Wyniki wyszukiwania - BazTech

1

Conodonts and foraminifera from the "Raibl Beds" (Carnian) of the Karavanke Mountains, Slovenia : stratigraphical and palaeobiological implications

Kolar-Jurkovšek T., Jurkovšek B., Gaździcki A.

Geological Quarterly

|

2005

|

Vol. 49, No. 4

429-438

EN

Themicropalaeontology of the "Raibl Beds" of the Košuta Nappe in the western KaravankeMts., Slovenia, is described. The presence of the conodont apparatus of Nicoraella? budaensis Kozur and Mock is demonstrated and together with other fossils it confirms a Carnian age. A comparison of the Nicoraella skeletal apparatus with two other Triassic apparatuses is made. The benthic foraminifera Aulotortus sinuosus, A. tumidus, Prorakusia salaji, Pilamminella kuthani and Endothyra kuepperi are recognized. Their stratigraphical range corresponds to the foraminiferal Pilamminella kuthani Interval-Zone. Altogether the palaeontological content of an 85 m-thick section in the upper part of the "Raibl Beds" below Mt. Jepca is described. The diverse fossil content of this section contributes to the intercalibration of Upper Triassic conodont, foraminifer and dasyclad zonations.

2

Late Triassic charophytes around the bone-bearing bed at Krasiejów (SW Poland) : palaeoecological and environmental remarks

Zatoń M., Piechota A., Sienkiewicz E.

Acta Geologica Polonica

|

2005

|

Vol. 55, no. 3

283-293

EN

Thousands of Late Carnian (Late Triassic) charophyte gyrogonites belonging to four species [Stellatochara germanica KOZUR & REINHARDT, Stomochara starozhilovae (KISIELEVSKY), Stenochara kisielevskyi BILAN and Porochara triassica (SAIDAKOVSKY)] occur in the beds around the vertebrate-bearing level at Krasiejów, SW Poland. The abundant and wellpreserved gyrogonites generally attest to fossilization in situ. Information about the habitat of recent charophytes is useful for reconstruction of their past environments. The factors limiting the habitat of modern charophytes suggests that these algae, and other micro- and macrofauna sedimented within the bone-bearing bed, lived in a shallow, freshwater environment (probably lacustrine). Above the bone bed, there is a rapid drop in gyrogonite abundance. This could have been caused by changes in environmental conditions: increase in salinity, or increase in water energy.The preliminary mineralogical data suggest arid to semi-arid climate.

3

Upper Triassic (Carnian) mud mounds from northern Sichuan (China)

Wendt J.

Acta Geologica Polonica

|

2001

|

Vol. 51, nr 1

1-13

EN

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.

4

Późnotriasowe cmentarzysko kręgowców lądowych w Krasiejowie na Śląsku Opolskim

Dzik J., Sulej T., Kaim A., Niedźwiedzki R.

Przegląd Geologiczny

|

2000

|

Vol. 48, nr 3

226-235

PL

W obrębie serii ilastej „retyku” w Krasiejowie koło Ozimka zidentyfikowany został poziom, zawierający liczne czaszki i fragmenty szkieletów kontynentalnych czworonogów (głównie ziemnowodnych). Dominują wielkie labiryntodonty Metoposaurus, tekodonty (fitozaury) Paleorhinus, pancerne roślinożerne tekodonty z rodziny Aetosauridae, drapieżne labiryntodonty z nadrodziny Capitosauroidea, oraz znane tylko z pojedynczych kości najpierwotniejsze dinozaury. Bardzo rzadkie są zęby ryb dwudysznych Ceratodus i łuski ryb ganoidowych. Szczątkom kręgowców towarzyszą liczne małże słodkowodne z grupy unionidów, a w próbkach mikropaleontologicznych w wielkiej obfitości występują ramienice, wskazujące na słodkowodne środowisko sedymentacji. Jest to typowy zespół fauny Paleorhinus, o niemal globalnym rozprzestrzenieniu ograniczonym czasowo do środkowej i późnej części karniku. Paleontologiczne datowanie warstw zlokalizowanych nad ostatnimi wystąpieniami gipsu oznacza konieczność rewizji stratygrafii i korelacji wiekowej tej części polskiego triasu.

EN

A new Paleorhinus/auna has been discovered in a grey claystone corresponding to the subsurface Drawno beds, which are exposed in a cement plant claypit at Krasiejów near Opole in southern Poland. The vertebrate assemblage of perfectly preserved skeletons, isolated skulls, and postcranial remains is dominated with labyrinthodonts Metoposaurus di&gnosticus, the phytosaur Paleorhinus sp. being the second in number. Aetosaurs are represented by an incomplete skull, scuta and fragmentary bones. One sacral bone most probably representing an early dinosaur related to Staurikosaurus or Chindesaurus and two incomplete maxilla with teeth showing serration parallel to the cusp have also been found. The Krasiejów assemblage includes also dipnoans Ceratodus, undetermined fish scales and teeth, numerous unionid bivalves, very abundant characean gyrogonites, and ostracods. The Paleorhinus species is relatively short-snouted and may represent an earlier stage in the evolution of the lineage than fhe populations from Blasensandstein in Franconia and other known Yz\eor\ńm\s faunas. This is consistent with the presence q/Metoposaurus diagnosticus, the species originally described from the Schilfsandstein, located below the Blasensandstein. An equivalent ofSchilfsandstein is known in boreholes drilled nearby the locality and the bone-bearing horizon is about 80 m above its top, and about 20 m above the last occurrence of gypsum in the section. Lehrberg Schichten in Germany seem thus to be its lateral equivalents, both presumably representing the final event in the middle to late Carnian eustatic cycle. The Paleorhinus/a""a was apparently persistent in the area, as an incomplete skeleton has been found about 8 m below the mostfossiliferous horizon, in a calcareous intercalation within red clays comparable with the German Rote Wand.