Apart from a few small remnants of the Turan Plate in the north, Iran during the Palaeozoic was part of the northern margin of Gondwana. On the basis of 65 sections, the majority of them covering the time-span from the Late Silurian into the Early Carboniferous, the stratigraphy and facies pattern of this area have been elucidated. Biostratigraphical calibration and correlation of the sections, mostly by means of conodonts and brachiopods, show the evolution from a shallow carbonate- dominated shelf in the Silurian which, by a drop of sea-level, was transformed into a siliciclastic shelf during the Early Devonian. Fully marine conditions were subsequently re-established in the Middle Devonian to early Frasnian and persisted into the early Late Carboniferous.A widespread uplift in the latest Carboniferous turned the entire area into a continental regime before the onset of a new marine cycle during the late Early Permian. With the exception of the northern zone (Talesh Range, Aghdarband), the Palaeozoic of Iran is characterized by continental to shallow marine deposits showing that enormous portions of the northern margin of this sector of Gondwana have been subducted during the convergence of the Turan and Iran Plates and the elimination of the Palaeotethys during the Late Triassic.
Neptunian sills at Rocca Busambra, a fragment of the Trapanese/Saccense Domain in western Sicily, host the most abundant ammonite and gastropod fauna which has ever been recorded from the Jurassic of the western Tethys. The fauna is dominated by parautochthonous organisms which were swept into the sills by gentle transport. Ammonites are characterized by perfect preservation and small size, a feature which is due to the predominance of microconchs but also of stunting. The most complete sill is 0.7 m thick and could be separated into 17 levels which range in age from the early Toarcian into the late Kimmeridgian, thus representing the most extreme case of palaeontologically and depositionally documented stratigraphic condensation in Earth history. The unique feature of the Rocca Busambra sills is due to the interaction of three processes: extreme stratigraphic condensation on the sea floor, weak tectonic fracturing of the host rock and repeated reopening on top of already existing sills. Contrasting percentages of gastropods in individual levels reflect sea-level oscillations which correspond to long known low- and highstands during the Jurassic of the western Tethys. Comparisons with other ammonite-bearing sill faunas reveal several similarities, but represent only short-timed phases of tectonic pulses and deposition.
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During the late Carnian a great number of carbonate mud mounds were constructed along the submerget northwestern margin of the Yangzi Platform in Sichuan, in the transition zone between the Songpan Garze Trough in the west and the Chuan Dian Shelf in the east. Individual mounds are up to 80 m thick and have base diameters of up to several hundred meters. Thickness ratios between mound and intermound deposits are about 5:1 with mound slopes not exceeding 15 stopni. The bulk of the rock volume consists of a microsparitic matrix which due to its peloidal structure and common laminated crusts is probably a cyanobacterial precipitate. Siliceous sponges contributed to mound stabilization but did not form a rigid framework. Several other invertebrate groups (mainly crinoids) inhabitated the mound surfaces and were transported into adjacent depressions. Stromatactoid cavities, which are so characteristic for Palaeozoic mud mounds, are extremely rare. Generally they are completely occluded with late diagenetic blocky spar; only a few cavities are lined with an early marine RFC cement. The latter is distinguished by relatively heavy delta^18 O signatures of -3,4 promile PDB which contrast with the isotopic composition of the burial cements displaying mean values of -9,7promile delta^18 O PDB. [87^Sr/86^Sr] ratios of early cements, matrix and non-luminescent brachiopod shells fit well into the curve of the isotopic evolution of the Phanerozoic seawater.
W dniach od 1 czerwca do 31 października 2000 roku odbędzie się w Hanowerze najbliższa światowa wystawa EXPO 2000 pod hasłem "Człowiek, Natura, Technika". Oczekiwanych jest 170 wystawców (krajów) i 40 milionów gości, czyli 300 tysięcy zwiedzających dziennie.
Celem pracy jest przedstawienie zróżnicowania rozmieszczenia bazy noclegowej, która zaraz obok dostępności transportowej odgrywa kluczową rolę w kształtowaniu wielkości ruchu turystycznego. Celem pobocznym jest przestawienie największych pod względem wielkości międzynarodowych holdingów zrzeszających obiekty noclegowe oraz prowadzonej przez nich polityki w zakresie świadczonych usług oraz ich dynamiki rozwoju. Ponadto, autorzy podjęli próbę analizy zmian wielkości bazy noclegowej UE w ujęciu krajowym. Następnie podjęto próbę oceny jakości świadczonych usług w relacji do ich ceny na podstawie badań przeprowadzonych za pomocą danych dostępnych na stronie www.hotel.info. Całość pracy kończą wnioski, w których autorzy podejmują próbę określenia zależności pomiędzy standardem oferowanych usług a subiektywną oceną klientów z nich korzystających.
EN
The main aim of this paper is to present the diversity of accommodation arrangement which next to transport accessibility has a key role in shaping the level of tourist traffic. The secondary aim of paper is to present the biggest holdings of international accommodations and policies pursued by them in terms of provided services with their rate of growth. Additionally, authors attempted to analyze changes in the availability of accommodation in EU countries. Then they attempt to compare the quality of provided services in relation to prices according to research conducted by the data available on the website www.hotel.info. Work is ended by conclusions with attempt to determine the relation between the quality level of services and subjective marks given by customers.
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Strongly mineralized lithologies were found in 4 different depositional settings along the northern margin of the Hoggar Massif in southern Algeria: (1) Pleistocene fluvial terraces, (2) pebble-filled erosional furrows in marine Silurian and Upper Devonian shales, (3) sedimentary dykes in Givetian mud buildups and (4) tectonic fault fissures and cracks in Upper Devonian shales. In spite of the contrasting sedimentary environment, all these rocks display very similar properties and are considered as contemporaneous. They are characterized by high porosities, intense Fe-mineralization and a great variety of accompanying, secondary minerals formed in a subrecent continental regime under pluvial to arid conditions. The dykes, faults and cracks are direct evidence of tensional stress during the early and middle Pleistocene which has not been observed so far. The complex sedimentary and diagenetic history of conglomerates, breccias, sandstones, ferricretes, calcretes and claystones in these settings was analyzed using SEM, EDX-microprobe, XRD, transmitted and reflected light petrography and is documented in hitherto unknown details.
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The mountains N of Kerman in southeastern Iran are a key region for Devonian/Lower Carboniferous stratigraphy of a still poorly known segment on the northern margin of Gondwana and display a great diversity of neritic depositional environments. The hitherto applied subdivision into lithostratigraphic formations has been calibrated by means of conodonts and brachiopods allowing good correlations of 36 sections, the majority of them ranging from the top of the Cambrian or the Silurian into the Lower Permian. Upper Cambrian sandstones or Silurian carbonates are unconformably overlain by red siliciclastics of uncertain Early to early Middle Devonian age (Padeha Formation) which in turn pass into skeletal limestones (upper Middle Devonian to Tournaisian Bahram and Sardar Formations). The latter are erosionally capped by Permian platform carbonates (Jamal Formation). Facies patterns during 5 intervals from the Silurian into the Tournaisian show evolution from a carbonate platform and siliciclastic shelf during the Silurian and the Early Devonian into shallow open marine embayments during the late Middle and Late Devonian, and a carbonate platform during the Early Carboniferous. Sharp boundaries between Upper Devonian facies belts appear controlled by synsedimentary epeirogenic movements which may have been active since the Early Palaeozoic.
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