郧县人遗址石核的研究

在郧县人遗址中发现的石核占整个遗址石制品总数的26%。虽然数量仅77件,但从石核上可以看出打片以锤击法为主,采用硬锤直接打击。其利用率不高。石核的打片长度基本上只占该台面周长的一半以下,多在台面的一个边打片,剥片面上的石片疤多为单层,有些打下一块石片后就不再继续打片了。     

Late Triassic sedimentary evolution of Slovenian Basin (eastern Southern Alps): description and correlation of the Slatnik Formation

Successions of the Slovenian Basin structurally belong to the easternmost Southern Alps. During the Late Triassic, they were part of the Adriatic continental margin. Norian–Rhaetian successions of the Slovenian Basin are characterized mainly by dolomite of the Bača Dolomite Formation. However, in the northern part of the basin, Late Triassic limestone is preserved above Bača Dolomite Formation and is formalized as the Slatnik Formation. It is composed of hemipelagic limestone alternating with resedimented limestones. The succession documents an upward progradation of the slope environment composed of three high-frequency cycles. Most prominent progradation is referred to the second, i.e., Early Rhaetian cycle. The Slatnik Formation ends with thin-bedded hemipelagic limestone that records the end-Triassic productivity crisis, or rapid sea-level fall. The overlying resedimented limestones of the Early Jurassic Krikov Formation, document the recovery of production and shedding from the adjacent carbonate platform.     

Spatial and temporal development of siliceous basin and shallow-water carbonate sedimentation in Oxfordian Northern Calcareous Alps

The Late Jurassic succession of Mount Rettenstein (central Northern Calcareous Alps, Austria) is unique in comparison to all other sections known in the Northern Calcareous Alps because it provides the oldest coexistence of radiolarite basin sedimentation with contemporaneous shallow-water carbonate intercalations. An up to 3.5-m-thick debris flow made up of shallow-water carbonate detritus with a radiolaritic matrix is overlain by thin (calcareous) radiolarite, followed by several hundreds of meters of shallow-water carbonates of the Plassen Formation. Benthic foraminifers (Labyrinthia mirabilis Weynschenk and Alveosepta aff. jaccardi) and the radiolarian associations indicate a depositional age of both the debris flow and the basal Plassen Formation around the boundary of Middle/Late Oxfordian resp. in the Late Oxfordian. This is as yet the first unambiguous evidence of Oxfordian shallow-water sedimentation in the Northern Calcareous Alps. This early neritic stage with the settlement of ooid bars and coral-stromatoporoid-reefs, evidenced by the debris flow resediments in siliceous basin sedimentation, is followed by the definite, rapid progradation of the actual Late Oxfordian/Kimmeridgian–Berriasian Plassen Carbonate Platform with its steep slope configuration. Assumably, this evolution was steered by a mixture of both global environmental and regional tectonic constraints.     

Silurian to Mississippian series of the eastern Catalan Pyrenees (Spain), updated by conodonts, foraminifers and algae

Stratigraphic sections and microfossils samples from the upper part of the “Graptolitic Shales-Orthoceras Limestones” and from the Camprodon Formation lying in the area of Camprodon, eastern Pyrenees, Spain, have been studied. Some beds at the top of the “Graptolitic Shales-Orthoceras Limestones” correspond to the Torres Member of the Rueda Formation, and conodont faunas, indicating a Lochkovian age, are described. The Camprodon Fm. is interpreted to be turbidites deposited in deep sea fans, although slope deposits prevail in the eastern sections. One reworked carbonate clast from the Camprodon Fm. provided a valuable early Ludlow conodont fauna, from the Kockelella crassa Zone, reported for the first time in the Iberian Peninsula. Late Devonian conodonts and late Visean (Asbian-Brigantian) foraminifers and algae were also obtained from reworked limestone clasts, and latest Visean or Serpukhovian foraminifers from the sandstone matrix in the Camprodon Fm. The studied microfossils suggest a late Mississippian age for the Camprodon Fm. instead of the previously assigned late Silurian-Lochkovian age. This age must be considered when discussing the distribution of the Culm Facies in the Pyrenees and the significance of the contact between the Camprodon Fm. and the underlying “Graptolitic Shales”.     

一个重要的蒙古二叠纪牙形刺种

在蒙古南部Lugiingol剖面卢金格尔(Lugiingol)组下部发现牙形刺Mesogondolell aidahoensis,该地层应归入下二叠统空谷阶,而不是像以前那样归入上二叠统。     

Conodont biostratigraphy of the Upper Devonian-Lower Carboniferous Shahmirzad section, central Alborz, Iran

The conodont fauna from the Devonian-Carboniferous Shahmirzad section, located in the Central Alborz Mountains (North Iran), have been studied mainly for biostratigraphic purposes. Some levels were barren of conodonts, whereas others yielded a not very abundant, but quite differentiated fauna. No conodonts have been found from the mainly terrigenous and shaly Geirud Formation, whereas representative of genera Bispathodus, Clydagnathus, Gnathodus, Hindeodus, Mehlina, Polygnathus, Protognathodus, Pseudopolygnathus and Siphonodella have been collected from the mainly calcareous overlaying Mobarak Formation. The fauna allowed to discriminate five biointervals, from the sulcata Zone to a “Lower typicus - anchoralis-latus interval” in the central part of the section, while the lower and upper parts cannot be zoned on the basis of conodonts. This paper is the first report on lowermost Carboniferous conodonts from the Mobarak Formation in central Alborz.     

Birth and early evolution of a Jurassic escarpment: Monte Kumeta Western Sicily

Summary The accurate reconstruction of the facies architecture in the Jurassic succession of Monte Kumeta, coupled with a detailed biostratigraphy, allow to define dynamics and genetic factors controlling the conversion of a Bahamian-type carbonate platform to a pelagic escarpment. A change from tidalites to oolites i.e. from the restricted, interior lagoon to a more open-marine sandy depositional environment, records the establishment of a basin south of the Monte Kumeta sector in late Hettangian-Sinemurian times. The oolitic limestones are overlain by earliest Carixian bioclastic grainstones and packstones with micritized grains and by wackestones with radiolarians and sponge spicules, organized in thin sand prisms. The decrease of carbonate productivity indicated by these sediments records the dissection of the platform and the subsequent isolation of a submarine topographic high in the Monte Kumeta sector. Though based only on indirect evidence, it is suggested that a tectonically controlled scarp must have existed between the Monte Kumeta “high” and the basin. Progressive northward retreat of this scarp resulted in the conversion of a shallow platform sector into a gradually steepening slope, along which the distribution of sediments was controlled by repeated tectonic and gravity-induced modifications of the topography of the substrate. Vertical and lateral changes and geometrical relationships of the recognized lithofacies suggest that they were deposited on a stepped surface brought about mainly by, repeatedly reactivated basin ward dipping normal faults. This scenario is clearly reflected by the relationship of platform strata and the overlying encrinites of Carixian/Domerian age. The encrinite bodies show again a prismatic geometry, becoming thicker towards the south and filling the first generation of neptunian dykes. The top of the encrinites is marked by a peculiar jagged dissolution surface with dm-scale pinnacles capped by a thick ferromanganese crust. The formation of this peculiar surface could have been controlled by complex changes in water chemistry probably related to the Early Toarcian anoxic event. The crust itself is dissected by faults of decimetres to metres of throw, sometimes organized into small-scale positive flower structures. In the hollows/depressions of this highly articulated substrate pelagic sediments of Bajocian to Oxfordian age were deposited. They display a clearly onlapping relationship to the encrinites and to the carbonate platform beds. Their thickness rarely exceeds 4 to 5 meters and they are present also as neptunian dykes filling a dense network of fissures. During Late Callovian and Oxfordian times synsedimentary tectonics has intensified resulting in an increase of the inclination of the slope. This led to more and more abundant, gravitationally controlled deformations (slumping and sliding) of semi-lithified and unlithified sediments along the Monte Kumeta escarpment.     

Traces of microboring organisms in Palaeozoic conodont elements

Conodont elements from Palaeozoic strata (Ordovician, Devonian and Carboniferous) contain abundant evidence for presumed post-mortem colonisation by endolithic organisms. It is possible to distinguish several morphotypes of microcavities in conodont apatite, which show some morphological similarities to microborings in calcareous substrates. Some of them are believed to be produced by microendoliths, some others are yet unknown from calcareous substrates. The present report deals with the various kinds of microendolithic traces in conodont apatite. The significance of microborings in conodont elements is discussed.     

The assessment of posture control in the elderly using the displacement of the center of pressure after forward platform translation

We investigated the change of the center of pressure (COP) after forward platform translations in healthy subjects. These studies were performed on 26 normal young subjects and 20 healthy elderly subjects, who had a normal neurologic examination. Subjects stood barefoot on a three dimensional force plate on the platform, with feet parallel. The duration of the forward platform translations was 0.15 s, and the displacements were 3.75, 7.5, 10, 15, 20, and 30 mm. Six trials were carried out at random. The COP data were recorded for 35 s during standing, and were analyzed for 5 s after translation. With the platform translation displacements from 3.75 to 15 mm, displacement of the COP showed a tendency to increase in all subjects. Whereas with the stimuli between 20 and 30 mm, the results were more varied. The elderly group showed significantly (p<0.05) larger sway than the young group. These results indicate that the individual ability of posture control may be assessed by means of measuring the sway of the center of gravity after platform translation. Electromyography was carried out simultaneously, it showed that elderly people contrary to young subjects used proximal biceps femoris and distal foot muscles at an early stage of the platform translation (p<0.05), suggesting lack of ankle stability with aging.     

The Madenli (Central Taurides) Upper Cretaceous platform carbonate succession: Benthic foraminiferal biostratigraphy and platform evolution

The Upper Cretaceous succession in the Madenli area (western Central Taurides, Southern Turkey) consists of platform carbonate rocks deposited in entirely peritidal environments, which are sensitive to sea level changes driven by global eustasy, but also strongly affected by local and regional tectonics. It includes economically important bauxite deposits. Previous works suggest different ages for bauxite formation ranging from the Albian to the Santonian. Benthic foraminiferal biostratigraphy and facies analysis of the Madenli and Doğankuzu outcrop sections allow for a more precise dating of the platform emersion periods. The footwall limestones of the bauxite deposits consist of well-bedded limestones (Unit-1), which contain a benthic foraminiferal assemblage (BFA) including mainly Biconcava bentori and Pastrikella biplana, Chrysalidina gradata (BFA I), assigned to the middle-upper Cenomanian. In the Madenli section, the first bauxite deposit occurs in the upper part of Unit-1 as a layer interbedded with pinkish sparitic and dolomitic beds (subunit-1a) deposited in supratidal environment. Subunit-1a is stratigraphically equivalent to the Doğankuzu and Mortaş bauxite deposits considered as karst-related, unconformity-type deposits. The hanging-wall limestones of the bauxite are represented by the massive limestones (Unit-2) starting locally with either the upper Cenomanian characterized mainly by the presence of Pseudolituonella reicheli or upper Campanian comprising mainly Murciella cuvillieri and Moncharmontia apenninica (BFA II). There is no field evidence of a discontinuity surface at the contact between the lower part of Unit-2, including BFA I, and the upper part of Unit-2, including BFA II. This contact is defined as a paraconformity indicating a stratigraphic gap from the Turonian to the early Campanian. The top of Unit-2 is truncated by another discontinuity surface associated with a minor bauxite deposit. The overlying Unit-3 is characterized by well-bedded, rudist-bearing limestones topped by laminated and dolomitized limestones organized in shallowing upward cycles. It is assigned to the upper Maastrichtian based on the presence of Rhapydionina liburnica (BFA III) and rudist assemblage. A third emersion period of the platform corresponds to the early Maastrichtian.