Late Pleistocene fluvial dynamics in the Hochrhein Valley and in the Upper Rhine Graben: chronological frame

During the Pleistocene, the Rhine glacier system acted as a major south–north erosion and transport medium from the Swiss Alps into the Upper Rhine Graben, which has been the main sediment sink forming low angle debris fans. Only some aggradation resulted in the formation of terraces. Optically stimulated luminescence (OSL) and radiocarbon dating have been applied to set up a more reliable chronological frame of Late Pleistocene and Holocene fluvial activity in the western Hochrhein Valley and in the southern part of the Upper Rhine Graben. The stratigraphically oldest deposits exposed, a braided-river facies, yielded OSL age estimates ranging from 59.6 ± 6.2 to 33.1 ± 3.0 ka. The data set does not enable to distinguish between a linear age increase triggered by a continuous autocyclical aggradation or two (or more) age clusters, for example around 35 ka and around 55 ka, triggered by climate change, including stadial and interstadial periods (sensu Dansgaard–Oeschger cycles). The braided river facies is discontinuously (hiatus) covered by coarse-grained gravel-rich sediments deposited most likely during a single event or short-time period of major melt water discharge postdating the Last Glacial Maximum. OSL age estimates of fluvial and aeolian sediments from the above coarse-grained sediment layer are between 16.4 ± 0.8 and 10.6 ± 0.5 ka, and make a correlation with the Late Glacial period very likely. The youngest fluvial aggradation period correlates to the beginning of the Little Ice Age, as confirmed by OSL and radiocarbon ages.     

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欧洲和远东第四纪陆相堆积的生物地层对比(哺乳动物)

在晚第三纪晚期和第四纪时,欧亚大陆古动物群的面貌受两个陆桥的影响很大,在尽西边有一个复合陆桥,即非洲与欧洲相连,与亚洲沿着非洲西边—伊比利亚半岛连接;中间的非洲—西西里岛陆桥和一个东地中海陆桥(非洲—阿拉伯半岛)连接。     

The SHARE European Earthquake Catalogue (SHEEC) for the time period 1900–2006 and its comparison to the European-Mediterranean Earthquake Catalogue (EMEC)

This short communication describes the differences of the seismicity data file of the SHARE European Earthquake Catalogue from 1900 to 2006 in comparison to the European-Mediterranean Earthquake Catalogue by Grünthal and Wahlström (J Seismol 16:535–570, 2012). SHARE is the EC project Seismic Hazard Harmonization in Europe. Differences occur in the very north of the study area, in Greece and adjacent areas, and with respect to local volcanic earthquakes at Etna, Italy.     

Der Laurier Belt,Eine Rotationszone Zwischen Kern-Orogen und Saumsenke (Kanadische Rocky Mountains)

Between Lat. 56° N and 57° 30′ N, the Central Ranges of the Canadian Rocky Mountains contain a belt of slaty-cleaved vertical or overturned east-dipping beds which is considered as the west edge of the thrust-faulted area. Its antithetic rotation is accompanied by small-scale folding parallel to the plane of greatest shear stress, by synthetic and later antithetic movements along the plane of slaty cleavage. Reversal of movement on older reverse faults and a discordant, post-Laramide phase of synthetic normal faulting terminate the movements. Folding and rotation are contemporaneous with the thrusting to the east, and the synthetic normal faulting belongs to the grabening of the Rocky Mountain Trench adjacent to the east. Since rotation and thrusting above the uninvolved basement are contemporaneous, the rotation cannot be powered by differential movement along a stationary lineament within the basement. Its cause is suspected in the west-dipping clinoforms of the Palaeozoic sediments whose inclination placed them within the antithetic quadrant of the Laramide stress field, forcing them to continue rotation and to develop compressional folding instead of bedding-parallel elongated thrust sheets. One of two structurally analogous cases, the Swiss Massif Zone with the Helvetic nappes, shows an antithetically inclined gneissic foliation which might be a mechanical equivalent of the clinoforms in the Rocky Mountains. In the other example, from the north flank of the Hercynian Mosel syncline, a remarkably similar tectonic history and a close geographic coincidence between clinoformic sedimentation and development of an antithetic rotation zone is known.     

Magmatic evolution of the Easter microplate-Crough Seamount region (South East Pacific)

The Easter microplate-Crough Seamount region located between 25° S–116° W and 25° S–122° W consists of a chain of seamounts forming isolated volcanoes and elongated (100–200 km in length) en echelon volcanic ridges oriented obliquely NE (N 065°), to the present day general spreading direction (N 100°) of the Pacific-Nazca plates. The extension of this seamount chain into the southwestern edge of the Easter microplate near 26°30 S–115° W was surveyed and sampled. The southern boundary including the Orongo fracture zone and other shallow ridges (< 2000 m high) bounding the Southwest Rift of the microplate consists of fault scarps where pillow lava, dolerite, and metabasalts are exposed. The degree of rock alternation inferred from palagonitization of glassy margins suggests that the volcanic ridges are as old as the shallow ridges bounding the Southwest Rift of the microplate. The volcanics found on the various structures west of the microplate consist of depleted (K/Ti < 0.1), transitional (K/Ti = 0.11–0.25) and enriched (K/Ti > 0.25) MORBs which are similar in composition to other more recent basalts from the Southwest and East Rifts spreading axes of the Easter microplate. Incompatible element ratios normalized to chondrite values [(Ce/Yb)_N = 1–2.5}, {(La/Sm)_N = 0.4–1.2} and {(Zr/Y)_N = 0.7–2.5} of the basalts are also similar to present day volcanism found in the Easter microplate. The volcanics from the Easter microplate-Crough region are unrelated to other known South Pacific intraplate magmatism (i.e. Society, Pitcairn, and Salas y Gomez Islands). Instead their range in incompatible element ratios is comparable to the submarine basalts from the recently investigated Ahu and Umu volcanic field (Easter hotspot) (Scientific Party SO80, 1993) and centered at about 80 km west of Easter Island. The oblique ridges and their associated seamounts are likely to represent ancient leaky transform faults created during the initial stage of the Easter microplate formation ( 5 Ma). It appears that volcanic activity on seamounts overlying the oblique volcanic ridges has continued during their westward drift from the microplate as shown by the presence of relatively fresh lava observed on one of these structures, namely the first Oblique Volcanic Ridge near 25° S–118° W at about 160 km west of the Easter microplate West Rift. Based on a reconstruction of the Easter microplate, it is suggested that the Crough seamount (< 800 m depth) was formed by earlier (7–10 Ma) hotspot magmatic activity which also created Easter Island.     

Agent-based simulation for biogas power plant potential in Schwarzwald-Baar-Kreis,Germany: a step towards better economy

Over the past decade, political framework in the energy sector all over the world has provoked a strong focus on the production of renewable energies. The study focuses on agent-based modelling approach to identify the suitable and economical distribution of biogas power plants over time in the area of interest. For sufficient supply of biomass (silage maize) on a regional basis to run biogas power plants economically and smoothly, different thematic layers with defined rules for Agent Analyst used to simulate the future installations of power plants. In conjunction with ArcGIS, the Agent Analyst software generates simulations that prove the robustness of the model in finding the suitable location of power plants. The resultant location from the model is analysed in different aspects. The designed methodology could be implemented in other areas with minor edits as per requirement of the area.     

Geothermal problems in mountain ranges (Alps)

An attempt has been made to model the temperature distribution taking into account simultaneously the effects of regional uplift and erosion, present topography, development of topography with time and paleoclimatic variations.Two time intervals were considered: a long period (30 m.y.) for the uplift history and a relatively short period (200,000 y) for the surface history (topography, climate).The calculations were based on finite differences in space and time. An example is presented for an area in the Swiss Alps, where observed rock temperatures in a tunnel and paleotemperature data are available. A simple uplift history can fit the paleotemperatures but leads to unrealistic high temperatures in greater depths. To improve the model frictional heat sources due to crustal overthrusting were introduced.