scholarly journals The Oligocene Reifnitz tonalite (Austria) and its host rocks: implications for Cretaceous and Oligocene–Neogene tectonics of the south-eastern Eastern Alps

2018 ◽  
Vol 69 (3) ◽  
pp. 237-253 ◽  
Author(s):  
Franz Neubauer ◽  
Bianca Heberer ◽  
István Dunkl ◽  
Xiaoming Liu ◽  
Manfred Bernroider ◽  
...  

Abstract In the south-eastern Eastern Alps, the Reifnitz tonalite intruded into the Austroalpine metamorphic basement of the Wörthersee half-window exposed north of the Sarmatian–Pliocene flexural Klagenfurt basin. The Reifnitz tonalite is dated for the first time, and yields a laser ICP-MS U–Pb zircon age of 30.72±0.30 Ma. The (U–Th–Sm)/He apatite age of the tonalite is 27.6 ± 1.8 Ma implying rapid Late Oligocene cooling of the tonalite to ca. 60 °C. The Reifnitz tonalite intruded into a retrogressed amphibolite-grade metamorphic basement with a metamorphic overprint of Cretaceous age (40Ar/39Ar white mica plateau age of 90.7 ± 1.6 Ma). This fact indicates that pervasive Alpine metamorphism of Cretaceous age extends southwards almost up to the Periadriatic fault. Based on the exhumation and erosion history of the Reifnitz tonalite and the hosting Wörthersee half window formed by the Wörthersee anticline, the age of gentle folding of Austroalpine units in the south-eastern part of the Eastern Alps is likely of Oligocene age. North of the Wörthersee antiform, Upper Cretaceous–Eocene, Oligocene and Miocene sedimentary rocks of the Krappfeld basin are preserved in a gentle synform, suggesting that the top of the Krappfeld basin has always been near the Earth’s surface since the Late Cretaceous. The new data imply, therefore, that the Reifnitz tonalite is part of a post-30 Ma antiform, which was likely exhumed, uplifted and eroded in two steps. In the first step, which is dated to ca. 31–27 Ma, rapid cooling to ca. 60 °C and exhumation occurred in an E–W trending antiform, which formed as a result of a regional N–S compression. In the second step of the Sarmatian–Pliocene age a final exhumation occurred in the peripheral bulge in response to the lithospheric flexure in front of the overriding North Karawanken thrust sheet. The Klagenfurt basin developed as a flexural basin at the northern front of the North Karawanken, which represent a transpressive thrust sheet of a positive flower structure related to the final activity along the Periadriatic fault. In the Eastern Alps, on a large scale, the distribution of Periadriatic plutons and volcanics seems to monitor a northward or eastward shift of magmatic activity, with the main phase of intrusions ca. 30 Ma at the fault itself.

2010 ◽  
Vol 28 (10) ◽  
pp. 1905-1922 ◽  
Author(s):  
M. T. Prtenjak ◽  
I. Tomažić ◽  
I. Kavčič ◽  
S. Đivanović

Abstract. Characteristics of thermally induced flow, namely the sea breeze, are investigated along the south-eastern Adriatic. The chosen period 24–25 April 2006 favoured sea breeze development and simultaneously allowed a comparison of the large-scale wind influence (north-westerly wind versus south-easterly wind) and the complex terrain on the local circulations. Particular attention is paid to the small-scale formation of the wind field, convergence zones (CZs), channelling flows and small scale eddies, especially in the vicinity of two airports in the central part of south-eastern Adriatic. The results are based on wind measurements (from meteorological surface stations, radiosoundings, satellite data and sodar data) and further supplemented by model data at fine grid spacing. This study shows the formation of numerous irregular daytime and nighttime CZs, which occurred along the coastline in the lee of mountains and over the larger, elongated islands. The results show that the above mentioned airports are surrounded by daytime CZ formations within the lowermost 1000 m and associated updrafts of 1 m s−1, especially if CZs are maintained by the north-westerly large-scale winds. Whereas the daytime CZ was generated due to merged sea breezes, the weaker and shallower nighttime CZs were formed by wind convergence of the seaward breezes, and significantly modified by the large-scale flow of the topography (e.g., accelerated flow in the sea channels and substantial swirled flows around the islands). The passes between the coastal mountain peaks changed the inflow penetration, provoking the increase in wind speed of the channelled flow. The strongest sea breeze channelling was observed above the valley of the Neretva River, where the onshore flow reached 40 km inland with a strength of 8 m s−1, and the highly asymmetric offshore part was confined within the sea channel.


1916 ◽  
Vol 3 (10) ◽  
pp. 435-441 ◽  
Author(s):  
G. W. Tyrrell

The new material on which this paper is based has lately been received through Mr. D. Ferguson, who recently investigated the geology of the island, and collected the rocks described in an earlier paper. It consists of twenty-seven rock specimens from the south-eastern end of the island, between Cape Disappointment and Cooper Island, and nine specimens from Gold Harbour on the north-east coast between Cooper Island and Royal Bay. All these were collected by the staff of the South Georgia Co., Ltd., under the instructions of Mr. Th. E. Salvesen, managing director, of Leith.


2021 ◽  
Vol 38 ◽  
pp. 00102
Author(s):  
Ekaterina Popova ◽  
Evgeniy Sinkovskiy

The paper presents a taxonomic, areographic and belt-andzonal analysis of the high-mountain flora of the Kurai Ridge. The flora of the region in question contains 312 species of plants, referred to 143 genera belonging to 48 families. Analysis of the taxonomic structure of the high-mountain flora of the Kurai Ridge has shown the following most abundant plant families: Asteraceae, Ranunculaceae, and Poaceae. For the variety of the genera, the following genera are predominant: Carex, Pedicularis, Salix, and Oxytropis. The areographic analysis has demonstrated that the said species are of the North Asian (21 %), South Siberian (19.4 %) and Holarctic (17.4 %) origins. Dominant in the belt-and-zonal range are the following species: high-mountain (23.2 %), light-coniferous forest (17.7 %) and Arctic Alpine (17.4 %) species. In general, the composition and structure of the high-mountain flora of the Kurai Ridge are determined by its geographic position at the boundary of Central and South-Eastern Altai and by decrease in the amount of precipitation in the south-eastern direction.


1906 ◽  
Vol 12 ◽  
pp. 415-430
Author(s):  
Ramsay Traquair

In plan the walls surrounding the Acropolis of Sparta form an irregular oblong, terminated to the east and west by two small hills which formed citadels or outlook points. Though no single complete part remains, and in many places the walls are levelled to the ground, the lines can still be traced fairly completely. (Plate VIII. 3.)At the south eastern corner are the ruins of a Roman Stoa of the Imperial period (A). They shew a series of small compartments (Fig. 1), covered with barrel vaults, ten on either side of three larger central rooms, which are roofed with crossgroined vaults and large semicircular niches at the back. The ground on the north side is as high as the vaults and originally must have formed a terrace overlooking the street on to which the Stoa opened on its south side.


2019 ◽  
Vol 147 (4) ◽  
pp. 1415-1428 ◽  
Author(s):  
Imme Benedict ◽  
Karianne Ødemark ◽  
Thomas Nipen ◽  
Richard Moore

Abstract A climatology of extreme cold season precipitation events in Norway from 1979 to 2014 is presented, based on the 99th percentile of the 24-h accumulated precipitation. Three regions, termed north, west, and south are identified, each exhibiting a unique seasonal distribution. There is a proclivity for events to occur during the positive phase of the NAO. The result is statistically significant at the 95th percentile for the north and west regions. An overarching hypothesis of this work is that anomalous moisture flux, or so-called atmospheric rivers (ARs), are integral to extreme precipitation events during the Norwegian cold season. An objective analysis of the integrated vapor transport illustrates that more than 85% of the events are associated with ARs. An empirical orthogonal function and fuzzy cluster technique is used to identify the large-scale weather patterns conducive to the moisture flux and extreme precipitation. Five days before the event and for each of the three regions, two patterns are found. The first represents an intense, southward-shifted jet with a southwest–northeast orientation. The second identifies a weak, northward-shifted, zonal jet. As the event approaches, regional differences become more apparent. The distinctive flow pattern conducive to orographically enhanced precipitation emerges in the two clusters for each region. For the north and west regions, this entails primarily zonal flow impinging upon the south–north-orientated topography, the difference being the latitude of the strong flow. In contrast, the south region exhibits a significant southerly component to the flow.


1954 ◽  
Vol 2 (16) ◽  
pp. 423-428

AbstractMorsárjökull is a small outlet glacier of Vatnajökull, Iceland. Two outlet streams from the ice cap unite at the foot of a precipitous step and carry a well-developed medial moraine; the north-west glacier stream is fed by a steep ice fall, the south-eastern one has been fed only by avalanches since 1938.The movement of the glacier was measured and showed that the alternate dark and light ogives were one year’s movement apart. Their characteristics are described and tentative suggestions concerning their mode of origin are proposed.


Inner Asia ◽  
2002 ◽  
Vol 4 (2) ◽  
pp. 361-373
Author(s):  
Elke Studer

AbstractThe article outlines the Mongolian influences on the biggest horse race festival in Nagchu prefecture in the Tibetan Autonomous Region (TAR).Since old times these horse races have been closely linked to the worship of the local mountain deity by the patrilineal nomadic clans of the South-Eastern Changthang, the North Tibetan plain. In the seventeenth century the West Mongol chieftain Güüshi Khan shaped the history of Tibet. To support his political claims, he enlarged the horse race festival's size and scale, and had his troops compete in the different horse race and archery competitions in Nagchu. Since then, the winners of the big race are celebrated side by side with the political achievements and claims of the central government in power.


2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Joint Archaeological Team Of Instit ◽  
Suzhou Municipal Institute Of Archa

AbstractIn 2009 and 2010, a series of archaeological investigations were conducted in and around the Mudu archaic city site located in the southwestern highland of Greater Suzhou, Jiangsu. The excavations revealed sections of the north circumference wall at Wufeng and the water gate of the south circumference wall at Xinfeng. The surveys identified the possible locations of the east and the west circumference walls. Diagnostic proto-porcelain and stamped potsherds were recovered. It is tentatively argued that both the north and the south walls were built and in use during the late Spring-and-Autumn Period. The Mudu Site, therefore, was a large-scale walled settlement functioned as a regional center of its time. These findings are instrumental in the search for the lost capital of Wu State of the Spring-and-Autumn Period, the understanding of the relationship among the various contemporary settlement sites, cairns, earthen mounds, and caches distributed in the region, and the reconstruction of the local cultural history of Eastern Zhou.


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