The Glueckstadt Graben, a sedimentary record between the North and Baltic Sea in north Central Europe   总被引：2，自引：1，他引：2  

Yuriy Maystrenko  Ulf Bayer  Magdalena Scheck-Wenderoth 《Tectonophysics》2005,397(1-2):113

The Glueckstadt Graben is one of the deepest post-Permian structures within the Central European Basin system and is located right at its “heart” at the transition from the North Sea to the Baltic Sea and from the Lower Saxony Basin to the Rynkoebing–Fyn High.The Mesozoic to recent evolution is investigated by use of selected seismic lines, seismic flattening and a 3D structural model. A major tectonic event in the latest Middle–Late Triassic (Keuper) was accompanied by strong salt tectonics within the Glueckstadt Graben. At that time, a rapid subsidence took place within the central part, which provides the “core” of the Glueckstadt Graben. The post-Triassic tectonic evolution of the area does not follow the typical scheme of thermal subsidence. In contrast, it seems that there is a slow progressive activation of salt movements triggered by the initial Triassic event. Starting with the Jurassic, the subsidence centre partitioned into two parts located adjacent to the Triassic “core.” In comparison with other areas of the Central European Basin system, the Glueckstadt Graben was not strongly affected by additional Jurassic and Cretaceous events. During the late Jurassic to Early Cretaceous, the area around the Glueckstadt Graben was affected by relative uplift with regional erosion of the elevated relief. However, subsidence was reactivated and accelerated during the Cenozoic when a strong subsidence centre developed in the North Sea. During Paleogene and Quaternary–Neogene, the two centres of sedimentation moved gradually towards the flanks of the basin.The data indeed point toward a control of post-Permian evolution by gradual withdrawal of salt triggered by the initial exhaustion along the Triassic subsidence centre. In this sense, the Glueckstadt Graben was formed at least partially as “basin scale rim syncline” during post-Permian times. The present day Hamburger, East and Westholstein Troughs are the actual final state of this long-term process which still may continue and may play a role in terms of young processes and, e.g., for coastal protection.  相似文献   

Structure and evolution of the Glueckstadt Graben due to salt movements     

Yuriy Maystrenko  Ulf Bayer  Magdalena Scheck-Wenderoth 《International Journal of Earth Sciences》2005,94(5-6):799-814

The salt tectonics of the Glueckstadt Graben has been investigated in relation to major tectonic events within the basin. The lithologic features of salt sections from Rotliegend, Zechstein and Keuper show that almost pure salt is prominent in the Zechstein, dominating diapiric movements that have influenced the regional evolution of the Glueckstadt Graben. Three main phases of growth of the salt structures have been identified from the analysis of the seismic pattern. The strongest salt movements occurred at the beginning of the Keuper when the area was affected by extension. This activation of salt tectonics was followed by a Jurassic extensional event in the Pompeckj Block and Lower Saxony Basin and possibly in the Glueckstadt Graben. The Paleogene–Neogene tectonic event caused significant growth and amplification of the salt structures mainly at the margins of the basin. This event was extensional with a possible horizontal component of the tectonic movements. 3D modelling shows that the distribution of the initial thickness of the Permian salt controls the structural style of the basin, regionally. Where salt was thick, salt diapirs and walls formed and where salt was relatively thin, simple salt pillows and shallow anticlines developed.  相似文献   

Isotopic and hydrochemical studies of groundwater flow and salinity in the Southern Upper Rhine Graben     

Michael Bauer  Lorenz Eichinger  Philippe Elsass  Wolfram Kloppmann  Gunther Wirsing 《International Journal of Earth Sciences》2005,94(4):565-579

In order to determine the origin and the propagation mechanisms of highly concentrated chloride brines within the Quaternary aquifer system in the southern part of the Upper Rhine Graben, a combined isotope (H, O, C) and hydrochemical analysis was carried out. Groundwater recharge in this area is a complex system, consisting of local precipitation, river bank filtration, lateral flow from the Graben borders and, to a minor extent, an old Pleistocene component. In some areas, groundwater consists of up to 90% of recent bank filtrate, reaching depths down to at least 100 m. The isotopic and hydrochemical results show, that the elevated chloride concentrations in the Quaternary aquifer mainly result from leaky settling basins charged by the French potash mines until the mid 1970s. Input of natural brines coming from tertiary salt diapirs is of only minor importance. While infiltrating, the anthropogenic brines were strongly diluted by local river bank filtrate of the Rhine. Nevertheless, maximum chloride concentrations nowadays still reach some 10,000 mg/l at the base of the aquifer at a depth of more than 100 m below surface. The main volume of the brines is stored in the less permeable lower part of the quaternary sediments (Breisgau-Formation) whereas only a minor part is transported northwards with the rapid convective groundwater flow. Brines undergoing only dilution preserve their hydrochemical characteristics (NaCl-type). In contrast, brines recirculated from the Breisgau-Formation show a northwards increasing alteration through ion exchange processes. Potassium and sodium may be fixed in the fine grained aquifer material while calcium is set free into the groundwater. After a flow distance of about 12 km, complex hydraulic interactions between groundwater and surface waters lead to the rise of strongly diluted and hydrochemically altered brines with chloride contents up to maximum 700 mg/l. The presented case study is an example for a detailed analysis of a multi-component groundwater mixing system using combined isotope and hydrochemical methods. Furthermore, cation exchange is shown as a major process affecting the hydrochemical evolution of the young groundwater in the southern Upper Rhine Graben which is locally strongly polluted by chloride as a consequence of former potash mining.  相似文献   

Late Cenozoic evolution of epithermal gold metallogenic provinces in Kyushu, Japan     

Yasushi Watanabe 《Mineralium Deposita》2005,40(3):307-323

Kyushu Island, Japan, is located at the junction of the Southwest Japan arc and the Ryukyu arc. There are two major late Cenozoic epithermal gold-silver provinces in Kyushu, which are termed the Northern and Southern provinces. The provinces are characterized by: 1) Pliocene volcanism dominated by calc-alkaline andesite, followed by Quaternary volcanism including extrusion of both calc-alkaline and tholeiitic magmas; 2) formation of extensional grabens; 3) Pliocene to Pleistocene mineralization, which was dominated by abundant low sulfidation (LS) epithermal deposits with a few high sulfidation (HS) examples. The two epithermal gold-silver provinces have evolved differently since about 5 Ma; the Northern province has exhibited diminished hydrothermal activity from the Pliocene to Pleistocene, whereas the Southern province has witnessed increased hydrothermal activity mainly in easterly and northerly directions. Changes of tectonic setting from the Pliocene to Pleistocene account for the variable trends in epithermal gold deposit formation. Westward oblique subduction of the Philippine Sea plate beneath the Southwest Japan arc caused development of the Hohi graben and arc-related volcanism at about 6 Ma. This was associated with widespread LS mineralization in and surrounding the Hohi graben, as is represented by the Bajo and Taio deposits. The subduction of the relatively buoyant Kyushu-Palau ridge during the early Pliocene strengthened the coupling between the slab and overriding Ryukyu arc, leading to polygenetic andesite volcanism with associated HS (Kasuga, Iwato, and Akeshi) and LS (Kushikino) mineral deposits forming in the Southern province. A change of the subduction direction of the Philippine Sea plate, from west to north-northwest in the early Pliocene, increased the orthogonal convergence rate between the Southwest Japan arc and the Philippine Sea plate, resulting in a decrease of volcanic and hydrothermal activity in the Hohi graben of the Northern province. The more northerly subduction of the Philippine Sea plate shifted the locus of the Kyushu-Palau ridge subduction northward, resulting in underplating of the older (85–60 Ma), negatively buoyant Amami basin oceanic slab in the Southern province, rather than continued subduction of the young (27–15 Ma), buoyant Shikoku basin slab. This replacement caused steepening of the slab angle and slab-rollback in the Southern province, which was associated with regional extension, an eastward shift of the Ryukyu volcanic front, and development of the Kagoshima and Shimabara grabens, as well as the Okinawa trough. Rhyolite and basalt volcanism, in addition to andesite volcanism, have occurred since 2 Ma in the area of the Ryukyu back arc; coincident LS mineralization at Hishikari and Ohkuchi was affiliated with the rhyolite volcanism. Another change of the subduction direction of the Philippine Sea plate to the northwest occurred at 2–1 Ma. The forearc sliver of the Southwest Japan arc shifted westward, in association with right-lateral strike-slip faulting along the Median tectonic line, due to the increase of the westward convergence rate. This shift resulted in shortening and cessation of graben development in the Hohi area, restricting the subsequent volcanism and related hydrothermal activity to the central part of the graben.  相似文献   

Evolution and structure of the Upper Rhine Graben: insights from three-dimensional thermomechanical modelling     

Michael Schwarz  Andreas Henk 《International Journal of Earth Sciences》2005,94(4):732-750

The evolution and geometry of the Tertiary Upper Rhine Graben were controlled by a continually changing stress field and the reactivation of pre-existing crustal discontinuities. A period of WNW-ESE extension in the late Eocene and Oligocene was followed by lateral translation from the early Miocene onwards. This study utilizes 3D finite element techniques to simulate extension and lateral translation on a lithospheric scale. Brittle and creep behaviour of lithospheric rocks are represented by elastoplasticity and thermally activated power-law viscoplasticity, respectively. Contact elements allocated with cohesion and frictional coefficients are used to describe pre-existing zones of weakness in the elastic-brittle field. Our results suggest that (1) extension is accommodated along listric border faults to midcrustal depth of 15–16 km. Beneath, pure shear stretching occurs without a need for localized shear zones in lower crust and upper mantle. (2) Ductile flow at midcrustal depth across the graben accounts for the pronounced halfgraben morphology. Thereby, the shape of the border faults, their frictional coefficients, and sedimentary loads have profound effects on the rate of ductile flow across the graben. (3) Horizontal extension of 8–8.5 km and sinistral displacement across the rift of 3–4 km are needed to accommodate the observed sediment thickness.  相似文献   

基于位场信息的伊舒地堑莫里青断陷西北缘断裂性质   总被引：2，自引：2，他引：2  

刘万崧  周云轩  卢炎  许惠平 《吉林大学学报(地球科学版)》2005,(Z1)

伊舒地堑边缘断裂不仅控制了盆地的空间形态,而且在很大程度上控制了盆地的结构、构造发育特征和盖层沉积。本文利用1∶5万重、磁资料研究了地堑内莫里青断陷西北缘断裂性质,得出了区内NE—SW向断裂为边界主断裂,呈现出张性特征,属高角度正断层,近EW向断裂,呈现出压性特征,属高角度逆断层的结论。  相似文献   

Subsurface structure of the volcanic centre of the České Středohoří Mountains, North Bohemia, determined by geophysical surveys     

J. Mrlina  V. Cajz 《Studia Geophysica et Geodaetica》2006,50(1):75-88

Former geophysical surveys performed in the region of the volcanic centre of the České Stř edohoří Mts. in North Bohemia (the Ohře Rift zone) showed that anomalous volcanic bodies and features can be effectively identified within sedimentary environment. For this reason we carried out new geophysical measurements in the area of the main mafic intrusion of essexitic character. The target was the exact location and geometry of the intrusion and its relation to other components of the volcanic centre. We used gravity, magnetic, shallow seismic and electromagnetic techniques. The new gravity and magnetic data were tied to the old databases so that we could investigate the area as a whole complex. Electromagnetic measurements were applied in the area of the expected extent of the intrusion, and the seismic measurements in the central part of the intrusion. Based on all the data, mainly on gravity modelling, we delineated not only the surface and subsurface extent of the intrusion, but we also defined the hidden relief of the intrusion. It was found that the intrusion is formed by a single body that has a few protrusions, and not by a set of separate individual intrusions, as indicated by surface outcrops. However, the body of the intrusion is affected by a major fault that caused lithological differences on both sides (essexite/monzodiorite). In detail we show the depth of the debris cover and the thickness of the weathered zone in the central part of the essexite body. We also derived indications of tectonic elements in the area of the intrusion in the main structural/tectonic direction in the region. The results will be utilized to establish a 3D geological model of the whole volcanic centre. This investigation may serve as an example of non-seismic geophysical exploration applied to the study of volcanic centres surrounded by sedimentary rocks.  相似文献   

Cenozoic “radiobarite” occurrences in the Ohře (Eger) Rift, Bohemian Massif: Mineralogical and geochemical revision     

J. Ulrych  J. Adamovic   K. k  J. Frna  Z. &#x;anda  A. Langrov  R. Skla  M. Chvtal 《Chemie der Erde / Geochemistry》2007,67(4):301-312

Barite occurrences related to the Cenozoic (Late Alpine) low-temperature hydrothermal activity are present in the continental Ohře (Eger) Rift area. A specific, Ra-bearing type of barite has been known under the name “radiobarite” from this area since 1904. Revision of 12 localities revealed the presence of alleged radiobarite only in the Teplice (Lahošť–Jeníkov) and Karlovy Vary areas. Barite from other localities is radium-poor. Barite crystals showing concentric oscillation colour zoning totally prevail. Isomorphous substitution of Sr (X×10⁻¹ to X×wt%), Ca (X×10⁻² wt%) and Fe (X×10⁻¹ wt%) for Ba was proved. Average SrO contents of 0.4 wt% are markedly exceeded in some samples from Lahošť–Jeníkov (max. 3.2 wt%) and Karlovy Vary (max. 4.9 wt%). Besides inclusions of stoichiometric iron disulphide, the same samples also contain iron disulphides with unusual high contents of Co (max. 12.2 wt%) and Ni (max. to 8.4 wt%). Specific activity of ²³⁸U in the studied barites is very low while that of ²²⁶Ra reaches 8 Bq/g in several samples. Therefore, ²²⁶Ra is not in equilibrium with its parent uranium. These “radiobarites” or their parts must be therefore relatively young, not older than 10–15 ka. Very low uranium contents (<0.4 ppm) were also confirmed by neutron activation analyses of barite samples.

Unit-cell dimensions refined from X-ray powder diffraction data do not show any systematic variation with the measured chemical composition. Their values agree with the data given in the literature. Reflection half-widths, however, seem to correlate with chemistry. Peaks are wider in samples from Lahošť–Jeníkov and Karlovy Vary.

Sulphur and oxygen stable isotope compositions of the Cenozoic barite mineralization of Teplice area are very uniform (δ³⁴S values between 3.9‰ and 7.1‰ CDT, and δ¹⁸O values between 6.1‰ and 7.7‰ SMOW), while the barites of Děc˘ín area show more variable sulphur sources. Sulphate derived from sediments of the Tertiary Most Basin seems to dominate for the Teplice area, while Cretaceous sediments are a more probable sulphur source in the Děc˘ín area. Calculation of oxygen isotope composition of hydrothermal fluids based on fluid inclusion homogenization temperatures and barite δ¹⁸O data shows δ¹⁸O_fluid values in the range of meteoric waters or δ¹⁸O – shifted deep circulating meteoric or basinal waters.  相似文献   

Numerical modelling of chloride propagation in the quaternary aquifer of the southern Upper Rhine Graben     

U. Lang  T. Gudera  P. Elsass  G. Wirsing 《International Journal of Earth Sciences》2005,94(4):550-564

The deep groundwater in the quaternary gravel sequence of the southern Upper Rhine Graben locally contains high chloride concentrations near the river Rhine between Fessenheim (France) in the South and Breisach (Germany) in the North. This historical pollution is mainly due to past infiltration from the former brine storage basins of the French potash mines on the Fessenheim Island and—to a lesser extent—from the leaching of the salt dumps of the German potash mines in Buggingen and Heitersheim. The spreading of the salt plume was investigated by means of a groundwater model. The aim of the model was to understand the brine movement, the present distribution of chloride as defined by recent hydrochemical investigations, and to select locations for new reconnaissance boreholes. The geological structure was reproduced by a three layer model, which was calibrated for steady state flow conditions. The hydraulic conductivity of the first layer was determined by comparing measured and calculated heads in the model area. The vertical resolution was refined to simulate the density-dependent salt transport processes. The transport of the salt plumes was simulated over a 40-year period, starting at the beginning of brine storage in the 1950s. The relevant transport parameters have been estimated in a sensitivity analysis, where the simulated breakthrough curves of chloride concentration have been compared with the measured data. The results of the groundwater model indicate that brines containing approximately 1 million tons of chloride are still present at the bottom of the aquifer. These highly concentrated salt brines mix with fresh water from the upper part of the aquifer. This dispersive process leads to the formation of a plume of chloride-rich water extending downstream, where pumping wells for several local water supplies are located.  相似文献   

Tectonosedimentary Evolution of the Cheb Basin (NW Bohemia,Czech Republic) between Late Oligocene and Pliocene: A Preliminary Note     

Špičáková  L.  Uličný  D.  Koudelková  G. 《Studia Geophysica et Geodaetica》2000,44(4):556-580

A working model of tectono-sedimentary evolution is proposed for the Cheb Basin, a polyhistory sedimentary basin formed between the late Oligocene and Pliocene by reactivation of basement fracture systems in the northwestern part of the Bohemian Massif. The basin is located at the intersection of the Ohe (Eger) Graben structural domain, characterized by dominance of NE-striking graben systems in present-day geology, and the NW-striking Cheb-Domalice Graben, a major strike-slip – dominated structure in Western Bohemia. The first significant depositional episode in the Cheb Basin coincides with the deposition of late Oligocene-Miocene clastics in the whole extensional system of the Ohe Graben, controlled by E-W – trending depocenters. The main structural feature of the Cheb Basin region at that time was a palaeohigh caused by a NW- trending accommodation zone separating minor E-W – trending depocentres. The second, late Pliocene, episode of sedimentation occurred under a very different kinematic regime than the Oligo-Miocene rift basin evolution. During this time, the present-day structure of the Cheb Basin and the Cheb-Domalice Graben formed as a consequence of sinistral displacement on the Mariánské Lázn Fault Zone. Reactivation of this strike-slip fault zone led to the formation of a horsetail splay of oblique-extensional faults at the northern termination of the Mariánské Lázn Fault Zone, which contained the present-day Cheb Basin.  相似文献