Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 53

Liczba wyników na stronie
first rewind previous Strona / 3 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 3 next fast forward last
EN
A concise stratigraphic synthesis of the Grajcarek Succession of the Pieniny Klippen Belt (West Carpathians,Poland) is presented. This succession consists of 12 lithostratigraphic units with the rank of formation, and two with the rank of member, spanning the geological time from middle Toarcian (late Early Jurassic) to Maastrichtian (Late Cretaceous) and mid Paleocene. The stratigraphical column starts with deep-water flysch (the Szlachtowa Fm; Toarcian–Aalenian through Bajocian–?lower Bathonian), followed by dysoxic shales, marls and limestones (the Opaleniec Fm; Bajocian–Bathonian). The previously distinguished Krzonowe and Stembrow formations, are downgraded to members. Late Bathonian–Oxfordian times were characterized by the widely occurring deposition of abyssal radiolarites and shales, which is represented by the Sokolica Radiolarite Fm and the Czajakowa Radiolarite Fm, common to both the Grajcarek and Klippen successions. Red nodular limestones and aptychus marls (the Czorsztyn Limestone Fm; Kimmeridgian–lower Tithonian) overlie the radiolarites. Above, pelagic cherty limestones occur (the Pieniny Limestone Fm; Tithonian–Aptian). These are followed by Lower Cretaceous predominantly dark shales and marls (the Kapuśnica Fm; Aptian–Albian, the Wronine Fm; Albian, and the Hulina Fm; Albian–Cenomanian), succeeded by abyssal, red shales (the Malinowa Shale Fm; upper Cenomanian–Campanian), and these in turn by grey, marly, flyschoid strata (the Hałuszowa Fm; ?Campanian). The Grajcarek Succession terminates with the Jarmuta Fm (Maastrichtian–mid Paleocene). It consists of sedimentary breccias, often with large olistoliths of Jurassic–Cretaceous rocks, and conglomerates and sandstones in a southern zone, giving way to proximal flysch and distal flysch facies further north. This was the time of orogenic Laramian folding events, associated with subaerial and submarine erosion. A sedimentary hiatus separates the Jarmuta Fm flysch (Maastrichtian) from the Szczawnica Fm (Upper Paleocene–Eocene) in both the Klippen and Grajcarek successions. This hiatus seems to diminish and finally close in a northward direction, in the Magura Nappe succession.
EN
This paper describes sedimentology and palynology of freshwater plant-bearing late Cenozoic (Pliocene sensu lato) deposits drilled at Mizerna, the eastern part of the Nowy Targ Intramontane Depression, West Carpathians, South Poland. Our data were obtained from a newly-analysed 39-m thick succession from the Mizerna-Nowa borehole, containing spores, pollen and freshwater organic-walled algal micro-remains. They shed light on the palaeoenvironmental conditions of the Nowy Targ Intramontane Depression, where the Mizerna palaeolake once formed.
EN
The paper presents core description of the Maruszyna IG-1 Deep Borehole located in the southernmost part of the Pieniny Klippen Belt of Poland, at the Kraków-Zakopane geotraverse of the Polish Carpathians. In the borehole, two Laramian nappes have been recognized: the Pieniny Nappe, PN (0 down to 930-960 m below the surface), and the Branisko Nappe, BN (1225-4843 m below the surface). The rocks of the Branisko Nappe are unconformably covered by the Maastrichtian marine molasse (conglomerates with large olistoliths derived from this nappe) - the Jarmuta Formation, JmF (930-1190 m below the surface). The Laramian overthrust zone: PN over JnF (and BN) lies at 930-960 m below the surface. The Branisko Nappe is subdivided into three first-order (major) and numerous, second-order (minor) tectonic scales. 29 samples from the Middle Jurassic, Lower and Upper Cretaceous rocks have been analyzed for palynofacies and organic-walled dinoflagellate cysts. Biostratigraphic interpretation of dinoflagellate cyst assemblages generally confirms the ages of the earlier-distinguished Jurassic and Cretaceous lithostratigraphic units in this borehole. An Aalenian dinoflagellate cyst assemblage from rocks attributed to the Harcygrund Shale Formation, suggests a slightly wider time-range of this unit than hitherto assumed: Aalenian-Lower Bajocian.
EN
Stratigraphic sequence of the Lower Subtatric Succession in the eastern part of the Polish Tatra Mountains includes 15 Triassic, Jurassic and Lower Cretaceous mappable lithostratigraphic units of formation ranks. Some formations include also non-mappable lithostratigraphic units of local significance, of member and bed ranks. This stratigraphic succession is typical of the Lower Subtatric Nappe (= Križna Nappe) which originated during the meso-Cretaceous (Turonian) Mediterranean orogenic phase. The older post-nappe cover (?Upper Cretaceous or ?Paleocene-Lower Eocene), unconformable upon the Lower Subtatric Nappe, is represented by an unfossiliferous Gosau-facies conglomerate (Rusinowa Fm.) consisting of Triassic to Lower Cretaceous rock fragments derived from this nappe. The Lower Subtatric Nappe has been subdivided into several second-order thrust-sheets (partial-nappes vel daughter units) of restricted lateral extension, thrust one over another from north to south (retro-arc). The Gosau-facies conglomerate (Rusinowa Fm.) takes part in the thrust-sheet architecture which was accomplished in the Tatra Mts prior to the Middle Eocene transgression, either during the Laramian (Cretaceous/Paleocene boundary) or the Pyrenean (Middle Eocene) orogenic phases. The younger post-nappe cover consists of the Middle Eocene basal conglomerates and nummulitic limestones succeeded by a thick Podhale Flysch complex (Oligo- cene). A dense transversal (vertical to strike-slip) fault system which dissects rocks of the Lower Subtatric Nappe, its daughter units and post-nappe covers, had formed due to meridional stress active during the Middle Miocene.This fault system plays an important part in correct recognition and correlation of particular tectonic units.
EN
TheMizerna site (Polish Western Carpathians) is one of the most important Pliocene palaeobotanic sites in Central Europe. Its fresh-water deposits, laid down in a buried river valley, were studied in detail more than half a century ago in natural exposures and shallow boreholes, prior to partial drowning of the area by an artificial lake. The deposits yielded a very rich macrofossil plant collection elaborated in detail by Szafer (1954) who claimed that they represented a continuous succession of the Pliocene through Early Pleistocene plant communities. First palynological examination of the Mizerna deposits (by Oszast) was made more than half a century ago. Re-evaluation of stratigraphic and palaeoclimatic significance of macrofossil plant remains, along with a reassessment of palaeoenvironmental and sedimentary conditions during formation of the Mizerna fresh-water deposits, is in progress. This may help elucidate the problem whether the Mizerna sediments represent both the Pliocene and Early Pleistocene or, solely, the Pliocene successions.
6
Content available Antropocen : nowa epoka geologiczna?
EN
The Anthropocene is a new epoch proposed by Crutzen and Stoermer (2000), with a base at 1950 AD or 1800 AD. The present author doubts its value while studying Quaternary stratigraphic columns, as its base signal (Holocene/Anthropocene) might be unrecognizable in field sections. The usage of the Anthropocene epoch would probably be restricted to areas of massive direct negative human impact on Nature, predominantly in the Northern Hemisphere. In much less affected Southern Hemisphere deserts (Australia), mountain chains (the Andes), the near-pristine glaciated Antarctic continent and Subantarctic islands, separation of the Anthropocene time-unit (as a formal epoch) from the Holocene epoch would be artificial, even useless. On the other hand, the informal term might be useful for economic geographers, planners, sociologists, and Nature- protectionists.
EN
This article presents the sixth and final contribution in a series of papers focused mainly on the K-Ar dating of the Oligocene and Neogene (Miocene and Pliocene) intraplate basaltic volcanics of the Lower Silesia, SW Poland. The present paper includes 22 new K-Ar dates from the West Sudety Mountains and their northern foreland. The K-Ar dates range from 30.7 to 22.2 Ma. The data are supplied with geological description of the sampled outcrops, petrographic, geochemical and palaeomagnetic data of the analysed samples. Palaeomagnetic investigation confirmed the existence of two important volcanic episodes distinguished already in 1997: the reversed polarity Odra Event (mean age 28.2š1.2 Ma), and the normal polarity Gracze Event (mean age 26.28š1.8 Ma).
EN
The Upper Proterozoic meta-diamictites (Kapp Lyell Formation) exposed south of Bellsund, central Spitsbergen, believed by many authors to represent the Vendian (Varangian) glacial tillites, have been investigated. Character of their relictic sedimentary features does not confirm, however, its glacial origin. The diamictites formed mainly as debris-flow and slope-creep terrestrial covers derived from frost-shattered steep rocky margins of a predominantly fresh-water depositional basin. The deposition took place under seasonally differentiated moderate-cool climatic conditions comparable to the modern Subarctic periglacial zone, however outside the reach of glaciers and ice-sheet. Uncommon finer-grade varved deposits containing haphazardly distributed clasts (drop- stones) probably formed in shallow fresh-water lakes that froze during winter; the clasts were subsequently dispersed during summer in the lakes as ice-rafted dropstones. Shallow erosional channels infilled with sandstone within the diamictite complex, might be evidences for braided river systems that were active during summer. Rare, well-rounded cannonball-size cobble/boulder beds represent a fossil high-energy, probably marine beach.Uncommon thin limestone intercalations, found in a predominantly coarse-clastic suite, might suggest occasional incursions of a shallow sea.
9
Content available remote Coals of the Calypsostranda Group (Palaeogene) at Bellsund, Spitsbergen
EN
Numerous thin coal seams occur in terrestrial deposits of the Skilvika Formation, Calypsostranda Group (Late Palaeogene), at Bellsund, central Spitsbergen. According to coal-petrographic study, they mainly belong to the vitrinite-fusinite facies. At Calypsostranda (Tyvjobekken), Calypsobyen (abandoned coalmine) and Skilvika (coastal main section), they are represented mainly by telocollinite subfacies which developed in a wet forest swamp at high groundwater level condition (the "shale with coal streaks" subfacies) close to a delta distributary or main river channels. At Rensdyrbekken (NW Calypsostranda), an increased share of herbaceous swamp facies was recognized in coal formation: a sapropelic coal facies was generated there under condition of inner parts of interchannel lakes.
EN
Description of selected Jurassic-Cretaceous field sections of the Branisko Succession (Nappe) deposits exposed in the Czorsztyn Range, Pieniny National Park (Pieniny Klippen Belt, West Carpathians, Poland), is presented. Some klippes, previously attributed to the Czertezik Succession, are now revised as belonging to the Branisko Succession.
EN
A succession of residual moraine covers and glaciomorphological forms, correlatable with the Pleistocene Mindel, ?Riss and Würm glaciations, and superimposed glacial/nival moraines and morphological forms (Late-Pleistocene/Early Holocene), have been distinguished between the Biała Woda and the Filipka valleys, Polish Tatra Mts. Their stratigraphic ages are discussed in the regional context.
EN
A new for mal lithos tra tigraphic name, the Szopka Lime stone For ma tion, is in tro duced for fos si lif er ous spotty lime stones (Fleck enkalk fa cies) of Up per Li as sic (Up per Pli ens ba chian = Domerian) age, de vel oped in pe lagic basi nal suc ces sions of the Pi en iny Klip pen Belt of Po land (West Car pa thi ans). The for ma tion oc curs pre domi nantly in the Pi en iny Suc ce sion, but has also been rec og nized in a south ern va ri ety of the Brani sko Suc ces sion.
EN
The fossil flora from Hope Bay, West Antarctica, is ranking among the richest Jurassic floras of the world. So far, it was known mostly from loose blocks scattered at coastal plain below Mount Flora. The present collections from the Mount Flora Formation, include the fossil plants assembled mainly in situ (from the Flora Glacier Member), but also those obtained from loose blocks (derived from the Five Lakes Valley Member and the Flora Glacier Member). 41 plant taxons were identified: 2 from Hepatophyta, 2 from Sphenophyta, 9 from Pteridophyta, 5 from Pteridophylla, 6 from Pteridospermophyta, 9 from Cycadophyta and 8 from Coniferophyta. The taxons new for Antarctica include the species Coniopteris cf. simplex (Lindley & Hutton) Harris, Equisetum cf. columnare Brongniart emend. Harris, Otozamites gramin eus (Phillips) Harris, and the genera Conites Sternberg emend. Cleal et Rees and Stachyotaxus Na thorst. New taxa include: Crosso zamiamirabilis sp. nov. Ociepa and Pagiophyllum arctowskii sp. nov. Ociepa (Schizole pidella birkenmajeri sp. nov. Ociepa, 2007, has been described separately). A new combination Araucarites antarcticus (Gee) comb. nov. Ociepa is presented. The described flora confirms its Jurassic age. The paper presents also remarks on palaeoclimate and environment of the Antarctic Peninsula volcanic arc during the Jurassic.
EN
Geochemical analysis of a basaltic olistolith, K-Ar dated at Lower Cretaceous, which occurs in Upper Cretaceous conglomerates (Jarmuta Formation) of the Pieniny Klippen Belt of Poland, points to trachybasalt field of intraplate basaltoids. The olistolith most probably derived from a volcanic structure located on the Czorsztyn Ridge - a lithospheric splinter of the North European Platform which, during Jurassic-Early Cretaceus, bordered the Pieniny Klippen Belt Basin from the north.
EN
Distribution of karst sink-holes developed in morainic deposits of the Würm Glaciation in outer part of the Sucha Woda Valley, Polish Tatra Mts (Carpathians), indicates much wider subsurface extension of Triassic limestones than that shown on geological maps of the area.
EN
The stratigraphic column of the Czertezik Succession (Pieniny Klippen Belt, West Carpathians) includes Upper Liassic through Upper Cretaceous rock units. The succession crops out in several tectonic windows from below the Pieniny Nappe and/or the Branisko Nappe which were thrust over the Czertezik Unit during Laramian folding of the Klippen Belt. Lithological development and succession of strata of the Czertezik Unit in these windows prove that its original sedimentary zone was a direct southern continuation of the Czorsztyn one. In the present author's opinion, contrary to Wierzbowski et al. (2004), the Czertezik Succession in the territory of Poland lacks the Bajocian-Callovian ammonitico rosso unit = the Niedzica Limestone Formation. The Czorsztyn Limestone Formation (Kimmeridgian, also ammonitico rosso facies) distinguished by the present author in the Czertezik Succession at Czertezik and Pieniński Stream (Pieniny Range), and at Wysoka Mt (Little Pieniny Range), attributed by Wierzbowski et al. (2004) to the "Niedzica Limestone Formation", did not yield any age-diagnostic fossils to support their change of its Kimmeridgian (resp. Oxfordian-Kimmeridgian) age to an Upper Bajocian-Callovian one. This limestone occurs always above, and not below the radiolarite horizon (Czajakowa Radiolarite Fm.). In the present author's opinion, two klippes with fossiliferous Niedzica Limestone Formation described by Wierzbowski et al. (2004) from Litmanová and Milpoš, East Slovakia, do not represent the Czertezik Succession but are typical examples of the Niedzica Succession. A palinspastic-sedimentological model proposed in this paper shows probable Middle Jurassic palaeogeographic position of the very discontinuous sedimentary area of the Niedzica Succession, between larger submarine crinoid limestone fans developed in the Czorsztyn and Czertezik sedimentary zones.
EN
A geological section on Mt Hulina at Szczawnica Niżna, the Małe Pieniny Range, exposes Jurassic through Cretaceous rocks of the Grajcarek Unit, the northernmost tectonic unit of the Pieniny Klippen Belt (West Carpathians, Poland). Dark marine shales of very similar lithology, but with different microfossil assemblages, occur twice in the section, representing the Middle Jurassic (Opaleniec Formation) and the Lower Cretaceous (Wronine Formation) units of the Magura (Grajcarek) Succession, respectively. This paper presents the results of dinocyst investigations from the Opaleniec Formatiom which indicate its Bathonian age, and the Sokolica Radiolarite Formation which point out to their Middle Oxfordian - ?Lower Kimmeridgian age.
EN
This is the fifth contribution to geochronological, petrologic-geochemical and palaeomagnetic studies of the Tertiary basaltoids of Lower Silesia, Poland. It covers the area of the North-Sudetic Depression close to its contact with the Fore-Sudetic Block (6 new sites). The oldest K-Ar date was obtained from basanite plug at Sichów (BP-34: 27.80ą1.27 Ma) located exactly on the Sudetic Marginal Fault. It determines the age of the fault as Late Oligocene. Five other sites (BP-35-39) yielded radiometric ages between 20.07ą0.90 Ma and 18.72ą0.81 Ma (Early Miocene). The volcanics investigated are typical within-plate basaltoids represented by ankaratrite and basanite. The Late Oligocene Sichów intrusion (BP-34) is normally magnetized, the Early Miocene basaltic rocks (ankaratrite BP-39 and basanites: BP-35-38) reveal reversed magnetization.
PL
Piąta część datowań K-Ar i badań paleomagnetycznych trzeciorzędowych wulkanitów Dolnego Śląska obejmuje odsłonięcia tych skał w obszarze niecki północnosudeckiej, w sąsiedztwie sudeckiego uskoku brzeżnego. Otrzymano sześć dat w granicach 27,80š1,27 Ma (późny oligocen: Sichów, BP-34) – 18,72š0,81 Ma (niższy miocen = burdygał: Wilków, BP-37). Późnooligoceńska data dla ankaratrytowego czopu Sichowa (BP-34), który znajduje się na sudeckim uskoku brzeżnym, określa taki wiek tego uskoku. Zbadane skały bazaltowe – bazanity i ankaratryty (melabazanity) są typowymi przedstawicielami wulkanizmu sródpłytowego. Skład chemiczny ogniska magmowego podlegał ewolucji, co przejawiło się w badanych skałach wzrostem zawartości potasu i kobaltu w okresie czasu między wyższym oligocenem a niższym miocenem. Czopy ankaratrytu i bazanitu zostały zbadane pod względem paleomagnetycznym: najstarszy z nich, 27,80 Ma (BP-34: ankaratryt) wykazuje namagnesowanie normalne, pozostałe pięć, 20,07–18,72 Ma (BP-39: ankaratryt; BP-35–38 – bazanity) wykazuje namagnesowanie odwrócone.
first rewind previous Strona / 3 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.