The Moho Structure in The Western Eger Rift: A Receiver Function Experiment     

Geissler  Wolfram  Plenefisch  Thomas  Kind  Reiner  Klinge  Klaus  Kämpf  Horst  Boušková  Alena  Nehybka  Vladimír  Skácelová  Zuzana  Jacob  Brian 《Studia Geophysica et Geodaetica》2000,44(2):188-194

We used teleseismic recordings of a temporary deployment of seismic stations and of permanent short period stations in the western Eger Rift system to study the lithosphere with the help of Receiver Functions. The crust-mantle boundary (Moho) is observed at almost all stations by strong P-to-S converted phases. The Moho is basically flat between about 26 – 30 km depth in the entire region. At one station in the Eger Rift (BOH-1, Loket castle) no Moho is observed. We interpret this with the existence of a broad gradient zone there, instead of a sharp discontinuity. This observation, however, needs to be confirmed by more data.  相似文献   

Origin of the deep fluids in the paleosubduction zones in western Tianshan: Evidence from Pb- and Sr-isotope compositions of high-pressure veins and host rocks     

Reiner Klemd 《中国科学D辑(英文版)》2005,48(10)

Fluids in the deep subduction zones play an impor-tant role in the process of crust-mantle interaction. This has been proved by a large number of studies on the geochemistry of island arc volcanic rocks[1―9]. Study on high-pressure metamorphic rocks within orogen shows that the dehydration and devolatilization of subducted oceanic crust and sediments can release amounts of water during progressive metamorph- ism[10―13]. The origin of the fluids in the subduction zones provides important info…  相似文献   

Methane Production, Emission and Possible Control Measures in the Rice Agriculture   总被引：19，自引：0，他引：19  

Wang Mingxing  Shangguan Xingjian  Shen Renxing  Wassmann Reiner  Seiler Wolfgang 《大气科学进展》1993,10(3):307-314

In the rice field methane is produced in the soil layer with depths of 2-25 cm. The vertical profile of methane production rate in the paddy soil during the water covering period differs from that in the paddy soil in dry phase. Only a small part, about 30%. of the produced methane is emitted to the atmosphere through rice plant, air bubbles, and molecular diffusion. Therefore, the methane emission rate from the rice field depends not only on the methane production rate in the soil, but also on the transport efficiency of the rice plant, air bubble formation that in turn depends on the production rate, and molecular diffusion.Field measurements show that methane emission rates from a particular rice field have very large diurnal, seasonal and interannual variations, which are related to soil characteristics, water regime, farming procedure, local climate, and rice growing activities. The relationship between the methane emission rate and the above mentioned factors is very complicated. The emission rate  相似文献   

Flame Emission for Accurate Cesium Determination in Geostandards     

Reiner GOGUEL 《Geostandards and Geoanalytical Research》1981,5(1):95-99

Cesium values for 21 geostandards obtained by flame emission spectrometry are presented. Analytical sensitivity was separately determined for each sample by the method of standard addition to cancel effects of chemical interferences. Three types of chemical interferences have been found and their magnitude has been measured. Correction factors have been derived to improve the accuracy of analytical values reported in the literature that were obtained by calibration against a single standard.  相似文献   

High resolution Th_ex stratigraphy of sediments from high-latitude areas (Norwegian Sea, Fram Strait)     

Jan C. Scholten  Reiner Botz  Augusto Mangini  Hanno Paetsch  Peter Stoffers  Elke Vogelsang 《Earth and Planetary Science Letters》1990,101(1)

We present data on the average sedimentation rates (ranging from 1.6 cm/kyr to 3 cm/kyr) for the last 300.000 years based on δ¹⁸O analyses of foraminifera in a core from the Norwegian Sea and ²³⁰Th_ex measurements in cores from the Norwegian Sea and the Fram Strait (Arctic Ocean). Furthermore, we relate ²³⁰Th_ex variations downcore to the various oxygen isotope stages. This correlation is tentatively interpreted as being a result of the paleoceanographic and paleoclimatic control of bioproductivity. It is shown that based on the average sedimentation rates and characteristic ²³⁰Th_ex variations carbonate-poor sediment cores from northern latitudes can be correlated.  相似文献   

Stef Proost and John B. Braden (eds.), Climate Change, Transport and Environmental Policy     

David Reiner  Andreas Schafer 《Climatic change》2000,47(1-2):217-224

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Fluid Inclusions and Stable Isotopic Characteristics of the Yaoling Tungsten Deposit in South China: Metallogenetic Constraints     

Feng Yang  Wei Zhai  Xiaoming Sun  Reiner Klemd  Yanyan Sun  Yunshan Wu  Renmin Hua  Siqi Zheng 《Resource Geology》2019,69(1):107-122

The Yaoling tungsten deposit is a typical wolframite quartz vein‐type tungsten deposit in the South China metallogenic province. The wolframite‐bearing quartz veins mainly occur in Cambrian to Ordovician host rocks or in Mesozoic granitic rocks and are controlled by the west‐north‐west trending extensional faults. The ore mineralization mainly comprises wolframite and variable amounts of molybdenite, chalcopyrite, pyrite, fluorite, and tourmaline. Hydrothermal alteration is well developed at the Yaoling tungsten deposit, including greisenization, silicification, fluoritization, and tourmalinization. Three types of primary/pseudosecondary fluid inclusions have been identified in vein quartz, which is intimately intergrown with wolframite. These include two‐phase liquid‐rich aqueous inclusions (type I), two‐ or three‐phase CO₂‐rich inclusions (type II), and type III daughter mineral‐bearing multiphase high‐salinity aqueous inclusions. Microthermometric measurements reveal consistent moderate homogenization temperatures (peak values from 200 to 280°C), and low to high salinities (1.3–39 wt % NaCl equiv.) for the type I, type II, and type III inclusions, where the CO₂‐rich type II inclusions display trace amounts of CH₄ and N₂. The ore‐forming fluids are far more saline than those of other tungsten deposits reported in South China. The estimated maximum trapping pressure of the ore‐forming fluids is about 1230–1760 bar, corresponding to a lithostatic depth of 4.0–5.8 km. The δD_H2O isotopic compositions of the inclusion fluid ranges from ?66.7 to ?47.8‰, with δ¹⁸O_H2O values between 1.63 and 4.17‰, δ¹³C values of ?6.5–0.8‰, and δ³⁴S values between ?1.98 and 1.92‰, with an average of ?0.07‰. The stable isotope data imply that the ore‐forming fluids of the Yaoling tungsten deposit were mainly derived from crustal magmatic fluids with some involvement of meteoric water. Fluid immiscibility and fluid–rock interaction are thought to have been the main mechanisms for tungsten precipitation at Yaoling.  相似文献   

Moisture expansion as a deterioration factor for sandstone used in buildings   总被引：2，自引：1，他引：1  

Joerg Ruedrich  Tobias Bartelsen  Reiner Dohrmann  Siegfried Siegesmund 《Environmental Earth Sciences》2011,63(7-8):1545-1564

The expansion processes that develop in building stones upon changes of moisture content may be an important contributing factor for their deteriorations. Until recently, few data could be found in the literature concerning this parameter and weathering processes. Moreover, the processes that may be responsible for the moisture related expansion of natural building stones are not yet completely understood. To further elucidate this process, extensive mineralogical, petrophysical and fabric investigations were performed on eight German sandstones in order to obtain more information regarding the weathering process and its dependence on the rock fabric. The analysed sandstones show a wide range of pore size distributions and porosities. A positive correlation with the fabric and the pore space can be found for all studied petrophysical parameters. The intensity of the expansion and related swelling pressure cannot be attributed only to the swelling of clay minerals. The investigations suggest that the micropores and the resulting disjoining pressure during wet/dry cycles also play an important role. The results obtained suggest that the mechanism is related to the presence of liquid water within the porous material.  相似文献   

On the computation of the geoid–quasigeoid separation     

Jakob Flury  Reiner Rummel 《Journal of Geodesy》2011,85(3):185-186

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Moisture expansion associated to secondary porosity: an example of the Loseros Tuff of Guanajuato, Mexico   总被引：2，自引：2，他引：0  

Rubén López-Doncel  Wanja Wedekind  Reiner Dohrmann  Siegfried Siegesmund 《Environmental Earth Sciences》2013,69(4):1189-1201

The old mining city of Guanajuato in middle Mexico preserves one of the most important historical legacies in colonial buildings, the UNESCO declared the city World Heritage Site in 1988. Practically all the colonial constructions were built with natural stones from the neighbourhood, of which stands a greenish to reddish vulcanite, called Loseros Tuff. Although the Loseros Tuff is widely used in historical buildings in the city. It shows significant deterioration and weathering effects, principally in the parts where the tuff shows a coarse grain size. The petrographic, petrophysical, mineralogical and geochemical properties of the Loseros Tuff were analysed in order to determine the causes, effects, behaviour and response to deterioration of this volcanic rock. The results of the investigations suggest that in addition to the parameters like the grain size and the porosity properties, the pore radii distribution is decisive for the effectiveness of porosity and the water transport into the rock. It is recognized that once the liquid water invades the rock the dissolution of the matrix occurs, which is accompanied by a sudden moisture expansion favoured by the newly formed secondary porosity and the high content of expandable clay minerals.  相似文献