This volume of 30 chapters authored by 107 geologists and geophysicists from Austria, Czech Republic, Hungary, Poland, Romania, Slovakia, Ukraine, United Kingdom, and the USA provides a comprehensive and understandable account of geology and hydrocarbon resources of the entire Carpathian system from northeastern Austria to southern Romania, including the Neogene foredeep, the foreland platform both in front and beneath the thrust belt, the Carpathian thrust belt, and the late and post orogenic intermontane basins. Principal chapters on regional geology are supplemented by thematic contributions on geodynamic reconstructions, regional geophysical investigations, hydrocarbon systems, and case studies of major oil and gas fields. To date, close to 7 billion barrels of oil and more than 53 trillion cubic feet of natural gas have been produced from the entire Carpathian system. Additional new reserves may be found, especially at deeper structural levels below the Neogene foredeep and the thin-skinned Carpathian thrust belt. Seventeen chapters of Memoir 84 have been printed in full. The remaining chapters have been printed as abstracts only, with the full paper for all 30 chapters as .pdf files on the CD-ROM in the back of this publication. The publication is intended as a source of information to schools, governmental and private institutions, oil companies, and potential investors.
ON THE AGE OF THE WĄCHOCK SANDSTONES In the northern periphery of the Świety Krzyz Mountain, in the region of and Suchedniow, hematite sandstones occur in the upper part of the Lower Triassic. Their range has not yet been determined, since their major part is covered by younger deposits; at any rate it is known that northwards they extend as far as the region of Studzianna. Hitherto the exact age of these sandstones has not been established, mainly due to the lack of fossils. However, recent research indicates that the hematite sandstones represent sediments of the Lower Roth. The author suggest the term Wąchock beds for the entire complex containing intercalations of these sandstones.
GEOLOGICAL STRUCTURE OF THE SILESIAN UNIT BETWEEN BILSKO AND TABASZOWA The investigated portion of the flank of the Roznow anticline reveals a complicated structure. Two parts may be distinguished there, the northeastern and the southwestern, which differ in their structures and tectonic directions. Furthermore, the southwestern part is loosened and overthrusted on the northeastern part. Dislocations running along the Dunajec and the Łososina valleys separate this element from the neighboring area. The lower and the upper Istebna beds are the oldest member exposed here. They contain exotics of effusive rocks (porphyries, dacite-andesites, felsites and greenstones), metamorphic rooks (granitogneisses, alaskites, psephitic and psammitic gneisses, garnetiferous shales, porphyroisdal gneisses and marbles) and sedimentary: rocks (planctonic, bryozoan-foraminiferal, lithotamnian and radiolarian limestones, as well as limestones with ammonites and flits). In these beds radial imprints of medusa-like forms resembling genus Kirklandia C a s t e r have been discovered. In some parts of these beds, numerous are bioglyphs of Paleobulia , Ceratophycus and Spirophyton types, and star-like feeding traces of annelids. Due to the tectonic disturbances the Ciezkowice sands tones had suffered a partial reduction, hence, only their lower part survived. Only higher up, the Globigerina marls occur, interstratified in their upper part by thick bedded sandstones resembling those from the Krosno beds. Subsequently, the menilite shales are present, covered by the Krosno sandstones.
ORIGIN OF LAMINATED SALT (LENS OF KLĘCZKI) WITHIN WIELICZKA OLISTHOSTOMES (CARPATHIAN FOREDEEP)
Summary
Within the upper part (salt breccia - Zuber) of the Wieliczka salt deposits (middle Miocene) there are lenses built up of conglomerates and laminated salt (Figs. 1-4). Hitherto it was belived that these lenses represent tectonic schuppen derived from stratified salt which underlies the breccia. Recent studies conducted in the Wieliczka salt mine shown that the breccia deposit is a series of olisthostromes (3) and laminated salt is an integral part of them.
The latter represents the uppermost part of the sequence deposited by a single sediment gravity flow. There is a continuous transition from olisthostroma via conglomerates into parallel and cross-laminated salt (ryc. 5, 8-14). In whole sequence there are randomly dispersed outsized blocks of Miocene claystones. The clastic material of conglomerates and laminated salt consists almost exclusively of salt pebbles, salt grains and broken salt crystals. In small quantities occur clasts of Miocene mudstones, quartz grains and Miocene foraminiferas (ryc. 6, 7, 9). The gravity flow started as cohesive debris flow which involved into surging high-density turbidity current. Fluctuations in the rate of suspended-load fallout resulted in sedimentation from traction carpet, traction and suspension (ryc. 16).
The complete sequence in the Wieliczka breccia deposit is remarkably rare, usually these deposits are represented by thick beds of sediments deposited by cohesive debris flows only or by debris flow associated with gravelly division of high-density turbidity current (pebbly mudstone + graded or inverted graded conglomerates).
The above mentioned mechanism of transport could been modified by influence of high density of salt water in which sedimentation took place.
Regional and local variation of composition of the sandstones of the Krosno beds (Flysch Carpathians) estimated by ariance analysis
The method of multivariate analysis of mineral composition (Krumbein and Tukey, 1956) was, used in the present study of the sandstones of the Krosno beds. The calculations were made with the use of the ELWRO ODRA 1204 computer, in the Computer Center of the Jagellonian University.
STRATIGRAPHY AND PALAEOGEOGRAPHY OF THE KROSNO BEDS OF THE SILESIAN SERIES OF THE CARPATHIAN FLYSCH
The present study is concerning the thick-bedded graded sandstones of the Lower Krosno beds of Oligocene age, in the Silesian Series of the Carpathian flysch. The lower boundary of the Krosno beds is diachronous in the sedimentary basin of the Silesian series, being stratigraphically younger in the north. In the southern and western part of the basin, the Lower Krosno beds are ending the flysch succession as the youngest beds present, while in the northern and eastern part of the basin they are covered by the Upper Krosno beds. The thick-bedded sandstones analysed in the present study form the basal member of the low er Krosno beds, and occur below the m arker horizon of the calcareous Jaslo shales. Therefore the analysed sandstones are roughly coeval in various parts of the sedimentary basin (Fig. 1). The sandstones of the Lower Krosno beds were deposited by turbidity currents, and the m ajo rity of beds is graded. Studies of palaeocurrent 'directions and facial development (Dzulynski and Ślączka, 1958), provided evidence that the clastic material of the Krosno beds was derived from various source areas. Two of these source areas are well individualized, namely the western source area — i. e. the Silesian cordillera of the Carpathian geosyncline, and the eastern source area, i. e. the Maramures massif. The third, north-western source, the presence of which is inferred from palaeocurrent directions in the Upper Krosno beds, and the presence of exotic pebbles and reworked flysch rocks, is somewhat less distinct than the two other ones. The main problem arising from these previous studies w as: to what extent the provenance of material is reflected in the composition of sandstones?
THE SAMPLING SYSTEM
The hierarchical sampling system was designed with the aim to separate the variation due to local effects from the regional variation of the mineral composition of the sandstones (Fig. 2). The sedimentary basin of the Lower Krosno beds of the Silesian series was divided into three regions, according to the provenance of the clastic material of the sandstones. Two cross sections, one proximal, the other distal with regard to the inferred position of the source area were selected in each region. Ten beds were sampled in each section. Two samples per bed w ere taken, one from the base, the other from the top of the bed. The regions and the location of the sampled sections are shown in Fig. 3. The sampling system perm its to analyse the variation of mineral composition on the following levels:
- between samples in the beds,
- between beds in the sections,
- between sections in the regions,
- between regions in the whole basin.
PETROGRAPHY
The mineral composition of the samples of sandstones was determined in thin sections; with the use of an ELTINOR point counter 200 points per thin section were counted. The content of the following 8 constituents was recorded: quartz, feldspars, micas, metamorphic rocks fragments, limestone fragments (bioclastic, micritic, sparitic limestones) zoogenic limestone fragments (Stramberg type), intraclasts (fragments of shales and fine-grained sandstones) and cement+matrix. The number of analysed samples was 120, and the total number of observations (determined content of a single component in a sample) amounted to 960. The composition of the analysed sandstones is presented on Table 1 and Table 2.
STATISTICAL HYPOTHESES
The results of the analysis of variance of the mineral composition of the sandstones of the Lower Krosno beds are presented in Table 3. The interactions of the various levels of hierarchical sampling and the mineral constituents were used to test the following statistical hypotheses (Snedecor’s F test):
1. Ho: the variation of composition between regions is not significantly greater than the variation between sections in the regions.
2. Ho: the variation of composition between sections in the regions is not significantly greater than the variation between the beds in the sections.
3. Ho: the variation of composition between beds in sections is not significantly greater than the variation between samples in beds.
4. Ho: the variation between samples in beds is not greater than the residual variation in a homogenous mixture of the constituents. These hypotheses w ere tested for individual regions, for pairs of regions and for all three regions. The results of tests of the statistical hypotheses are given in Table 3 and summarized in Table 4.
CONCLUSIONS
The first hypothesis is accepted for all pains of regions and all three regions. It is concluded, that the differentiation of material derived from the various source areas is small. The individual character of the eastern source area (region 3) is better marked by qualitative data on the range of rocks occurring among the fragments of metamorphic rocks and by the lack of zoogenic limestones than by the overall quantitative composition. The second hypothesis is rejected, and it is concluded, that the variation of composition between sections in the regions is greater than between the beds in the sections. This indicates, that the transport of the clastic material on the distance between the proximal and the distal section results in a composition sorting, which is presumably associated with size sorting and selective transportation of micas. The third hypothesis is rejected for the regions 1, 2, for the pair 1 and 2, and for all three regions. In these cases it is concluded that the variation of composition between beds in profiles is greater than between samples in beds. The geological interpretation of this conclusion comprises the following possibilities :
- the mineral composition is closely related with grain size, and the variation of grain size distribution parameters between beds is greater than the difference of grain-size distribution parameters at the base and the top of the graded beds. This may imply, that the competence of individual turbidity currents varied considerably;
- the variation of mineral composition with in a section is reflecting the erosion of the source area, and consecutive degradation of rocks diferring in petrographie character;
- the structure of the source area was complex and the composition of the clastic material deposited in the littoral zone before redeposition by turbidity currents varied in space and time; thus the individual turbidity currents originating at various points along the shores of the cordillera (e. g. in various submarine canyons) carried different material;
- all the above factors operated simultaneously. In the eastern region the variation of composition between beds in profiles is not greater than the variation between samples in beds. It is concluded that the eastern source had a more homogenous composition than the western source or sources. This individualizes the eastern source, while the presumed two western sources corresponding to the regions 1 and 2 do not display differences in their petrographie character. The more uniform character of the material from the eastern source is reflected also in the pairs of regions: 1 and 3, 2 and 3. The fourth hypothesis is rejected for all regions and all groups of regions. It is concluded therefore, that the mechanism of deposition of graded beds by turbidity currents effectively differentiates the composition of the detrital material. The sandstones of the Lower Krosno beds are characterized by a local variability and a regional homogeneity of their mineral composition. The local variability is related with the processes of transport and deposition of the clastic material by turbidity currents.
ABSTRACT Metresa is a thick, distinctive turburdite within the Menilite Shales in the Carpathians of south‐east Poland. It was deposited by a SE‐flowing turbidity current derived from the Silesian cordillera and can be traced for 55 km downcurrent; it has a width of at least 15 km. The current contained roughly 3 km 3 of sediment and conforms to the definition of a seismoturbidite. Grain‐size analyses of samples from the nine localities where Metresa is exposed indicate average velocities decreasing from 2 m s −1 to less than 1 m s −1 over the 55 km. Massive divisions are poorly developed; instead, the turbidite, although graded, tends to be laminated throughout. Flat lamination predominates with intercalated cross‐lamination and erosion structures at various levels. Small‐scale cross‐lamination, presumably associated with ripples, occurs at some upper levels. An exceptional feature is a large‐scale wave‐like structure somewhat resembling hummocky cross‐stratification. The structures are not consistent with the inferred velocities. It is suggested that the stability fields relating structures to stream power (herein called the ‘Allen fields’) are displaced in respect to deposition from waning turbidity currents.
An example of large scale bottom erosion in the flysch basin
W warstwach gornohieroglifowych faldow dukielskich zostala znaleziona lawica piaskowca z wyraźnymi śladami erozji dna morskiego, dzialającej prawie bezpośrednio przed osadzeniem tej warstwy. Ma to duze znaczenie dla określenia wielkości erozji dennej w czasie dzialania prądu zawiesinowego. W opisywanym przypadku co najmniej 2 m osadu zostalo usuniete bezpośrednio przed osadzeniem sie lawicy piaskowca.
A sandstone layer with distinct traces of bottom erosion on its sole has been found in the Hieroglyphic beds (Paleocene — Lower Eocene) in the Carpathian flysch. This occurence may be important in the estimation of the amount of bottom erosion preceding the deposition of some turbidite layers in the flysch. It is tentatively suggested that at least 2 m. of mud have been washed away before the deposition of the bed described.
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