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1.
Exposures of the Menuha Formation (Santonian–Early Campanian, Mount Scopus Group) in the Makhtesh Ramon region of the southern Negev have produced numerous chondrichthyan teeth. The isolated teeth represent at least ten different species: Cretalamna appendiculata, Cretoxyrhina mantelli, Squalicorax falcatus?, S. kaupi, Scapanorhynchus rapax, S. raphiodon?, Carcharias samhammeri, Carcharias cf. C. holmdelensis?, and two other fish (Hadrodus priscus and a pycnodont). This assemblage has important implications for Late Cretaceous chondrichthyan palaeobiogeography. The majority of teeth were contained within a glauconite-rich, yellow-brown, soft chalk that included oysters (Pycnodonte vesicularis?), trace fossils (Planolites, Thalassinoides, and Chondrites), phosphatic peloids, and foraminiferans (globigerinids). The teeth were collected mainly through surface-sampling and sieving. The Menuha Formation probably represents a temperate to subtropical, shallow, open-shelf environment deposited during the formation of the Ramon anticline. Reworked conglomeratic chalks in the western section represent marginal facies derived from this structural uplift. With little to no published material describing the chondrichthyan fauna of the Menuha Formation, these data improve interpretations of its palaeoenvironment. Interpretation of the palaeoenvironment of the formation is important for understanding the larger stratigraphic/tectonic framework of the Ramon monocline region of southern Israel.  相似文献   

2.
A map shows intrinsic vulnerability to pollution of the Chrzanów karst-fissured aquifer (273 km2) in the southern part of Poland. This aquifer is intensively drained by numerous intakes and Zn-Pb ore mines. A DRASTIC-type parametric system was applied for groundwater vulnerability evaluation. Vulnerability assessment is based on six factors (depth to groundwater table, lithology of the unsaturated zone, net recharge, hydraulic conductivity of the aquifer, groundwater flow velocity, aquifer thickness). For the final vulnerability map construction at the scale of 1:50,000, a combination of the aquifer simulation model (using MODFLOW) and a geographical information system was applied. Maps of the net recharge, hydraulic conductivity of the aquifer and groundwater flow velocity were derived by aquifer modelling. Based on the vulnerability index (21-182), six relative vulnerability classes were selected. Reliability of the map has been verified.  相似文献   

3.
The porphyry copper-molybdenum deposit at Myszkow, south-central Poland, lies in the Cracow-Silesian orogenic belt, in the vicinity of a Paleozoic boundary between two tectonic plates. The deposit is hosted in a complex that includes early Paleozoic metasedimentary rocks intruded in the late Paleozoic by a predominantly granodioritic pluton. This deposit exhibits many features that are typical of porphyry copper deposits associated with calc-alkaline intrusive rocks, including ore- and alteration-mineral suites, zoning of ore and alteration minerals, fluid-inclusion chemistry, tectonic setting, and structural style of veining. Unusual features of the Myszkow deposit include high concentrations of tungsten and the late Paleozoic (Variscan) age.  相似文献   

4.
The sedimentary succession exposed in the Gorzów Wielkopolski area includes Eemian Interglacial (MIS 5e) or Early Weichselian (MIS 5d–e) deposits. The sedimentary sequence has been the object of intense interdisciplinary study, which has resulted in the identification of at least two palaeolake horizons. Both yielded fossil remains of large mammals, alongside pollen and plant macrofossils. All these proxies have been used to reconstruct the environmental conditions prevailing at the time of deposition, as well as to define the geological context and the biochronological position of the fauna. Optically stimulated luminescence dating of the glaciofluvial layers of the GS3 succession to 123.6 ± 10.1 (below the lower palaeolake) and 72.0 ± 5.2 ka (above the upper palaeolake) indicate that the site formed during the Middle–Late Pleistocene (MIS 6 – MIS 5). Radiocarbon-dating of the lacustrine organic matter revealed a tight cluster of Middle Pleniglacial Period (MIS 3) ages in the range of ~41–32 ka cal bp (Hengelo – Denekamp Interstadials). Holocene organic layers have also been found, with 14C ages within a range of 4330–4280 cal bp (Neolithic). Pollen and plant macrofossil records, together with sedimentological and geochemical data, confirm the dating to the Eemian Interglacial.  相似文献   

5.
An abundant and diverse fauna of thoracican cirripedes is described on the basis of over 3000 isolated valves collected from a single lens of material representing in the order of a few thousand years of Campanian time (c. 80 Ma), from sediment formed on and close to a rocky shoreline at Ivö Klack in southern Sweden. At least twenty-eight species are present in the fauna, belonging to scalpelliform and basal sessile taxa. Two families (Myolepadidae and Titanolepadidae) and four genera are new (Myolepas, Bosquetlepas, Levelepas and Ivoelepas), as are seven species (Titanolepas spinifer, Levelepas roeperi, Ivoelepas nielseni, Arcoscalpellum scaniensis, Pollicipes vansyoci and P. (?) striatum). The palaeoecology is discussed with reference to extant cirripede faunas from rocky coastal environments. It is concluded that, although many taxa lived subtidally, the pollicipedids and pollicipedid-like forms (Capitulum, Pollicipes and Myolepas, respectively) lived in the intertidal zone, attached to rocks in a high-energy environment. Pachydiadema, a large basal balanomorph species, was adapted to living attached to boulders in the intertidal zone. The remarkable diversity significantly exceeds that of any known fossil thoracican assemblage, and is unknown in similar habitats at the present day, possibly challenging Darwin's famous quip that we currently live in the ‘Age of Barnacles’.  相似文献   

6.
7.
Summary Minute inclusions of phlogopite and a chlorite-vermiculite intergrade mineral occur in the vesuvianite from rodingite at Przemiów (Lower Silesia). The same inclusions were found in its blackwall, i.e. outer metasomatic zone formed at the expense of adjacent ultrabasic rock. These findings demonstrate that potassium was released from the rodingite protolith during the Ca-metasomatism that accompanied low-temperature serpentinization and was consumed by phlogopite formed in the rodingite blackwall. Fresh phlogopite persists as small inclusions in vesuvianite. The abundant phlogopite-derived intergrade chlorite-vermiculite in the blackwall documents the potassium-rich composition of the protolith of the rodingite, though its primary chemistry is highly modified during metasomatic processes. The rodingite blackwall can be useful as tracer of the metamorphic and tectonic episodes obscured during complex geological evolution of the ophiolite.
Schichtsilikate von Rodingit- Blackwalls aus Przemiów (Niederschlesien, Polen): Mineralogische Dokumentation metasomatischer Prozesse während der Serpentinisierung und der Rekristallisation von Serpentinit
Zusammenfassung Winzige Einschlüsse von Phlogopit und einem K-führenden Chlorit-Vermiculit Mineral wurden in Vesuvian aus Rodingiten von Przemiów (Niederschlesien) gefunden. Dieselben Minerale treten in der sogenannten Blackwall, i.e. der äußeren metasomatischen Zone, die sich auf Kosten der angrenzenden Ultrabasite gebildet hat, auf. Diese Ergebnisse zeigen, daß Kalium aus dem Rodingit-Protolith während der Ca-Metasomatose, die die Niedrig-Temperatur 5erpentinisierung begleitete, freigesetzt wurde und von Phlogopit, der sich in der Blackwall bildete, konsumiert wurde. Frische kleine Phlogopite sind als Einschlüsse in Vesuvian erhalten geblieben. Das aus dem Phlogopit entstandene verbreitete Chlorit-Vermiculit Mineral belegt eine Kaliumreiche Zusammensetzung des Rodingit-Protoliths, obwohl die primäre Chemie durch metasomatische Prozesse stark verändert wurde.


With 7 Figures  相似文献   

8.
《Gondwana Research》2009,15(4):675-685
Chemical Th–U–total Pb (CHIME) dating of monazite by electron probe microanalyzer (EPMA) and proton microprobe (PIXE) was carried out on felsic granulites from Stary Gierałtów, Poland, which represent part of the Orlica-Śnieżnik Dome in the NE Bohemian Massif. Analyzed monazite is characterized by mosaic zoning rather than simple core-to-rim growth, and strontium contents of up to 750ppm. An isochron age of 347 ± 13Ma represents timing of amphibolite-facies metamorphism, in agreement with previously published estimates.  相似文献   

9.
To constrain the age of Australian opal formation, we have undertaken a paleomagnetic study of oxidised ironstone ‘nuts’ from Yowah, Queensland. Following standard methods, we have calculated a mean direction of declination D = 191.4°, inclination I = 61.7° (α95 = 4.0°), indicating a paleomagnetic pole position at latitude λp = 71.3°S, longitude ?p = 119.4°E (A95 = 5.3°). The direction comprises both normal and reverse polarities that fail a reversal test most probably owing to contamination by small recent/present-day components. The mean direction should not be significantly affected. A chi-square comparison with paleomagnetic poles for dated Cenozoic rocks in eastern Australia, poles derived from the Global Moving Hotspot Reference Frame and the Cenozoic pole path for North America, appropriately transferred to Australian coordinates, yields a mean age estimate of 35 ± 7 Ma, i.e. late Eocene to early Oligocene. This is interpreted as the age of the ironstone formation, which places a maximum age for the formation of precious Yowah opal. This result confirms and tightens the age for the nearby Canaway weathered profile.  相似文献   

10.
As the boundary thrust between India and Asia in southern Tibet, the Zhongba–Gyangze Thrust (ZGT) emplaced the Yarlung Zangbo Suture Zone (YZSZ) units in the hanging wall southward onto Tethyan Himalaya sequences (THS) of the northern Indian continental margin in the footwall. Detailed field investigation, electron backscatter diffraction (EBSD) analysis, detrital zircon U–Pb geochronology and 40Ar–39Ar thermochronology were conducted to understand the evolution of the ZGT in Sangsang area, central southern Tibet. The shear zone of ZGT is located within the sedimentary-matrix mélange of YZSZ that is mainly composed of matrix of blueschist with meta pelagic–hemipelagic siliceous and siliciclastic rocks and blocks of basalt, limestone and sandstone. Penetrative F1 foliation and kink band structure were recorded within the matrix both on outcrop and under microscope. Strong lattice preferred orientation (LPO) fabric initiated by the low-temperature (350−450 °C) (010)[001] slip system was detected by EBSD in the sodic amphiboles of the blueschist. The 40Ar–39Ar ages of the phengites from blueschist and sericites from the phyllite in the shear zone indicate that the activity of ZGT occurred between 71 and 60 Ma. In the THS, a newly documented younger unit preserving detrital zircons from the southern Asian margin lies above the Triassic–Cretaceous sequences that carries only detrital zircons from the Indian continent. This unit is dated to be ~ 61 Ma by the detrital zircon ages, similar to the Sangdanlin Formation and representing the Yarlung Zangbo Foreland Basin (YZFB) system. The ZGT had probably been active due to the initial India–Asia collision and acted as the frontal thrust controlling the development of YZFB.  相似文献   

11.
The study was carried out on the Sulejów dam reservoir (Central Poland). Water and sediment samples were collected between February and October 2006. Sulfur compounds in the sediment were chemically extracted and subjected to isotopic analysis.Large variability of SO42− concentration in the water column (from 10.3 to 36.2 mg/dm3) and the isotopic composition of sulfur (δ34S from 2.1 to 5.4‰) was observed. The main identified sources of SO42− were watercourses, surface runoff, and phosphorus fertilizers.Both oxidized sulfur species (SO42−) and its reduced forms were found in sediments. Particular sulfur forms were characterized by large variations in both, concentrations and the isotopic composition of sulfur. SO42− in the sediment and in the water column had different genesis. Bacterial oxidation of organic sulfur and its binding in SO42− were observed in the sediment. Under reducing conditions, oxidized and organic sulfur is converted to H2S which reacted with Fe or other metallic ions leading to metal sulfide precipitation. Monosulfides were shown to have a very low concentration, ranging up to 0.07 mg/g of sediment. The transformation of elemental sulfur from sulfides through their chemical oxidation occurred in the sediment.  相似文献   

12.
13.
The fossil dendrobranchiate shrimp Macropenaeus was originally described from the Upper Cretaceous (Cenomanian) limestones of Hadjoula, northwest Lebanon. A new species, M. sidiaichensis sp. nov., was recovered from the Sidi Aïch Formation in the Northern Chotts Range, southern Tunisia. The Barremian occurrence of the genus in Tunisia suggests that Macropenaeus most likely originated in northern Africa and then migrated to Arabia in the Cenomanian. The association of the fossil shrimp with conchostracans, plant fragments, and fish indicates the interaction of freshwater and marine conditions that characterized the northern African margin as part of widespread coastal complex, paralic environments during the Barremian.  相似文献   

14.
This paper provides the first palynological data from four Upper Cretaceous localities from the Islands of Hvar and Šćedro (southern Croatia), in the central part of the Adriatic Carbonate Platform. Studied material represents palynomorphs produced by coastal vegetation and transported to the shallow marine platform areas. Determined vegetation includes diverse hygrophilous, understory vegetation, range of evergreen needle trees attributable to Pinaceae and Podocarpaceae, as well as Araucarian conifers; ginkgo, cycads and/or bennettites. Flowering plants were likely represented by herbaceous forms. The palynoflora is generally indicative of a temperate, warm and humid climate. The occurrence of the Normapolles group with the presence of Plicapollis sp. and Pseudoculopollis sp. point to Turonian or probable Turonian–Coniacian age, and represent the southernmost record of occurrence within the Normapolles palynological province. Dominance of angiosperms and low abundance of ferns suggests an early-Late Cretaceous age. These findings are supported by the micropaleontological analyses and previously determined age of the sauropod dinosaur footprints described on the Island of Hvar. Based on the paleobotanical and palynological data, the dinosaur diet probably included araucarian conifers, ginkgo and angiosperms, and ferns to a lesser extent.  相似文献   

15.
The population of Saynoceras verrucosum (d’Orbigny) from the Polish basin (W?wa? section, central Poland) shows no significant intraspecific variability. Dimorphism has not been found in this population. Statistical analyses of material from the shallow epicratonic Polish basin and the relatively deep Vocontian basin (southeastern France) indicated two populations. Forms from the Polish basin are somewhat more inflated and smaller than forms from the Vocontian basin.  相似文献   

16.
Li  Yalin  He  Haiyang  Wang  Chengshan  Wei  Yushuai  Chen  Xi  He  Juan  Ning  Zijie  Zhou  Aorigele 《International Journal of Earth Sciences》2017,106(4):1289-1310
International Journal of Earth Sciences - The lack of Early Cretaceous magmatic records with high-quality geochemical data in the southern Qiangtang subterrane has inhibited a complete...  相似文献   

17.
18.
The Cenomanian–Turonian ammonite biostratigraphical framework for the southern Tethys margin (North Africa, Middle East and the Arabian Peninsula) is becoming better understood. A first attempt at a synthetic range chart is presented, with 85 taxa and precise correlations for ammonites along a west–east transect from Morocco to Oman, inclusive of the Trans-Saharan Seaway as far south as northern Nigeria. On the basis of a critical review of ammonite taxonomy, 13 bioevents can be identified in the interval from the Late Cenomanian to the Early Turonian (c. 3.5 myr) with each bioevent corresponding to a time interval of approximately 270,000 years, on average. They are consistent throughout several regions along the southern Tethys margin, though some gaps remain, at least at the stage boundary. These bioevents are correlated with the zonation defined for the stratotype (GSSP) of the base of the Turonian in the Western Interior (USA). The paleobiogeographic distribution of ammonites reveals some endemism but the predominant picture is that of a homogeneous fauna throughout the area, even though distinct Boreal and Western Tethys (Atlantic domain) marine influences are evident. An interpretation of the evolution of conch morphology and ornamentation through the zones of the Late Cenomanian–Early Turonian is proposed.  相似文献   

19.
20.
A new fossil species,Anthoscytina macula sp.nov.,of the family Procercopidae is described from the Early Cretaceous Yixian Formation in Huangbanjigou,Chaomidian Village,Beipiao City,Liaoning Province,China.A key to the species of the genus Anthoscytina Hong,1983 is provided.The diagnosis of the genus is revised.  相似文献   

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