-November of 2015 a scientific group was formed and a complex study of the entire territory of the Oril river in Dnipropetrovsk oblast and certain adjacent areas in Kharkiv and Poltava oblasts was conducted.On the one hand, the study discovered many new areas with rare and relic ecosystems, populations of rare animals and plants, included in The Red Book of Ukraine and other red lists (including some species, which had not previously been recorded for the Oril river valley).These areas are especially interesting from a scientific point of view and especially significant from a nature protection point of view.A number of interesting botanical natural relics was discovered, a number of new or yet unstudied outcrops of rocks was found, which adds new elements for understanding the geological history of Pryorillia.On the other hand, the study found substantial evidence of massive damage caused to the integrity of natural ecosystems or their total destruction following harmful illegal and uncontrolled exploitation of nature.The evidence discovered indicates that the only way to preserve the unique nature of Pryorillia is to create a national park in the basin of the Oril with implementation of full nature protection measures and defining the management responsible for preserving the natural and historicalcultural heritage across its entire territory.In total, during 2015, more than 30 expedition field routes of different levels of complexity were realized, more than 50 key areas in all types of landscapes and habitats on the territory of the projected park were examined, more than 20 thousand scientific and artistic photos were taken, around 100 geobotanical samples and descriptions of landscape types were made, dozens of entomological and ichthyological samples were taken, a great amount of cartographic data and satellite photos was analyzed, more than 250 literature sources were analyzed, etc.Only the most important material, accumulated during this year`s project was used to write 6 volumes of scientific justification, which will form the basis for the further creation of the park, organization there of monitoring researches on biodiversity, systematic nature protection, organization of tourism, etc.The complexity of research is clearly illustrated by the composition of the group -it included botanists and geobotanists, ecologists, a hydrologist, an entomologist, an ichthyologist, an ornithologist, a mycologist, a climatologist and geologists.The involvement of geologists in such projects, and correspondingly in the significance of the studies` results, is an exception rather than common practice.For many years, not only in Ukraine, but also in the majority of European countries, the designation of valuable objects of the natural environment was made on the basis of wildlife, geological heritage was either not considered or was ignored (Vol.Manyuk, 2014).The situation slightly changed after establishment of the European Association for the Conservation of the Geological Heritage, but interest in geological natural relics and in geology on the whole has arisen only after the first geological parks were opened (Vad.Manyuk, Vol. Manyuk, 2010, 2011, 2012).
The first geological reserves are those in Reserve Geologique de Haute-Provence Provance (France), Natural History Museum of Lesvos Petrified Forest (Greece), Geopark Gerolstein/Vulkaneifel (Germany) and Maestrazgo Cultural Park (Spain) (Zouros, 2004).These parks, like any similar park, have geological content as their determinant, and all existing 69 geoparks in 23 countries of the world became significant centers of geotourism development (UNESCO Geoparks, 1999;Understanding and Conserving, 2016).
The presence of outcrops on the territory of the planned Orilskyi National Park, or number of outcrops of different ages in this territorial unit is in itself not enough for creating a geopark, but the geological structure of the territory is quite complicated and diverse.The history of its geological development covers the time from the Precambrian age (3.2 billion years) to modern Quaternary deposits.Presentation of general material.In structurally tectonic aspect, the territory of the planned National Park is situated in the area of conjunction between the Middle-Dniprean megablock of the Ukrainian Shield and the Dniprovsko-Donetska depression.The structure of Dniprovsko-Donetska depression includes the south slope and pre-slope parts of the central zone, which are separated by the Myhailivskyi deep fault (Fig. 3).The entire area is characterized by a double-structural level tectonic structure.The lower level is composed of metamorphic, ultra metamorphic and intrusive formations of crystalline basement.The upper structural level, which belongs to the platform mantle, is full of Paleozoic-Cenozoic deposits.The Precambrian structural level is a basement of metamorphic and intrusive formations of the Paleoarchean, Mesoarchean and Paleoproterozoic epochs.The formations of this level in the south-west part of the park outcrop to the pre-Quaternary surface with a depth of bedding of only 20 m, and in the east part of the territory, in the area of Yablunivka village, they lie at depths of more than 9.8 km.
The level consists of two structural stages.The lower stage belongs to the pre-greenstone phase, which consists of metamorphous formations of the Aul series with granitoids of the Dnipropetrovskyi complex.The upper structural level belongs to the greenstone Mesoarchean epoch of Middle Prydniprovie and is represented by metamorphous formations of the Konkska series with intrusive rocks of the Verhivtsevskyi and Surskyi complex, and also Bilozerska suite with manifestations of the intrusive Varvarivskyi complex.Granitoids of lower stage consist of the Tsarychanskyi anticlinorium.The formation of the upper stage is connected with filling and accumulating volcanic and volcanogenic-sedimentary rocks of greenstone rift structures.The upper structural level -platform mantle, with structural incongruity lies in the lower (Precambrian) structural level.It includes three stages.The structure of the level is characterized by three regional surfaces of structural nonconformity -the first relates to structural nonconformity between Precambrian rocks and Dnipro-Donetsk depression (DDD) deposits, the second -between Paleozoic and Mesozoic deposits of DDD, the third -between Cenozoic-Quaternary cover and formations embedded below.The first stage was formed due to the Hercynian phase of orogeny and is characterized by involvement of Pa-leozoic deposits.The second stage is related to Alpine tectonic activization and is represented by Mesozoic deposits.The third stage is characterized by involvement of Cenozoic-Quaternary deposits.The structure of the upper stage includes two parts with areas of different sizes-area of South onboard and pre-board parts of the Central zone, which are separated by the Myhailivskyi deep fault.The South board of DDD includes rocks of low and middle sections of a hard coal system, which are characterized by terrigenous section and accumulation of a rhythmically structured layer with typical alternation of sandstones, argillites, siltstones with limestons and beds of hard coal.Tectonic dislocation is higher compared to the Mesozoic structural stage -here a number of faults are registered.This causes increase in thickness of the stage near the eastern border (Fig. 4).
The area of pre-board part of the Central graben covers the territory north of the Myhailivskyi deep fault.The geological section of the Paleozoic structural stage, unlike the board of DDD, is characterized by a fuller thickness, beginning with Upper Devonian rocks to Upper Carboniferous rocks.Apart from deep faults, the area here includes tectonic structures, which are absent within the onboard territory of DDD.First of all, this relates to numerous dome structures, common for all the area of the Central graben.The best known are Zachepylivskyi, Myhailivskyi, Hupatskyi, Riaskivskyi, Yurivskyi, Kremenivskyi, Vynohradivskyi and others (Fig. 3).The main part of the dome structure is brachy-axis in form with dip angle between the limbs from 15 tо 45°.Another specific tectonic form connected with the Lower stage is saline diapir.In the area covered by this research the Riaskivskyi and Pereshchepynskyi domes were identified.The extent of the fault tectonic is different for each structural level and each stage.The most dislocated fault structures are the lower level, crystalline basement, and Paleozoic deposits of second level.The Mesozoic and Cenozoic stages, which have slight shifts along the Fig. 4 Geological section of Mesozoic sediments Orilskyi National Park activated old deep faults or which have neotectonic deep faults, were practically not affected by disjunctive tectonic.The basement`s largest deep-seated fault is the Dniprodzerjyns`ky deep-seated fault, which expands more than 300 km from the edge of the park`s southern border.It is well distinguished in geophysical fields and is prominent in decrypted satellite photographs.The fault tectonic of Paleozoic stage is characterized by a series of faults, developed within the Kalmius-Nesvitaievska structural-facial zone (SFZ), which are secondary according to the extent of effect upon the geological structure.These are the Mohylivskyi, Hrabivskyi, Chaplynskyi and Ulianivskyi faults.The Myhailivskyi deep fault is determinant in tectonics of Paleozoic rocks.Rapid downward shifting of Paleozoic deposits and Mesozoic rocks took place along the fault towards the axis of DDD.The Mesozoic (middle) structural stage is practically the same territorially as the Paleozoic stage and is characterized by the absence of faults.Tectonic activity of Alpine cycle caused formations of antiforms in the area of the pre-board part of the Central graben.These structures include, first of all, the Levnentsivsko-Nehvoroshchanska antiform, which is characterized by a swell-like structure and flat-lying angle of dip between the limbs, which equals 5-15°.Its development was caused by upward shifting.An important role in fault (disjunctive) tectonic manifestations was played by the Mahdalynivskyi, Holubivskyi, Karabynivskyi, Bulahivskyi and other faults(Fig.3).Morphological studies have shown that during the Neogene-Quaternary period low-amplitude neotectonic movements occurred.This is witnessed by deformations of lengthwise and diametrical profiles of rivers and their tributaries, changes in intensity of erosion process within certain tectonic blocks, etc.
The oldest stratigraphic Precambrian deposits of the basement are represented by significantly metamorphically altered formations of the Bazavlutska rock mass of Aulska seria of Paleoarchean era (AR-1 bz).In some places the rock mass appears as buttes of different shape and size around ultrametamorphic granitoids of the Dnipropetrovskyi complex (Fig. 2).A section of Bazavlutska rock mass is an alternation of biotite-amphibolic gneisses, amphibolites and pyroxene-amfibole-plagioclase crystalline schists with general thickness of more than 3 km.The Bazavlutska rock formation is overlapped by highly structural and stratigraphically dislocated Konkska seria, which forms greenstone structures.Granitoids of ultrametamorphic Dnipropetrovskyi complex, which are the most significant in the crystalline basement`s structure, are represented by two associations: plagiomigmatite-plagiogranite and diorite-plagiogranite association.Autochthonous granitoids are divided in two phases: the first includes plagiomigmatites of biotitic, more rarely of amphibole-biotitic compound, and later -the second phase, which includes more homogenic plagiogranites of different compound.The diorite-tonalite-plagiogranite association ends the process of forming the complex.
Over a period of time (around 2 billion years) the Precambrian rocks of the basement were affected by intense weathering.A thick weathering crust was formed.It has a surface type of distribution (Fig. 5).The thickness of the weathering crust is controlled by the ancient pattern of the basement and by tectonic dislocations.In the valleys of rivers with shore lines at the level of crystalline rocks, and also on their slopes and in separate ravines, the weathering crust is often partly waterworn, and in some places is completely absent.There are two types of the crust: areal and linear (crack).The last is very limited in distribution and relates to weakened zones of separate faulting.In the area of DDD, the crust distribution has a mostly insular character with a thickness to 10 m (seldom to 20-30 m).The weathering crust is characterized by a zonal structure, which was caused by the extent of changes of primary minerals and their replacement by supergene products.According to this feature, in the profile of the crust, four zones were defined: 1. Zone of disintegration and lixiviation; 2. Zone of decomposing and transitional products of weathering; 3. Zone of supergene (final, stable) products of weathering; 4. Zone of lateritization.The first and the second (kaolinite-montmorillonite-hydromicaceous, kaolinite-hydromicaceous, montmorillonite-hydromicaceous-kaolinite, hypochlorite-montmorillonite, hydromicaceous-montmorillonite, hydromicaceouskaolinite) zones have the widest development.The third, quartz-kaolinite, kaolinite zone is developed in the south part of the region.
The Phanerozoic sedimentary sheath, which is situated higher, is represented by Paleozoic, Mesozoic and Cenozoic erathems.A section of Paleozoic erathem within the territory under consideration is represented by Devonian and Carboniferous systems, which belong to the Kalmius-Nesvitaievska structural-facial zone (Fig. 6).

Fig. 6 Stratigraphic scheme of Paleozoic sediments
Devonian deposits lie deep (from 1460 to 2644 m) within the south SFZ of the central polyzone of the DDD, where their southern border of distribution coincides with the Myhailivskyi deep fault.They are deposited with stratigraphic and structural dislocation on Precambrian formations.Devonian rocks are represented by Frasnian and Famennian stages, and appear as a terrigenous-carbonate Suprasalt section with layers of rock-salt.The thickness of the Devonian layer fluctuates between 650 to 1300 m and increases in the north-west.Its lithologic composition is of breccia, anhydrite, clay shale, lime stone, sandstone and rock-salt.Ichnianska rock formation, which belongs to Livenskyi horizon of Frasnian stage, with structural and stratigraphic dislocation is embedded on crystalline Precambrian formations, and is overlain by Kalaidyntsevska rock formation of the Famennian stage.It is represented by large crystalline rock-salt of dark-grey and black colour.Also, apart from salt, the section has interlayers of grey sandstones of arkosic compound with nonuniform-grain psammitic structure.The Kalaidyntsevska rock formation belongs to Yeletskyi horizon of Fammenian stage, embedded with stratigraphic dislocation on Ichn`avs`ka rock formation and is overlain by terrigenous Horobtsivska rock formation.It is characterized by a tophaceous section varying in thickness from 255m to 968m.In lithologic aspect, the rock formation is represented by arkosic sandstones, gravelites, siltstones, with rare argillites, and rare interlayers of conglomerates.Horobtsivska rock formation of Famennian stage are embedded with a perturbation on the Kalaidyntsevska rock formation.Horobzivs`ka svita is characterized by motley colour and compound: gravellite ferruginized by brownish arkosic sandstones, siltstones and argillites.
The Permian system within the Asselian stage of lower section is embedded on hard coal terrigenous formations of the central zone of DDD.Lithologically it is composed of rock-salt, anhydrite, dolomites with rare limestones and siltstones of the Slavianska, Mykytivska and Kartamyska rock formations with thickness of 1.6 km.The only place, where salt diapir expels rock-salt and other rocks of the Permian system practically to the surface (under the cover of anthropogenic rocks), is the upper ravine Zhukova near Pereshchepine town.
Above, not corresponding with stratigraphic perturbation, a dislocated complex of Mesozoic erathem is embedded; it is represented by Triassic and Jurassic systems (Fig. 7).The Triassic system is characterized by a motley sandy-clay section with monoclinal deposits at a slant of 1° to 3° on a trimming surface of hard coal deposits.Sediments of Triassic system are divided into deposits of Lower and Upper sections.According to palaeontological data (discovery of Charophyta) rocks of upper bench belongs to V zone -Stellatochara dnіeprovica.Apart from Charophyta, Ostracoda parts have been found.The thickness of the upper bench is up to 200 m.
The Jurassic system within the South-east and Central SFZ of DDD is represented by lower (undi-Fig.7 Stratigraphic scheme of Mesozoic sediments vided), middle and all stages of upper section, which is divided into rock formations.The Middle section includes Bajocian, Bathonian and Callovian stages, which correspond to Orelska (J 2 or), Pidluzhna (J 2 pd) and Kamenska (J 2 km) rock formations, to the lower subformation of the Solohivska rock formation and Ichnianska rock formation, which belong to the lower part of the Solohskyi horizon and Callovian stage correspondingly.Due to their insignificant thickness, they outcrop as a quite narrow stripe on the surface of Precallovian formations.The thickness of the Jurassic deposits is up to 690 m (in the area of Yablunivka village).The Jurassic section mostly consists of quartzitic and quarts-glauconite sands and sandstones, clay with interlayers of siderites with secondary interlayers of carbonaceous clays.The stratigraphic division of the Jurassic deposits into stages is well attested by numerous discoveries of the fossils Bivalvia, Ammonoidea, Belemnitida.
Cretaceous deposits have a limited distribution in the area of the south west SFZ of DDD, where they fill the core parts of brachy-synclinal folds.Also, in the north-east corner, deposits enclose the Mesozoic section and are monoclinally embedded with flattened dip angles towards the central part of the DDD.The Cretaceous system consists of lower and upper sections.The general thickness of the Cretaceous sediments fluctuates between 0 to 181.5 m.The lower section includes Aptian and Albian stages, which are represented by the Leliakivska and Buromska rock formations correspondingly.The Leliakivska rock formation consists of lacustrine-continental sediments -quartzitic fine-grained and coarse-grained sands and sandstones of grey and dark-grey, sometimes greenish-grey colour.There are scattered interlayers of grey and dark-grey clays.It is embedded in the stratigraphic dislocation on the Veneslavivska rock formation of the Upper Jurassic epoch, and is overlapped by Buromska rock formation with stratigraphic dislocation.The thickness of the Leliaevska rock formation deposits on average is 38-39.0m and fluctuates between 16 and 47 m.The Continental Aptian stage includes embedded stratigraphically dislocated Buromska rock formation, which belongs to the upper part of the Albian stage of the Lower Cretaceous section.The section of rock formation is composed of quartzitic and glauconite-quartzitic grey and greenish-grey sands of fine-grained structure with interlayers of siliceous-quartzitic sandstones and dense clays of grey and greenish-grey colour.Often phosphorite concretions are found.The age of the rock formation and its stratigraphic location is determined through the discovery of Gumbelitria cenomana (K e l l e r) foraminifera's.The thickness of the rock formation fluctuates between 41 m and 45.5 m.
Cenozoic erathem is represented by Paleogene, Neogene and Quaternary systems, which are embedded with a fairly large perturbation on rocks of crystalline basement or on deposits of hard coal, Triassic, Jurassic and Cretaceous systems within three SFZ: Prydniprovska, South-west and Central (Fig. 8).
The Paleogene system includes Eocene and Oligocene sections.Eocene is represented by Buchats`ka seria, Kyivs`ka and Obuhivs`ka suite.The Buchatska suite is distributed in the territory of DDD and Ukrainian Shield within Prydniprovska, south-west and central SFZ.Prydniprovska SFZ is characterized by continental compound of Buchatska seria, and south-west and central SFZ include marine types of Buchatska seria in Kostianetska rock formation.Continental deposits of Buchatska seria are distributed in buried paleodepressions of crystalline basement and are represented by subaqueous continental facies: alluvial, lacustrine, alluviallacustrine, swampy parts of the Prydniprovska SFZ paleoriver deltas.
In the south-west and central SFZ, the Buchatska seria is represented by the grey, brown-grey to grey glauconite-quartzitic carbonaceous sands of the Kostianetska rock formation.Marine shallow-water terrigenous sediments of the Kostianetska rock formation are embedded horizontally with angular displacement and stratigraphic dislocation on Paleozoic, Mesozoic rocks of crystalline basement.The thickness of the marine deposits is quite stable and fluctuates between 40 m and 60 m towards the axial part of the paleodepression.The age of the rock formation was determined through the identification of faraminiferan: Spiplectammina ex gr.variata V a s s і l., Bulimina mitgarriana B a l a c h m. and others.
The Kyivska suite is distributed throughout the projected park, apart from the area contiguous to the Dnipro, where the crystalline basement is lifted high.It is embedded transgressively without notable perturbation on the Buchatska seria and is characterized by a fairly uniform lithological compound, where light-green-grey marl with glauconite and secondary interlayers of green-grey limestone clays dominate (Fig. 9).The thickness of the Kyivska rock formation deposits is 20-25 m.The age of the rock formation is determined by the remains of fossil Mollusca, Foraminifera and nanoplankton.The bottom of the rock formation includes small concretions of phosphorites.   of the bench are characterized by horizontal microbedding, which is emphasized by thin (0.5-1.0 cm) interlayers of greenish-grey clay, which interchange with sand after 10-12 cm.The age was determined through spore-pollen analysis.
The Neogene system is represented by Miocene and Pliocene sections (Fig. 10).The Miocene section begins with the Novopetrivska rock formation, which according to lithological features and according to fossil fauna from the studied territory is represented by middle and upper subformations.The upper subformation includes mostly quarzitic yellow grey sands of average-fine-grained structures, which are clayey and micro-bedded with lenses of gravel.Sometimes, the upper part of the section is represented by ferruginized sand with interlayers of sandstones on ferriferous-clayey cement (Fig. 11).
Also, the overlying beds of sand often include layers of grey finely dispersed clays with typical surfaces of colloidal varnish.The section of these clays can be observed in the outcrop on the slope of the Bohatenka river.The middle subformation is characterized by dominant distribution of quartzitic, light-grey, fine-grained, well sorted sands, with different types of cross-bedding, with lenses of coarse sands and thin interlayers of grey, often kaolinious clays (Fig. 12).The rock formation has a ubiquitous distribution, except in the valley of the Oril river, where it was completely washed out and replaced by alluvial deposits.
The thickness of the deposits is 10-18 m.Upper Miocene is represented by a layer of sands (N 1 p), which correlates with Middle Sarmatian deposits of adjoining areas, which are dated faunistically.The sandy layer belongs to a coastal-marine facies, is transgressively embedded with erosion on sands of middle subformations of the Novopetrivska rock formation.The absolute top level of its surface varies from +99 m to +123 m.The thickness of the sand layer fluctuates from 0 to 18 m.The section of the layer consists of quartzitic sands of grey-greenish, yellowlight-grey to motley (crimson, cherry-red) colour of fine-grained, sometimes middle-grained sands in the lows of the section.The sands have low-thickness (to 20 cm) interlayers and lenses of quartzitic grey or white sandstones on clayey cement.The upper A layer of Pliocene red-brown clays (N 2 čb) is characterized by a very small area of distributiononly on areas of watershed divides in the north-east and south-west parts of the territory.It is represented by clays and sandy clays.The layer of red-brown clays is clearly distinguished in section by its typical brown-red or red-brown colour.The layer of redbrown clays is intensely eroded; its surface is inclined to the west or north-west with an absolute level from +119 m to +99.2 m, and the clays of Prydniprovska SFZ (between points +137-119 m) have the highest hypsometric level.The thickness of the red-brown clay layer is 2.5-6.0 m.
The Quaternary system is represented by subaerial and subaquetious deposits of rocks of different genetic types, which are typical for glacial and periglacial zones (Fig. 13).
The section of system involves Eopleistocene, Pleistocene and Holocene sections.Its lower limit is 1.82 ml years old.The Eopleistocene section includes Kryzhanivskyi and Shyrokynskyi fossil redbrown soils, which interbed with Berezanskyi and Illichivskyi climatoliths of lacustrine origin.Lithologically, these are clays and heavy loams with carbonaceous concretions and dendrites of manganese oxides.The Pleistocene section is characterized by interbedding of yellow-ochre loess and loess loams, formed during cold glacial periods with fossil soils of warm interglacial epochs.According to regionalization of the Quaternary deposits, the south-west part of the projected park is in the subzone of maximum glaciation of the Dniprovska glacier zones, and north-Fig.13 Map of Quaternary sediments east and east -in the north loess subzone of out-glacier (periglacial) zones (Fig. 14).
In the out-glacier zone, Pleistocene deposits are represented by lower, middle and upper sections.Upward, these are Pryazovskyi, Martonovskyi, Sulskyi, Lubenskyi and Tilihulskyi climatiliths of lower section of Neopleistocene rocks; Zavadivskyi, Dniprovskyi, Kodatskyi and Tiasmynskyi horizons of middle sections, and also Prylutskyi, Udaiiskyi, Vitachevskyi, Buzkyi, Dofinivskyi and Prychornomorskyi Kryomers and Thermomers of upper sec-tion.Loess and loess loam are of light-brown colour and yellow-ochre colour, light, porous, highly limestone.Fossil soils differ by their much darker colour -brown-grey, red, dark-grey, non-uniform, often include carbonaceous and gypsum concretions.The thickness of certain climatoliths is from 0.5 m to 5 m, the general thickness of the Quaternary deposits is up to 27 m.They are distributed mostly in watershed dividing areas and are partly present on upper levels of the Oril terraces.In the glacier zone, the section is represented only by middle and upper part, the depos-Fig.14 Stratigraphic scheme of Quaternary sediments its of the lower part were destroyed by formation of exarational processes of glacier and by glacio-fluvial flows.During the formation of subaerial deposits of watershed divides in the Oril valley and its tributaries, subaquetious formations of the first (Desnianska ) and the second (Vilshanska ) and the third (Trubizka) above flood-plain terraces and floodplains.
These are alluvial sands, clayey-sandy deposits of oxbow lakes, loams and sand terraces, proluvial-deluvial deposits of ravines, steep banks and small erosional forms, lacustrine-swampy deposits.The Dniprovskyi climatolith consists of glacier formations, which are embedded horizontally on Quaternary deposits and are widely distributed in the glacier zone.The climatolith includes a composed complex of genetic types, which lay in the basis of its more detailed division.The Dniprovskyi climatolith is divided into lower, -middle, and upper Dniprovskyi stades.The lower stade is composed of fluvio-glacial sediments -fP II dn 1 (Fig. 15).The rocks of the lower stade are easily identified through their typical grey, dirty-grey colour, which is caused by debris of organic substance and rounded coarse-grained material.In secondary deposits, well maintained seashells of freshwater Mollusca, and also spicules of spunges, Foraminifera and Radiolaria were found.
The middle stade is represented by lacustrine-glacier moraine (ground) and fluvio-glacier deposits, which correspond to middle and upper benches of "Shevchenkivska suites" -lg P II dn 2 .In section, they are distinguished by the clearly manifested character of lower and upper contacts -they are embedded on fluvio-glacier sands, and are overlapped by ablation moraine.The section of the lower part of the Serednodniprovskyi climatolith section is completed by lacustrine-glacier deposits, which overlap ground moraine.The upper stade is represented by boundary moraine -gkP II dn 3 .Its outcrops are represented best on Kalytva hill.Fluvio-glacial deposits are found in flow buttes and spread under boundary glacier formations of Kalytva hill.They are represented by quartz-itic fine, -medium grained light-grey sands with large content of debris of granite, limestones, sandstones, quartzites.The substance compound is represented by quartz, fieldspars, and glauconite in small amounts.Fluvio-glacial deposits of Kalytva hill are dislocative, cross-bedding, diverse according to granulometric compound, sometimes include carbonaceous remains of plants, fragments of petrified wood.An important feature of the glacier dislocations of Kalytva hill as end moraine formation is the erratic mass of Paleogene rocks among Quaternary deposits.They are identified through drilling, and also they are outcropped in the north-east part of the Kalytva hill.
Kalytva hill consists of dislocative fluvio-glacial, lacustrine-glacial sediments with a significant, according to the size (to giant), erratic mass of Paleogene rocks.These layers of rocks frequently cross-bedded one another in scale form, causing folds.The only fluvio-glacial deposits which remained undislocated are those which are embedded directly under the ablation moraine.On a limited scale, on higher areas of watershed divides, under the Dniprovskyi horizon, Kodatskyi fossil soil (Р ІІ kd) and Tiasmynskyi forest-type loam (P II ts) are embedded.Their general thickness is 5-7 m.
Deposits of upper section of Neopleistocene rocks are common in the watershed divide of the Oril's Left Bank.They consist of the Trubezka Vilshanska and Desnianska levels.They are a rhythmical interchange of loess horizons (Prychornomorskyi, Buzkyi and Udaiskyi) and fossil soils (Dofinivskyi, Vitachevskyi and Prylutskyi) with general thickness 9-15 m.Fragments of Upper Quaternary loam section can be seen in small quarries in Zinkivshina village, and in Novopidkriazh.Subaquetious deposits of upper section consist of the lower part of Desnianska (а 1 Р ІІІ ds), Vilshanska (а 2 Р ІІІ vl) and Trubizka terrace (а 3 Р ІІІ tb), distributed along the left slope of the Oril river.Alluvium of the Trubetska terrace extends as a large stripe along the Oril valley and the edge of the watershed divide.In the base of alluvial thickness, gravelites Fig. 15 Geological section of Quaternary sediments are embedded.They lie as conglomerate of 0.4-0.5 m thickness.Debris material is represented by granites, gneiss, quartz, flint stones, carbonates, and are 0.5-1.0cm in size, sometimes to 2.5-4.5 cm.The general thickness of the terrace is 10-15 m.Alluvium of the Vilshanska terrace is distributed on the left bank of the Oril river and is adjacent to Trubetska terrace.It is separated from Desnianska terrace by a ledge, which is controlled by structure contour +65-70 m.The basis of the section (mouth facies) includes deposits of gravelites of 0.4-0.5 m thickness, which are composed of debris of carbonaceous and crystalline rocks.Its lower part (thickness -4-6 m) is represented by quartzitic medium-grained sands of grey, lightgrey colour with a yellow tone, with small addition of coarse fraction.The general thickness of the terrace deposits is 9-11.5 m.The upper part of the section is composed of dark-grey aleurites and sands, which are very clayey, humic, often carbonaceous.Its thickness is not significant -0.7-1.7 m, but in some cases it reaches 4-5 m.The section of terrace is completed by sandy clays of grey colour with interlayers of mule, and carbonaceous clays with remains of carbonized vegetation.The thickness of clays fluctuates between 1.0 to 1.5 m.The general thickness of the Desnianska terrace is 10-12 m.
The Holocene series is represented by a wide range of genetic types: eluvial, alluvial, lacustrine, Aeolian, proluvial, swampy and alluvial-delluvial type.On watershed divides, Holocene eluvial rocks are represented by common oligohumic chernozem, and in the valley of the Orel river, is represented by a wide range of different soils: alluvial meadow solonetic, meadow-swampy, sabulous and clayey-sandy chernozems, turfy sandy soils which are developed on hillocks, and by meadow chernozems on 1-2 terraces, etc. Lacustrine and lacustrine-swampy (lbH) facies of artificial water reservoirs and the floodplains of the major rivers and their tributaries are clayey-sludge formations of dark-grey and black colour, often with additions of sandy fine-grained fractions, usually with clearly manifested horizontal bedding caused by interchange of viscous plastic, sandy, more friable clays and sand itself.The thickness of the lacustrine deposits is from 0.5-1.5 m to 3-5 m.The latter are characterized by argillaceous-sabulous-loamy compound, nonuniformity, poor sorting or no sorting, debris texture, additions of carbonaceous material and hillside diluvium.The alluvium deposits (аН) have small areas of distribution and are timed to low floodplains of the Oril and its tributaries.Alluvial facies includes channel and floodplain subfacies.The latter are widely distributed within expansions of floodplains up to 500-700 m.The alluvial layer is composed of quartzitic sands of up to 14 m thickness.The lower part of the section includes deposits of coarse sands with pebbles and gravel of quartzitic compound.The upper part of the section is composed of humic finegrained sands, aleurites.Aeolian sands (vH) have a limited distribution in the lower flow of the Oril valey.The area of distribution of the Trubizka and Vilshanska terraces also includes so-called hillocks, which are located, at the same time, at all levels of terraces as sandy hills or group of hills, which are united in ridges.They are represented by fine-grained sands, with additions of medium-grade, slightly clayey quartzitic sands.They are friable, well sorted, light-grey with yellowish tone.As the saturation of humus increases upward, they gradually change to brown types.The thickness of the light part of the section is 1.0-2.5 m, thickness of the brown part is 3.0-4.8m.In general, the thickness of the Aeolian sands fluctuates between 3.0 to 7.5 m.Alluvial-deluvial deposits (adH) fill the bottoms of small erosional forms (small rivers, ravines, steep banks, lowlands, washouts) with temporary gullies.The latter are characterized by clayey-sabulous-loamy compound, non-uniformity, poor sorting or no sorting, debris texture, additions of carbonaceous material and slope deluvial deposits.The deposits are laminated due to interchange of interlayers of sand clay, chernozem, loam and other.The alluvial-deluvial deposits are low capable, their thickness is 1.5-7 m.Occasionaly, among them, ferruginization and hydroxids of manganese are found.Technogenic formations (tH) are composed of rocks of different lithological compound, genesis and age.They had been formed due to agricultural activities.According to types, they are bulky, filling, inwashed, deposits of mixing (agrotechnical), deposits of buildings and structures, deposits of horizon, technogenically altered.Within the park, bulk type is considered to include mostly terrigenous deposits of transport, protectoral and constructional bulks like sand, gravel, pebble, gruss which appear as swells, dams, gibbous-steeply-sloping forms of landscape.Filling types are facies of linear geological bodies, which are formed after filling in steep banks, trenches, ditches; punctual types which appear after filling in wells, sumps after drilling, pits and surface types -after filling in lake basins, swamps after land reclamation.Inwash deposits, formed due to hydraulic monitors, are located on the Dnipro`s shore area and are represented by dams and constructional grounds.The terraces of the Oril and watersheds are rich in agrotechnical deposits, which were caused by shifts of agricultural mechanism of the soil layer, addition of organic and mineral fertilizers.Technogenically-caused deposits include deposits of different genesis, which were formed due to various processes .These are Dnipro-Donbas canal, and various extensive irrigation systems and the new channel of the Oril river.These deposits have a fluctuating thickness (from 1 to 15-20 m), chaotic compound and various forms.
Geomorphological regionalization is considered in accordance with the general scheme of regionalization (Fig. 16).According to tectonic regionalization, the greater part of the territory is situated within DDD and is represented by a part of the province of the Prydniprovska depression.The province includes the Prydniprovska alluvial depression (А-I-1), which is a component of the area of the Serednoprydniprovska alluvial depression on a washed-out Paleogenous-Neogene base (А-І).The valley of the Oril river east from Nehvorosha village is situated within the Orilska alluvial plain (А-II-2), which belongs to the Poltavsko-Karlivska insignificantly broken plain.Upper parts of the left slope of the Oril river valley with tributaries and ravines and adjoining parts of the watershed divide belong to the Mahdalynivskyi insignificantly broken plain (А-II 3).In the area of the Serednoprydniprovskyi alluvial depression, also the following areas are substracted: Tsarychanska alluvial flat plain and fluvio-glacial and moraine deposits (А-І-ІІ-б) of the Yahotynska insignificantly broken plain (Fig. 16).
Morphostructures of lower orders, which are inherited by local structures of post-Devonian deposition -Katerynivska and Leventsivska, are poorly manifested in the modern landscape, but are defined by morphometric studies.
Morphometric studies indicate that sign (degree of elevation or depression) and amplitude of the recent shifts define the direction of fluvial processes upon the erosion or accumulation or whether depth erosion or lateral erosion take place in the basin of the Oril and its tributaries.Correspondingly, the Orilska erosional-accumulating plain is characterized by significantly dominating processes of accumulation, typical abnormal extensions of the valley of the Oril and its biggest tributaries, intense meandering of water courses, lowland areas, terracing of the valley, formation of numerous oxbow lakes, swamping, etc.Studies have also shown that the valley of the Oril river in its upper flow (to Orelka village) inherits the Orelsko-Udaiskyi deep fault, and in the middle flow it flows parallel to the Myhailivskyi deep fault.
In the modern landscape, the following types of landscape are: structural-denudation, erosion-accumulating, Aeolian and gravitational.Structural denudation of the landscape is represented by watershed divide plateau, areas of which within the territory of the park conjunct with the left slope of the Oril valley .Its structure includes Paleogene, Neogene and Quaternary deposits.Denudation of the landscape develops on the slopes of the plateau.There is no straight boundary between the plateau and its slopes, there is a gradual lowering of the plateau`s surface towards the river and ravines.The surface of the plateau lowers in a north-westerly direction from +115 m to +76 m (the surface of second terrace).
The main geomorphological form is the valley of the Oril river.Its modern appearance was formed by the activity of the Dniprovskyi glacier and erosion-accumulating processes during the post-glacier period.The valley of the river, which is characterized by a gradual stream gradient, wide not deep profile, is formed by erosion processes and has adjusted itself to fault tectonic zones.Morphometric studies indicate that sign and amplitude of the most recent shifts define the direction of fluvial processes upon the erosion or accumulation or upon whether depth erosion or lateral erosion take place in the basin of the Oril and its tributaries.Correspondingly, the Poltavsko-Orilska erosion-accumulating plain has significantly dominated processes of accumulation, typical abnormal extensions of the Oril valley and its main tributaries, intense meandering of water courses, lowland areas, formation of numerous oxbow lakes, swamping, etc.The long term tendency of the Ukrainian shield to lift with lowering of the Dniprovskyi graben at the same time is caused by the shifting of the Oril valley during the late Pliocene-Quaternary period from south to north and towards east, and the domination of accumulation processes upon the erosion processes is manifested.The surface landscape of the plateau and left slope of valley of the Oril river is intensely divided by lateral ravines, including ravines Vasetskoho, Vodiana, Dubova, Kilchenka, Bohatenka, Bezverha and by small erosion forms.
The largest right bank tributaries of the Oril are the rivers Nehvoroshanka, Lypianka, Orchyk, Berestova, Bohata and the Zhuchyha, Komisarova, Mozharka ravines, whose mouths extend into the north edge of the park.The largest among them are the Lypianka, Orchyk, Berestova.They are characterized by a longitudinal profile of equilibrium, very gradual stream gradient, significantly meandering channel with areas of swamping and loops in pre-mouth areas.
The Oril is characterized by a gradual stream gradient, intense meandering at its mouth with formation of numerous bends, oxbowlakes, channels, eriks and areas of swamping.The length of the Oril from Yablunivka village in the east to Yelizavetika in the south-west is 261 km and is characterized by a change of stream gradient from +94m to +55m.Therefore, the average drop in elevation of the stream is 0.15 m/km.Meanders in the valley of the Oril and other lower parts of the tributaries, according to the shape, are as follows: segmented, omega-like, harp, sinusoidal, inverted, loop, chest-like and composed.According to origin, wandering, mostly fossil, ruptured, separated meanders, etc dominate.The width of the meander belt in some places is up to 3.8 km.The dynamics (stages) of meander development can be observed: i.e. formation of meanders, their shifts down the current, partial and full breakthrough, constriction of meanders and their transformation into  An important element of the Oril valley's structure is the terraces, which are seen along the left shore and are characterzed by ledges, brows and inner margins, which are clearly substracted.The Desnianska terrace (a 1 P III ds) is made of wide swamped depressions.The structure of the second terrace is composed of two layers.The lower layer is of alluvial type and is composed of sands and gravel.The upper layer is subaerial and is composed, mostly, of products of Aeolian origin -sand clays and clays.The terrace`s width in different parts of the valley is 0.5-1 km to 4.5 km.In the lower current of the river, the width of terrace is up to 9-12 km.The Vilshanska terrace (a 2 P 111 vl) is located on the left bank of the river and is above the level of the Desnianska terrace by 4-7 m.A specific feature of the Vilshanska terrace is the intense development of areas of swamping.The surface of the terrace is relatively flat with relicts of oxbow lakes, which tend to be overgrown, former channels and branches, with alluvial fans.The surface of the Vilshanska terrace is often completed with forms of Aeolian origin: hilly sands, hillocks, small dune-like formations, which include randomly located weathering pits.The contemporary Aeolian ripples on the open space of the wind-blown sands are orientated according to azimuth 270-290°.The thickness of the terrace`s deposits is 13-15 m.The absolute points of the second terrace`s surface are 62-73 m.The third, the Trubizka , above the floodplain terrace (a 3 P 111 tb) spreads as a narrow line between the valley and the watershed divide, having a width of 0.3-0.6 km.Unlike the younger terraces, this terrace has a pre-slope location with no insular areas of streamline.The terrace is 7-11 m higher than the level of the second terrace.A typical section has alluvial deposits of the Trubezka terrace overlapped by two loess horizons, Vitachivskyi and Dofinivskyi fossil soils and modern chernozem.Morphological elements of the third terrace mostly lie under upper Quaternary Aeolian-deluvial and eluvial deposits and were identified only after analysing aerospace images and the results of drilling.The thickness of the terrace`s deposits is 13-25 m.
Aeolian forms are widely spread in the floodplain of the Oril river and are seen within the Vilshanska and Trubezka terraces and are represented by accumulations of sand as hills, so called "hillocks"."Hillocks" are hills of 2.5-4 m height, sometimes 7 m, rarely does a hill`s height reach 10 m.Contemporary Aeolian ripples on the open space of wind blown sands are orientated according to azimuth 270-290°.Gaps between barkhans are local bases of erosion, therefore form drainless forms.
The largest of the left bank tributaries, the Bahatenka river has the status of landscape reserve of local significance.It flows from Pryvilne village at its head to its mouth in Bahate village and is characterized by a dendritic type of division, small length, asymmetric transverse profile, significantly meandering mouth and extensive cascade of artificial water reservoirs.The largest tributaries: ravine Shyroka, Holodna, Lozova-Lehedyna and Kersonivska.The river`s length is 29 km, the area of drainage basin -207 km².
Landscape forms of technogenic type -first of all, the structure of the Dnipro-Donbass canal, structures of residential areas, raised embankments for railroads and highways, quarries for extraction of sands and loams, dams, weirs and artificial water reservoirs, new mouth of the Oril.Conclusions.The geological component of the natural environment is the most important, and often, is its determinant.A complicated interaction of various geological processes defines not only the geodiversity of a territory, but also its biodiversity (Wimbledon & Smith-Meyer, 2012).The formation of a new ecological network and creation of new objects of the nature reserve fund faces the problem of accurate study and further protection of not only the wildlife species, but also protection of so-called inanimate nature.Even if the latter is mostly hidden beneath more recent geological formations, knowledge of its geological development history, peculiarities of stratigraphy, tectonic, volcanism, is especially important for any object of natural heritage -from a natural relic to national park.
The studied territory meets all criteria for the status of national nature park (according to international classification of natural protected territories IUCNcategory II ("national parks").Due to the increase in anthropogenic pressure, further degradation and direct destruction of natural ecosystems in the region, this territory requires not only immediate recognition as an object of the nature reserve fund of Ukraine, but also establishment of an institution with staff and implementation of efficient protection of the territory, control of implementing the nature protection legislation and development of ecologically responsible tourism in the region of Steppe Podniprovia.The Orilskyi National Nature Park is an important element of the ecological network of national value, which is situated at the juncture of the two most important transnational ecological corridors of the Pan-European Eco-network -Dniprovskyi meridian and Ukrainian steppe latitude corridors, and also is the main part of interregional conjunction of territory between left bank Naddniprianskyi foreststeppe and steppe, and between the basins of the Dnipro and Siverskyi Donets.Discoveries made within the territory of the projected park include valuable and unique natural objects (lakes, limans, rills and swamps); more than 40 botanical relics; more than 30 fauna relics; a number of geological and geomorphological relics, including a unique glacialmoraine hill Kalytva).
The creation of the first national park in Dnipropetrovsk oblast will be an event which several generations of Ukrainian intelligentsia have awaited, and in recent years it has also been anticipated by the inhabitants of local villages.It would spur a new stage of development of regional reserves and nature protection, the point where a totally new tourism will develop, which will be responsible for the environment and cultural traditions.Establishment of a protected territory of the highest rank in Pryorillia, which would be organized according to the watershed principle, should contribute to solving a difficult macroecological and highly important social problem of restoring the hydrological regime of one of the most famous and largest river valleys of the Ukrainian steppe zone.In the future, the successful work and development of the park and its territory requires enlargement of its territory by adding areas of the Oril valley within Kharkiv and Poltava oblasts (or providing alternative conservation objects of the highest rank on the territory of these oblasts).

Fig. 5
Fig. 5 Map of weathering crust of crystalline basement rocks (north and south-eastern parts of the National Park "Orilskyi") 1. Michailovskyi depth fault with the direction of the plane of slip line; 2. rock weathering izopach; 3 -area of distribution of end products weathering crust; 4 -area of distribution of intermediate products of weathering crust; 5 -area of distribution of primary products weathering crust; 6 -the area lack of products weathering crust Their general thickness is up to 430 m.The lower Triassic section includes Induan and Olenekian stages.Deposits of the Induan stage are represented by the section of the Dronivska rock formation-Т 1 dr, Olenekian stage -by lower substage of Serebrianska rock formation -Т 1 sr 1 .The Dronivska rock formation of Induan stage is characterized by a motley compound and occupies the lower part of the Triassic section.The Dronivska rock formation includes three benches.Organic remains are represented by charophites, Ostracoda parts, Phyllopoda.The maximum thickness of the upper bench of deposits reaches 62 m, average thickness near the Myhailivskyi deep-fault is 45 m.The Middle Triassic section is represented by Anisian and Ladinian stages, which correspond to upper subformation of the Serebrianska rock formation -Т 2 sr 2 .Nyzhnoserebrianska subformation of Serebrianska rock formation occupies the greater part of the Triassic deposits` distribution area.It belongs to III zone according to charophytes (Porochara triassica (S a i d) G r a m b.) and is embedded, correspondingly, on the upper part of the Dronivska rock formation, is overlapped by the upper subformation of the Serebrianska rock formation.It is represented by red clays with a secondary number of interlayers of marlstones, sands and sandstones, gravelites.The thickness of the gravelite beds fluctuates between 18 m and 47 m.The average thickness of the subformation north of the Myhailivskyi deep-fault is 144 m.
The absolute top level of the deposits is at 40-55 m.Mollusca identified: Spondіlus buchi P h i l i p p i, Nucula bowerbankii S o w., Spondіlus ceptemcostatus S l o d k. and other Foraminifera -Robulus sp., Аnomalina (Pseudovulineria) acuta var.taurica S a m o i l o v a, A. cf.flazenensis N u t l a l l and others.Nanoplankton zones Reticulofenestra umbilica with two subzones: Discoaster bifax and Diascoaster saipanensis prove the Middle Eocene age of the Kyivska rock formation marl.Higher up is embedded the Obuhivska suite.It was formed in coastal-marine conditions, and south-west part of the sheet, which belongs to the Prydniprovska SFZ, includes types of underwater parts of deltas of paleorivers (Fig.9).It is represented by glauconitequartzitic, grey-greenish fine-grained sandstones on clayey cements.The thickness of the rock formation is 20-28 m.The age of the rock formation was defined through identification of Foraminifera, Mollusca typical for Upper Eocene: Nucula, Arca rugifera K o e n., Mosalia margi nata S o k., intense terrestrial vegetation Myrtus, Myrica, Pinus, Costanea, Ficus, and others.Oligocene rocks of the studied territory are represented by Mezhyhirska and Berekska rock formations in marine and coastal-marine facies.They are embedded horizontally with stratigraphic dislocation on the Obuhivska rock formation and with sharp dip unconformity on rocks of crystalline basement.Deposits of Mezhyhirska rock formation are distributed everywhere and are partially washed out in the valley of the Oril and are replaced by alluvial deposits of floodplain and terraces.The thickness of the rock formation fluctuates from 3-4 m to 37 m and is dependent upon the intensity of erosion.The section of rock formation consists of quartz-glauconite siltstones and fine-grained sands.The bottom of the rock formation on the surface of the south-west and central SFZ includes basal horizon, which is coarse-grained sandstones on clayey cement.The Mezhuhirske Sea existed in the conditions of further cooling and is characterized by an impoverished fauna.Most sections have no fossil fauna, but single findings of faraminiferans, spicules of sponges, radiolarians and study of spore-pollen complexes, selected from core sample, indicate that the rocks date from the Oligocene epoch.Deposits of Berekska formation have a limited distribution in small areas of watershed divides, where they were not affected by Quaternary erosion.The lower bench of the rock formation consists of continental facies of lowland plain, fills negative forms of landscape, embedded on the surface of the Mezhuhirska rock formation.The base of the section is friable quartzitic inequigranular sand with additions of gravel.The identified thickness of the alluvial part of the section

Fig. 12
Fig. 12 White quartz sand of Middle novopetrivska suite.Urochysche "Wall" Fig. 11 Section sand of Upper novopetrivska subsuite loops.The landscape here is characterized by numerous branches, channels, rills, floodplain lakes, areas of swamping.The transverse intersection of the valley is asymmetric.The right bank is steep; the left one is flattened and terraced.The long term development of the river valley in the conditions of a high level of erosion and profile of pitching axis equilibrium caused its intense meandering, incredibly complicated pattern of small erosion-accumulating forms.The change of the Oril`s current direction at the right angle towards south-east took place around 250 thousand years ago because of the glacier tongue in the valley of the Dnipro, which obstructed the river`s flow.The new mouth of the Oril goes across the first terrace and partly uses the mouth of the Protovcha river.Contemporary alluvial and alluvial-deluvial deposits fill the mouth of the Oril and the bottoms of ravines and smaller erosion forms -washouts, lowlands, steep banks.

Fig. 16
Fig. 16 Scheme of division into districts the Quaternary deposits (on the basis of structural and geomorphological)