Time filter

Source Type

Beidinger A.,University of Vienna | Beidinger A.,OMV Austria Exploration and Production GmbH | Decker K.,University of Vienna
Tectonics | Year: 2014

A detailed reconstruction of late Oligocene and Early Miocene thrusting at the leading edge of the East Alpine fold-thrust belt is achieved from well data, seismic, and interpretative cross sections. Data are used for constraining the paleogeographic positions of the Alpine thrusts, quantifying in-sequence/out-of-sequence thrust distances, assessing the timing of thrust propagation from structurally higher units into more external ones, and estimating thrust velocities. Results are depicted in five palinspastic maps for time slices between ∼26 Ma and ∼16 Ma. The termination of foreland-propagating thrusting at the Alpine front is apparently controlled by the subcrop topography of the European basement, which includes a major recess in the east leading to a diachronic along-strike termination of foreland-propagating thrusting with younger thrust ages and higher in-sequence thrust distances in the east. Early locking of foreland-propagating thrusting in the west causes prominent out-of-sequence thrusts which add to the in-sequence thrust distances there. Continuing consecutive detachment of foreland units in the east occurs at rather fast propagation velocities with time intervals between foreland-thrust-propagations ranging between 0.1 and 0.7 Ma. The resulting increase of in-sequence thrust distances from west to east is balanced by out-of-sequence thrusts in the west. The total amount of late Oligocene to Early Miocene thrusting is quantified with a minimum of 51 km. Average thrust velocities range between 4.6 and 5.2 mm/yr. This rate refers to the movement of the basal thrust at the leading edge of the fold-thrust belt, which occurs contemporaneous with the eastward lateral extrusion of the Eastern Alps in the hinterland. ©2014. American Geophysical Union. All Rights Reserved. Source

Gasparik M.,RWTH Aachen | Ghanizadeh A.,RWTH Aachen | Bertier P.,RWTH Aachen | Gensterblum Y.,RWTH Aachen | And 2 more authors.
Energy and Fuels | Year: 2012

High-pressure methane sorption isotherms were measured on one Paleozoic and five Mesozoic shales, considered as targets for shale gas exploration in The Netherlands. The samples varied in mineralogy, organic richness, and thermal maturity. Four of the samples were clay-rich (total clay content 60-71 wt %), one contained equal amounts of clays and quartz (36 wt % and 33 wt %, respectively) and one was a marl sample (clays 34 wt %, carbonates 49 wt %). The total organic carbon contents (TOC) ranged from <1 wt % to 10.5 wt %, and the thermal maturity, as inferred from Rock-Eval analysis, from immature to overmature. Excess (Gibbs) sorption isotherms for methane were measured at 65 °C on dry samples up to 25 MPa. The maximum excess sorption capacities within this pressure range varied from 0.05 to 0.3 mmol/g (1.1-6.8 m 3 STP/t). No correlation of excess sorption capacity with TOC was found. Low-TOC, clay-rich shales had comparable or even higher methane sorption capacities per unit rock mass (mmol/g) than organic-rich shales, and a positive correlation was found between the maximum Langmuir capacity (n L) and the clay content. This observation supports the notion that clay minerals can contribute significantly to the sorption capacity of shales. Furthermore, we demonstrate that significant errors in TOC-normalized sorption capacities may result from the uncertainties in TOC contents, especially at low TOC values. A comparison between the immature and the overmature sample (both organic-rich with equal clay contents) did not show any enhancement of the sorption capacity with thermal maturity. However, the excess sorption isotherm of the overmature sample had a distinct maximum, while no maximum was observed for the immature sample in the experimental pressure range. A Langmuir-type absolute sorption function, with a term taking the volume of the adsorbed phase explicitly into account, gave a good representation of the measured excess sorption isotherms. The three-parameter fit yielded the Langmuir parameters (n L and p L) and a nominal density value for the adsorbed phase (ρ ads). Two-parameter fits of n L and p L using different fixed values of ρ ads are discussed. © 2012 American Chemical Society. Source

Dellmour R.,OMV Austria Exploration and Production GmbH | Harzhauser M.,Natural History Museum Vienna
Marine and Petroleum Geology | Year: 2012

During the latest Early Miocene a large drainage system developed in the Alpine-Carpathian Foreland transporting sediments through a prominent submarine canyon along the narrow corridor between the south-eastern Bohemian Massif and the Waschberg-Ždánice Unit. The canyon followed the Alpine-Carpathian Foredeep from Lower Austria towards the north and northeast into the Czech Republic. 3-D seismic data allow the mapping of this 600 m deep structure over a distance of 25 km and a width of 5 km. Despite its dimension, making it the largest submarine erosive and sedimentary structure of the Neogene Alpine-Carpathian Foredeep, this canyon has not been previously recognised. Herein, it is interpreted as shelf-indenting canyon that formed due to a combination of isostatic rebound along a terminating thrust front and sea-level change during the terminal Early Miocene. The canyon fill comprises reworked littoral deposits with a typical Early Miocene, tropical micro- and macrofauna. The exact timing of this refilling remains unclear. Smaller channel structures in surface outcrops, representing potential tributaries of the canyon, suggest a more or less synsedimentary filling soon after indention. Finally, the top part of the canyon was eroded around the Early/Middle Miocene boundary, probably related to a global 3rd order sea level drop, and caped by marine marls during the subsequent early Middle Miocene transgression. With the sudden onset of the subsidence of the Northern Vienna Basin during that time, the drainage system abruptly moved southward shedding its sediments into the newly opening Vienna Basin. This explains the rather abrupt abandonment of the huge canyon feature, whose fan deposits are unknown so far. © 2012 Elsevier Ltd. Source

Hinderer M.,TU Darmstadt | Kastowski M.,TU Darmstadt | Kamelger A.,OMV Austria Exploration and Production GmbH | Bartolini C.,University of Florence | Schlunegger F.,University of Bern
Earth-Science Reviews | Year: 2013

This paper presents the first comprehensive analysis of sediment and dissolved load across an entire mountain range. We investigate patterns and rates of modern denudation of the European Alps based on a compilation of data about river loads and reservoir sedimentation from 202 drainage basins that are between ca. 1 to 10,000km2 large. The study basins cover about 50% of the total area of the Alps. Modern glaciated basins have the highest sediment yields of up to 7000tkm-2a-1, which are on average 5 to 10 times higher than in non-glaciated basins. Likewise sediment yield and glacial cover are positively correlated. Instead, relief is a relatively weak predictor of sediment yield. The strong glacial impact in the correlations is due to glacier recession since the 19th century as well as due to glacial conditioning during repeated Quaternary glaciations which have produced the strong transient state of the Alpine landscape. We suggest that this is the major cause for ca. 3 fold enhanced denudation of the western compared to the eastern Alps. Chemical denudation rates are highest in the external Alps dominated by carbonate sedimentary rocks, where they make up about one third of total denudation. The high rates cannot be explained without anhydrite dissolution. We estimated that only 45% of the sediments mobilized in headwaters are exported out off the Alps, most sediments being trapped in artificial reservoirs. The total amount of sediment annually trapped within the Alps equates to 43Mt. When corrected for sediment storage, we obtain an area-weighted mean total denudation rate for the Alps of about 0.32mma-1. The pre-dam rate might be as high as 0.42mma-1. In total, ca. 35 plus 23Mt of mass are exported each year out of the Alps as solids and solutes, respectively. These rates are not enough to out pace modern rock uplift. Nevertheless, pattern of sediment yield across the Alps coincides roughly with the intensity of glacial conditioning and modern rock uplift, supporting the hypothesis of an erosion-driven uplift of the Alps. © 2013 Elsevier B.V. Source

Vengudusamy B.,Ac2t Research Gmbh | Grafl A.,Ac2t Research Gmbh | Novotny-Farkas F.,OMV Austria Exploration and Production GmbH | Schofmann W.,Magna Powertrain AG and Co KG
Tribology International | Year: 2013

The friction responses of five fully formulated gear oils including mineral and synthetic oils were studied. This article examines the impact of contact motion types (rolling-sliding and pure sliding) and contact pressure on boundary and mixed friction properties of the selected gear oils in MTM (minitraction machine) and SRV (Schwing-Reib-Verschleiss tribometer). Mineral oils are found to be less affected by contact pressure compared to synthetic oils. Gear oils that show adsorption appear to be less sensitive to contact motion type in mixed lubrication while behave much more sensitive in boundary lubrication regimes. The ranking of gear oils for mixed friction was similar regardless of contact motion types at low contact pressures while differ at high contact pressures. © 2013 Elsevier Ltd. Source

Discover hidden collaborations