Sudetic Foreland Research Articles

An examination of the glaciomarginal fan of the Odranian glaciation at the Mokrzeszów site, Sudetic Foreland, SW Poland

The article presents the results of research from the Mokrzeszów site in the Sudetic Foreland. Lithopetrographic and sedimentological analyses of sediments from the Middle Polish Glaciations (Early Saalian, Odranian, MIS6) in this area indicate the overrepresentation (90–95%) of large Scandinavian erratics. The deposits, representing a repetitive sequence of Gp-Gms-Sp-Sh/Sr(Dmm) lithofacies, accumulated during at least two episodes of glacial outburst floods and six sedimentary cycles. High-energy flows are estimated for the Gms and Gp facies at about 5 m∙s−1 and low-energy flows indicate 0.8 m∙s−1 for the Sp/Sh/Sr facies, to the lack of flow (Fm). The sedimentary sequences confirm the existence of a fan, which may have originated as a subaqueous steep coarse-grained fan in glacial-flow-lake-outburst floods that formed between the ice sheet front and the morphotectonic edge of the Sudetic Marginal Fault line and within the Roztoka-Mokrzeszów Graben, or as an aerial, piedmont fan on the Sudetic Marginal Fault edge. The sediments show discontinuous deformations – gently sloping faults and fractures from glacioisostatic stresses. The fault activity is probably related to the reactivation of the faults due to ice loading during or after the older Saalian glaciation.

Functionality of early medieval roasters studied using archaeobotany and chromatography: preliminary studies

Roasters are clay, quadrilateral vessels that are found in areas of whole Slavic region. For years, there has been a discussion on their functionality, in which various concepts of their use keep appearing. In this paper we present the results of botanical and gas chromatographic studies carried out on several fragments of roasters that originated in the Sudetes Mountain area and Sudetic Foreland. The analyzed artefacts in total of 26 pieces come from three early medieval sites: Gilów, Jelenia Góra–Grabary and Kamieniec Ząbkowicki. The obtained results allowed to concluding that these were the vessels used for thermal processing of cereal grains in both processes of food processing and food preservation. The results made it possible to move the beginnings of agrarian activity in the Sudetes Mountains by 400 years, earlier than it was thought, which has a key meaning for observation of the economy development in mountainous areas in the early Middle Ages.

Inventory and Assessment of the Geoheritage of the Sudetic Foreland Geopark (South-Western Poland)

Inventory and Assessment of the Geoheritage of the Sudetic Foreland Geopark (South-Western Poland)

Detrital zircon U–Pb age analysis of last glacial loess sources and proglacial sediment dynamics in the Northern European Plain

Loess deposits along the northern fringe of the European loess belt potentially record past changes in dust emission from areas proximal to former ice sheets. Recent chronologies from loess deposits across this region generally agree on greatly enhanced dust deposition rates when the Fennoscandian Ice Sheet reached its maximum extent during the late last glacial. However, uncertainties over the material's source and origin limit understanding of the causes of this enhanced dust activity. In particular, loess in southwestern Poland has been attributed to multiple origins, mainly involving glaciofluvial outwash plains along the Fennoscandian Ice Sheet margin and/or local sources in the mountainous areas of the Sudetes and Western Carpathians. Here we apply detrital zircon U–Pb age analyses for a large number of grains recovered from four loess samples taken from different stratigraphic units exposed at Biały Kościół in southwestern Poland, previously luminescence dated to MIS 4–2, to assess loess provenance as well as its temporal evolution during last glacial Fennoscandian Ice Sheet fluctuations. Furthermore, we analysed the detrital zircon U–Pb age spectra of five samples from potential source sediments to constrain the history of sediment recycling and mixing within the Northern European Plain prior to deflation and loess deposition. The broad range of zircon age components detected in the four loess samples suggests both Fennoscandian and closer Peri-Gondwanan proto-sources while a narrow, dominant Carboniferous age peak is consistent with sourcing from the local Strzelin Hills in the Sudetic foreland. However, the presence of both Fennoscandian and Peri-Gondwanan derived grains in samples from potential source sediments reveals that this mixture of sediment sources is widespread across the Northern European Plain, as a result of long-term glacial and fluvial reworking of cover sediments in the proglacial area throughout the Quaternary. Local rivers draining the Sudetic foreland transported this Fennoscandian-Peri-Gondwanan sediment mixture along with particles denuded from the Strzelin Hills, resulting in a nearby, temporally stable dust source for the Biały Kościół loess during MIS 4–2, while dust emission rates were substantially increased during the last glacial maximum. Given that our model for loess formation at Biały Kościół essentially involves sediment distribution via rivers prior to short distance aeolian transport, we infer that the proportion of northern ice sheet derived particles in European loess deposits is mainly controlled by the drainage pattern of major rivers in relation to Pleistocene ice margins where glaciofluvial sediment is abundant. Based on the presence of Fennoscandian derived zircon grains in European loess deposits, we constrain a southern limit of the influence of northern ice sheet dust sources along the central European highlands that currently divide drainage between the Northern European Plain and the Danube Basins.

Evolution of the Bystrzyca River valley during Middle Pleistocene Interglacial (Sudetic Foreland, south-western Poland)

Abstract The article depicts the problem of river system development during the Middle Pleistocene Interglacial in the Bystrzyca River Valley (Sudetic Foreland, south-western Poland). Ten research sites located within the Świdnica Plain are presented, in which the structural, grain size (granulometry), petrographic, quartz grain morphoscopy, and heavy mineral analyses were carried out. The study results show the formation of piedmont fan deposits 2–8 km to the NE of the Sudetic Marginal Fault. The location of the fluvial deposits between the Sanian and Odranian tills indicates that they were deposited during the Holsteinian Interglacial (Krzczonów Formation, Mazovian; see Table 1). According toxthe lithofacies analysis, vast alluvial plains, composed of angular gravel grains in the south and of sands in the north, were deposited in the Sudetic Foreland in the environment of a very dynamic river. They are covered with a discontinuous layer of Odranian till. The petrographic spectrum shows 90–99% of local rocks, namely, Sudetic porphyry, Sowie Mts Gneiss and milky quartz, and 1–10% of Scandinavian rocks. In the proto-Bystrzyca river system, the existence of an oxbow lake in the distal part of the Krzczonów fan has been proved, which was developing at the end of the Holsteinian Interglacial. The continuity of the alluvial deposits is interrupted in the vicinity of Świdnica due to both the tectonic movements and the formation of the narrow tectonic graben of Roztoka–Mokrzeszów.

The rare Holsteinian (Mazovian) interglacial limnic deposits in the Książnica outcrop at Krzczonów (near Świdnica), Sudetic Foreland

The article presents the results of research on peats, muds and sands filling a palaeocavity within alluvial fans of the Bystrzyca River valley, in the Sudetic Foreland of SW Poland. In the 534-cm deep research profile in the central part of a palaeolake, 267 samples were collected at an interval of 2 cm and lithologically (structural and textural studies), palaeobotanically (studies of diatoms, pollen plant macrofossils and fossil wood), palaeozoologically (Cladocera, Mollusca and Ostracoda), geochemically (chemical elements and isotopes) and palaeomagnetically analyzed.The profile consists of three parts: organic with mineral layers (lower), mineral (middle), and organic (upper). The palynological diagram was divided into three zones that represent local sets of pollen zones. This diagram, although incomplete, is clearly indicative of the younger part of the Holsteinian (Mazovian: pollen III and IV periods interglacial). The upper part of the diagram consists of four local pollen zones that are correlated with stadial and interstadial periods. Analysis of several samples of fossil wood shows the widespread presence of Pinus remains and numerous fragments of rhytidome (bark) of Betula. Development of the peat layer (1.36–0.68 m depth) started with paludification of the forest with the Betula forest. Analysis of Cladocera shows the presence of chitin armor components (species: Chydorus sphaericus, Alona rectangula and ephippia of Alona rectangula) in three samples.Lithological, Cladocera and palaeo-magnetic research, supported by geochemical studies, indicate the existence of at least three main phases. The lake originated during the younger part of the Holsteinian (Mazovian) Intergalcial as an oxbow within the valley, where the deposition of variously thick (up to 1.5 m depth) peats, organic and minerogenic silts (the first stage). In the second phase, a closed, fairly deep late Holsteinian lake continued to exist under relatively warm conditions with mainly mineral deposition from the slope. The lake became shallower and wider, and then more open and better oxygenated (with through-flow). In the final phase the lake was completely filled by organic sediments under interglacial conditions. The absence of diatom, molluscan and ostracod communities indicates an acid lacustrine environment at this time. The fluvial and limnic deposits are sealed by overlaying Saalian (Odranian) till.

Snow cover and its variability in the Polish Sudetes Mts. and the Sudetic Foreland

The paper presents the snow cover characteristics in the vertical profile of the Polish Sudetes Mountains and their foreland during the period of 1965/66–2007/08. The analysis was based on the number of days with snow cover ≥ 1 cm and its depth in a month, winter season (December–February) and entire year (season). Data was collected at 20 weather stations operated by the Institute of Meteorology and Water Management. The maximum depth of snow cover in the foreland and lower parts of the Sudetes Mountains was recorded in January, in higher parts of the mountains in mid-February or in March. On the average, the maximum depth of the snow cover varied from ca. 15÷25 cm in the foreland zone and lower slopes up to 120÷150 cm in the upper slopes and mountain tops. During the multi-annual period of 1951/52–2007/08, the maximum depth of snow cover showed a small decreasing trend, statistically insignificant at the 0.05 level, in 4 representative stations in the vertical profile of the Sudetes Mountains.

The first stages of erosion by ice sheets: Evidence from central Europe

In almost all former and presently glaciated areas of the world, glaciers have modified or even transformed pre-glacial terrain during the many cold stages of the Pleistocene. In consequence, the early stages in the development of glacial landscapes have been overprinted or erased by later phases of erosion. The Sudetes in central Europe provide exceptional opportunities to examine the inception of glacial erosion. Evidence of a long geomorphic evolution before glaciation, with the development of etch surfaces, deep weathering covers and the preservation of Neogene kaolinitic sediments, provides a direct analogue to other lowland crystalline terrains as existed immediately prior to Pleistocene glaciation. Large granite intrusions exist in the Sudetes and its Foreland that support hills that range in size from small tors to large domes. These terrains experienced only thin ice cover for short periods when the Scandinavian ice sheet reached its Pleistocene maximum limits in Marine Isotope Stage (MIS) 12 (Elsterian) at 440–430 ka and MIS 8 (Early Saalian) at 250–240 ka. In each of four study areas beyond, at and within the limits of glaciation we have mapped Glacial Erosion Indicators, glacial landform assemblages that indicate progressive glacial modification of the pre-glacial granite terrain. We find that glacial erosion increases with distance from the ice margin, due to greater ice thickness and longer ice cover, but has had only limited impact. On hills, regolith was stripped by moving ice, tors were demolished, and blocks were entrained. However, indicators of more advanced glacial erosion, such as lee-side cliffs and glacial streamlining, are absent, even from granite domes that lay beneath ~ 500 m of ice. The survival of tors beneath ice cover and the removal of tor superstructure by glacial erosion are confirmed. The presence of glacially-modified tors in areas covered only by Elsterian ice implies that the tors existed before 440 ka. Moreover, the contrast between blockfield-covered slopes found above Elsterian and Saalian glacial trimlines on summits of granite, gabbro and basalt hills in the Sudetic Foreland and glacially-stripped surfaces at lower elevations implies only limited regeneration of blockfields since 430 and 240 ka. The first stages of roche moutonnée formation are recognised in the exhumation of tor stumps but development of lee-side steps remains very limited. Granite domes retain a pre-glacial morphology and local examples of hill asymmetry are determined by structural, rather than glaciological controls. Development of roches moutonnées and asymmetric and streamlined hills by glacial erosion has not occurred in the Sudetes despite the passage of largely warm-based ice sheets 80–500 m thick that persisted for 5–20 ka.

Geoheritage and geotourism potential of the Strzelin Hills (Sudetic Foreland, SW Poland)

The aim of this paper is to present a state of knowledge about geotourism potential of the Strzelin Hills. Still there is no geotouristic infrastructure in the Strzelin Hills that could make available all their advantages for educational purposes. There are being carried out works on inventory and documentation to create a base for a development of geotourism. The geotouristic potential is described on the basis of previously studied and valorized objects of geological and geomorphological heritage. There were inventoried 38 objects of geoheritage. During valorization of 17 geosites and geomorphosites were selected 8 represented objects, which present 10 from the 15 thematic groups. There were briefly described 6 of them in this paper. .

Neotectonic development of drainage networks in the East Sudeten Mountains and monitoring of recent fault displacements (Czech Republic)

This paper presents results of morphotectonic research carried out in order to determine the neotectonic development of the drainage network in the NE spur of the Bohemian Massif (central Europe). The area studied comprises the north-eastern sector of the Rychlebské Mts, belonging to the Sudeten Mountains and the adjacent part of the Žulovská Hilly Land in the Sudetic Foreland (Czech Republic). Analysis of drainage network characteristics such as cross-sections, erosion rate, longitudinal river profiles, stream length-gradient index (SL) and investigation of alluvial fans/terraces was performed using detailed geomorphological mapping and field examination, and DEM data. Moreover, a reconstructed neotectonic evolution was compared with present-day fault movements obtained by fault monitoring using the TM71 deformeter. The deformeter was installed directly across faults in two karst caves in the study area within the NW–SE striking Sudetic Marginal Fault (SMF) zone. This zone is one of the morphologically most prominent neotectonic structures in central Europe, separating the Sudeten Mountains from the Sudetic Foreland. Morphotectonic research reveals that segments of enhanced erosion correspond well with increased SL indices, changes in valley cross-sections and anomalies in the longitudinal profiles. The beginnings of the stretches of increased headward erosion/rejuvenated erosional phase are concentrated at the foot of marginal slopes of the mountainous sector of the study area, which supports the hypothesis that uplift of the mountainous sector is still expressed in its relief. Alluvial fans/terraces of three levels recognized in the adjacent Žulovská Hilly Land are of Middle to Late Pleistocene age: Saalian 1 (240–280 ka), Saalian 2 (130–180 ka) and Weichselian (10–80 ka), respectively. They postdate the retreat of the last continental ice-sheet, which reached the study area in Elsterian 2 (400–460 ka). Their relative heights above the river channel are greater than terrace levels of the same age along the main Nysa Kłodzka River. The height differences attain 20 m at the highest level 1, at least 8 m at level 2, and up to 2–3 m at level 3. These discrepancies imply post-Saalian 1 uplift of the Žulovská Hilly Land relative to the topographically lower Nysa Kłodzka valley. Monitoring of present-day tectonic movements in the studied area revealed slow micro-displacements (hundredths to tenths of millimetres per year). The displacements have an aseismic character and the vertical component always prevails over the horizontal one. The inferred compressive stress comes generally from the southern sector, which would imply dextral transpression in the studied portion of the SMF, where the northern part is thrusting over the southern one. The trend of these present-day movements corresponds well with uplift of the studied area north of the SMF, which is also indicated by analysis of the drainage network. It is concluded that in areas of low tectonic activity the detailed study of individual characteristics of the drainage network, particularly their spatial relationships, as well as monitoring of fault micro-displacements can reveal rates and kinematics of ongoing tectonism.

Topography of a composite relict rock glacier, ślęża massif, sw poland

A detailed geodetic survey and, additionally, a map of slope covers have been carried out for a composite relict rock glacier on the slopes of Mt Ślęża (718 m a.s.l.), Sudetic Foreland, SW Poland. The survey allows one to distinguish the mobilisation, transition and accumulation zones and to define geomorphic features diagnostic for relict rock glaciers such as lateral ridges standing above a central depression, steep margins of the landforms in the transition and accumulation zones, as well as absence of distinct head scarps above. Furthermore, it indicates that the present‐day hydrographic pattern on the surface of relict rock glaciers has been superimposed on the relief inherited from the active landforms. The topography indicates that tension prevailed rather than compression during the development of the rock glaciers. Some of the features, such as small lateral lobes, developed probably as a result of the compressive flow, however. The pattern of the slope cover shows that it developed during activity of the rock glaciers and been modified afterwards due to solifluction.

Inherited landscapes of the Sudetic Foreland (SW Poland) and implications for reconstructing uplift and erosional histories of upland terrains in Central Europe

Abstract This paper provides evidence of the very varied denudation topography that had developed in the Sudetic Foreland by the end of the Palaeogene and which has survived up to the present day because of partial burial by Neogene sediments. The Sudetic Foreland comprised different landscape units and the range of relative relief within it may have been up to 600 m; 150–200 m seems to be a figure typical for the mid-Tertiary. This stands in apparent contrast to the widely held opinion that the landscape subjected to the Neogene uplift represented a planation surface. It is argued that much of the present-day topography of Central European uplands and mountains, including the adjacent Sudetes, may be inherited from the Early Cenozoic. In many cases there is generally no need to invoke complicated uplift histories, for which scarce independent geological evidence exists, to explain the origin of landsurfaces.

Kinematic data on major Variscan strike-slip faults and shear zones in the Polish Sudetes, northeast Bohemian Massif

The still highly disputable terrane boundaries in the Sudetic segment of the Variscan belt mostly seem to follow major strike-slip faults and shear zones. Their kinematics, expected to place important constraints on the regional structural models, is discussed in some detail. The most conspicuous is the WNW–ESE Intra-Sudetic Fault Zone, separating several different structural units of the West Sudetes. It showed ductile dextral activity and, probably, displacement magnitude of the order of tens to hundreds kilometres, during late Devonian(?) to early Carboniferous times. In the late Carboniferous (to early Permian?), the sense of motion on the Intra-Sudetic Fault was reversed in a semi-brittle to brittle regime, with the left-lateral offset on the fault amounting to single kilometres. The north–south trending Niemcza and north-east–southwest Skrzynka shear zones are left-lateral, ductile features in the eastern part of the West Sudetes. Similarly oriented (northeast–southwest to NNE–SSW) regional size shear zones of as yet undetermined kinematics were discovered in boreholes under Cenozoic cover in the eastern part of the Sudetic foreland (the Niedźwiedź and Nysa-Brzeg shear zones). One of these is expected to represent the northern continuation of the major Stare Mesto Shear Zone in the Czech Republic, separating the geologically different units of the West and East Sudetes. The Rudawy Janowickie Metamorphic Unit, assumed in some reconstructions to comprise a mostly strike-slip terrane boundary, is characterized by ductile fabric developed in a thrusting regime, modified by a superimposed normal-slip extensional deformation. Thrusting-related deformational fabric was locally reoriented prior to the extensional event and shows present-day strike-slip kinematics in one of the sub-units. The Sudetic Boundary Fault, although prominent in the recent structure and topography of the region, was not active as a Variscan strike-slip fault zone. The reported data emphasize the importance of syn-orogenic strike-slip tectonics in the Sudetes. The recognized shear sense is compatible with a strike-slip model of the northeast margin of the Bohemian Massif, in which the Kaczawa and Góry Sowie Units underwent late Devonian–early Carboniferous southeastward long-distance displacement along the Intra-Sudetic Fault Zone from their hypothetical original position within the Northern Phyllite Zone and the Mid-German Crystalline High of the German Variscides, respectively, and were juxtaposed with units of different provenance southwest of the fault. The Intra-Sudetic Fault Zone, together with the Elbe Fault Zone further south, were subsequently cut in the east and their eastern segments were displaced and removed by the younger, early to late Carboniferous, NNE–SSW trending, transpressional Moldanubian–Stare Mesto Shear Zone.

Glaciotectonic deformation during the Elsterian ice‐sheet advance at the northeastern margin of the Sudetic Foreland, SW Poland

The glaciotectonic deformations near the northeastern margin of the Sudetic Foreland, SW Poland. were formed during one glacial episode. They are relatively small and are truncated. Deformation structures have no recognizable relationship to the thick Neogene clay in the basement; they have variable relations to the morphology and indicate transverse to opposite directions of the glacial push in very small areas within a distance of 2 to 5 km. This suggests an unusual deformational history. Deformations have probably been created due to sliearing en masse of the anisotropic sediments and during the ice‐sheet advance. Deformation structures have been formed a few kilometres ahead of the curved ice margin, which created ‘glaciotectonic hills’ with strongly differentiated orientations of thrust structures and folds.

The Oligocene and Miocene Outliers of West Cornwall and their Bearing on the Geomorphological Evolution of Oldland Britain

The Tertiary sediments preserved at St Agnes, Crousa Downs and Polcrebo Downs, Cornwall, are described in detail. The deposits at St Agnes have yielded two contrasting floras, one mid-Oligocene, the other Miocene in age. The latter appears to be the first recorded proven Miocene extant in the British landscape. Accordingly, it has become necessary to distinguish two discrete outliers at St Agnes: that termed the St Agnes Formation sensu stricto (Miocene) and the Beacon Cottage Farm Formation (Oligocene, the local equivalent of the Bovey Formation). A tripartite stratigraphy is proposed for the former, the upper and lower Members comprising wind-blown sands and the middle Member a colluvial slope-wash deposit; all were apparently formed under warm-temperate conditions. The sediments at Crousa and Polcrebo remain undated; both preserve deep weathering profiles of tropical or subtropical type in the Palaeozoic floor below and are themselves much affected by in situ deep weathering. Structurally, all four outliers appear to be simple erosional relics of once more widespread and, possibly, thicker sheets. No secondary structures have been identified. All four apparently survived as a result of their locations on prominent watersheds originating in at least mid- or even early Tertiary times. The geomorphological relations of the four outliers are considered in detail. The sub-St Agnes Surface is shown to be the homologue of a planation surface that is widely developed in west Cornwall at an elevation of between ca. 75-131 m above sea level (ASL). The latter is redefined and termed the Reskajeage Surface. Its age is shown to be pre-Upper Miocene rather than Pleistocene, as was previously widely held. There is indirect evidence that it formed subaerially over a long period during mid-Tertiary times; essentially, it appears to be an etchplain of tropical and subtropical origins, now largely stripped of its former saprolitic cover. It is demonstrated that the grosser physiography of west Cornwall was established by the end of the Palaeogene at the latest and, also, that the area has probably never been inundated by Tertiary seas, except shallowly near to the end of that period (i.e. by the St Erth transgression). The prolonged morphodynamic stability of the region, as established in this paper, has important consequences for the interpretation of landscape evolution elsewhere in areas of Oldland (i.e. post-Armorican) western Europe, especially where datable Tertiary deposits have yet to be recognized.

On the Zechstein Copper Shale lithofacies and palaeoenvironments in SW Poland

Summary Microfacies and geochemical studies on the Copper Shale in the Sudetic Foreland of SW Poland show the strong influence of palaeorelief on the distribution of lithofacies. Spatial variability in microlithofacies and lithofacies indicate sedimentation in the following palaeoenvironments: (1) offshore—deep shelf, characterized by the black shale lithofacies (30–50 cm thick) and shallow shelf, where the Copper Shale is either absent or is represented by red shale lithofacies (up to 60 cm thick), and (2) nearshore, characterized by grey shale lithofacies (40–100 cm thick or more). Shorewards the Copper Shale is replaced by carbonate and/or terrigenous rocks of the first Zechstein cycle.

The sedimentation of copper-bearing shales (Kupferschiefer) in the sudetic foreland

The profile of the copper-bearing shales (Kupferschiefer) displays 3 types of lithological developments of the Sudetic Foreland: Many horizons of concentration of copper, lead and zinc are present. The concentrations of copper sulphides occur in lagoonal areas in which an oxigen deficiency was associated with a great amount of organic matter. The beds formed in the oxidation facies represent the coastal zones of an open sea basin where the influence of inflow and outflow were considerable.

Problems of migration of Polish crude oils on the basis of geochemical correlation data and carbon isotope composition

A method for the correlation of crude oils has been worked out on the basis of analyses of 120 crude oils from 4 geological regions of Poland. The first stage of the correlation consists in selection of crude oils into groups or families on the basis of structural and group composition of the hydrocarbon part of the crude oil, i.e., on its Y and X values. The family consists of crude oils which undergo the same chemical metamorphism and derive from the same source material. The second stage of the correlation refers to a differentiation of crude oils, within the family, according to their degree of metamorphism. In the third stage, probability calculus has been applied with the aim of distinguishing crude oils of about the same age (generations of crude oils). The results of the correlation made in 4 regions are presented, as is also the carbon isotope composition of 35 crude oils. Geochemical and geological data have been compared and conclusions have been drawn from these. Carboniferous sediments have been estimated as source rocks for crude oils from the Carpathian flysch and the Carpathian foreland. Formation of the older generation ( A) of crudes began in the Early Cretaceous; that of the younger generation ( B) in the older Pliocene. Silurian sediments have been estimated as source rocks for crude oils from the synclinorium of Lublin. Formation of the crudes began in the Late Carboniferous. The Hauptdolomite of the Zechstein is regarded as a source rock for crude oils from the Sudetic foreland monocline. Formation of these crudes began in the Jurassic, and migration and accumulation occurred within the source rocks. Migration channels in each region are discussed and perspective areas for crude oil exploration are proposed.