Struktur des Alpenrandes zwischen Inn und Bodensee im Satellitenbild     

Dr. Bernd Lammerer 《International Journal of Earth Sciences》1976,65(1):525-535

1. Multispectral scanning imageries, revealed from ERTS-1 satellite, show a young lineament pattern in the region of the Northern Calcareous Alps. The statistical distribution of the lineament directions accords well with that of mapped faults. On the other hand, many of these lineaments are not mapped as faults. A more complex type of fracture is supposed for them, composed of many joints and minor faults. With increasing length of the fracture, the acute angle of the shear system increases from about 40° at joints to 70° at faults and 80° at lineaments.
2. The satellite imagery shows a relationship between the structures of the folded molasse and the alpine nappes. The mimer and depth of folds, the width of the folded zone, and the lateral limitation of the synclines are related to the amount of thrusting of parts of the nappe system. A model for the genesis of the folded molasse is given.

  相似文献   

Magnitude determination based on short-period core waves     

Jaromír Janský  Libuše Ruprechtová  Bernd Tittel  Reviewer K. Pěč 《Studia Geophysica et Geodaetica》1977,21(3-4):267-273

Summary PKP-amplitudes of about 400 earthquakes from the SW Pacific Ocean observed at three stations in Central Europe were used to obtain the calibration function q_PKP(D, h) based on the NEIS m_b magnitudes. The calibration function allows us to determine the magnitudes for week earthquakes from the Pacific, for which the magnitudes from the P-waves cannot be derived.  相似文献   

A Precambrian core sample from the Altiplano/Bolivia     

Bernd Lehmann 《International Journal of Earth Sciences》1978,67(1):270-278

Drilling in the Bolivian Altiplano discovered the Precambrian basement at 2.744 m of depth, Paleozoic strata lacking. The core is composed of hornblende meta-granite (hornblende granoblastite), in the upper part of biotite meta-granite (biotite granoblastite). Radiometric dating provides evidence for a Grenvillian magmatic or anatectic rock formation (1.050±100 my) and a later metamorphic event of 530±30 my in age.

---

Zusammenfassung In einem Bohraufschluß vom Altiplano in Bolivien wurde in 2.744 m Teufe unter tertiärer und kretazischer Bedeckung das präkambrische Basement angetroffen. Der präkambrische Bohrkern besteht teils aus Hornblende-Meta-Granit (Hornblende-Kalifeldspat-Quarz-Plagioklas-Gneis), teils aus Biotit-Meta-Granit (Biotit-Kalifeldspat-Quarz-Plagioklas-Gneis). Nach Rb-Sr Datierung dürfte das Bildungsalter etwa 1.050±100 my betragen, eine Aufheizungsperiode um 530±30 my ist nach K-Ar Analyse zu vermuten.

---

Résumé Lors d'un forage dans l'Altiplano bolivien le substratum précambrien a été rencontré à une profondeur de 2.744 m. La couverture sédimentaire comprend des couches tertiaires et crétaciques. La carotte précambrienne se compose d'un micro-granite gneissique de l'assemblage hornblende — feldspath potassique — quartz — plagioclase et d'un microgranite gneissique de biotite — feldspath potassique — quartz — plagioclase. L'âge de constitution de la roche est d'après l'analyse Rb-Sr de 1.050 ± 100 my. L'analyse K-Ar laisse supposer une transformation métamorphique de 530 ± 30 my.

---

- , 2744 . — ( - -- —, - (- -- -). - 1050 ± 100 , , - , 530 ± 30 .

  相似文献   

A framework for evaluating potential ecological effects of implementing biological control of<Emphasis Type="Italic">Phragmites australis</Emphasis>     

Bernd?BlosseyEmail author 《Estuaries and Coasts》2003,26(2):607-617

The increasing abundance ofPhragmites australis in many North American coastal and inland wetlands is of great concern to many scientists and land managers. While some considered the species native, others considered it an introduced invasive species. Regardless of its origin, control measures using mechanical, physical, and chemical means are implemented widely. With the exception of increased salinity, reductions in the abundance ofP. australis are usually temporary and control measures need to be repeated frequently increasing the cost and the potential for nontarget effects. The failure of traditional control attempts resulted in increased interest to develop a biological control program. Recent research suggests that genetically distinct populations (introduced and native) occur in North America. The native genotypes appear noninvasive and declining while the introduced genotypes are invasive replacing native genotypes where they co-occur. Accidentally introduced European herbivores specialized onP. australis are spreading across North America and can be extremely abundant in the Northeast. Introduction of additional specialized herbivores as biological control agents from the European range ofP. australis, if approved and successful, will result in changes in plant communities, wetland food webs, and management practices. The potential changes associated with introduction of biological control agents to wetland plant communities and their food webs may be more beneficial than current management strategies allowing the introducedP. australis genotypes and its associated herbivores to spread.  相似文献   

International Earth Rotation and Reference Systems Service (IERS) web: www.iers.org     

Jan Vondrák  Bernd Richter 《Journal of Geodesy》2004,77(10-11):585-678

  相似文献   

The geochemical cycle of boron: Constraints from boron isotope partitioning experiments between mica and fluid   总被引：8，自引：0，他引：8  

Bernd Wunder  Anette Meixner  Rolf L. Romer  Richard Wirth  Wilhelm Heinrich 《Lithos》2005,84(3-4):206-216

The fractionation of boron isotopes between synthetic boromuscovite and fluid was experimentally determined at 3.0 GPa/500 °C and 3.0 GPa/700 °C. For near-neutral fluids Δ¹¹B_(mica-fluid) = δ¹¹B_(mica) − δ¹¹B_(fluid) is − 10.9 ± 1.3‰ at 500 °C, and − 6.5 ± 0.4‰ at 700 °C. This supports earlier assumptions that the main fractionation effect is due to the change from trigonal coordination of boron in neutral fluids to tetrahedrally coordinated boron in micas, clays and melts. The T-dependence of this effect is approximated by the equation Δ¹¹B_{(mica,clay,melt–neutral fluid)} = − 10.69 · (1000/T [K]) + 3.88; R² = 0.992, valid from 25 °C for fluid–clay up to about 1000 °C for fluid–silicate melt. Experiments at 0.4 GPa that used strongly basic fluids produced significantly lower fractionations with Δ¹¹B_{(mica–fluid)} of − 7.4 ± 1.0‰ at 400 °C, and − 4.8 ± 1.0‰ at 500 °C, showing the reduced fractionation effect when large amounts of boron in basic fluids are tetrahedrally coordinated. Field studies have shown that boron concentrations and ¹¹B/¹⁰B-ratios in volcanic arcs systematically decrease across the arc with increasing distance from the trench, thus reflecting the thermal structure of the subducting slab. Our experiments show that the boron isotopic signature in volcanic arcs probably results from continuous dehydration of micas along a distinct P–T range. Continuous slab dehydration and boron transport via fluid into the mantle wedge is responsible for the boron isotopic signature in volcanic arcs.  相似文献   

中德联合冬给措纳湖地区寒区环境变迁研究进展     

杨思忠  金会军  Bernd Wünnemann  Steffen Mischke  吉延峻  陈建辉  杨奇丽 《冰川冻土》2006,28(6):850-853

青藏高原腹地的内陆湖及其湖相沉积物能够较真实地反映气候变化特征,在高原环境变迁研究中备受中外科学家的关注.2006年8月15日~9月10日,中德联合考察小组对青藏高原东北部的冬给措纳湖一带进行了第四纪冻土、地貌和地质学考察,并对湖岸阶地做了初步的数字高程分析.调查了冬给措纳湖底地形、地貌,采集了湖相沉积物样本.在湖的东岸和西岸发现多年冻土,湖泊西北山谷观察到古冰川活动遗迹.初步推测该湖是由断陷沉降形成.为进一步分析湖区气候和环境变迁,联合小组拟定2007年3月份钻取湖芯.  相似文献   

Equilibrium experiments in the system MgO–SiO2–H2O (MSH): stability fields of clinohumite-OH [Mg9Si4O16(OH)2], chondrodite-OH [Mg5Si2O8(OH)2] and phase A (Mg7Si2O8(OH)6)     

Bernd Wunder 《Contributions to Mineralogy and Petrology》1998,132(2):111-120

The water-pressure and temperature stability fields of clinohumite-OH, chondrodite-OH and phase A were determined in reversed equilibrium experiments up to 100 kbar within the system MgO–SiO₂–H₂O. Their PT-fields differ from results from former synthesis experiments. Bracketing experiments on the reaction phase A + low P-clinoenstatite ⇆ forsterite + water resulted in a slightly steeper dP/dT-slope compared to earlier experiments for this equilibrium. Clinohumite-OH and chondrodite-OH both have large stability fields which extend over pressure ranges of more than 80 kbar. However, they are hardly relevant as hydrous minerals within the subducted oceanic lithosphere. Both are too Mg-rich for a typical mantle bulk composition. In addition, the dehydration of subducted oceanic lithosphere – due to (forsterite + water)-forming reactions – will occur before the two humite-group phases even become stable. Restricted to the cool region of cold subducting slabs, phase A, however, might be formed via the reactions phase A + low P-/high P-clinoenstatite ⇆ forsterite + water or antigorite + brucite ⇆ phase A + water, before dehydration of the oceanic lithosphere occurs. Received: 22 July 1997 / Accepted: 12 March 1998  相似文献   

Late 20th century climatic change over the northern hemisphere and its consequences for numerical weather prediction     

Bernd Kuemmel 《Climatic change》1996,32(4):379-385

  相似文献   

Effects of prolonged darkness on the relative pigment content of cultured diatoms and green algae     

Bernd Deventer  Charles W. Heckman 《Aquatic Sciences - Research Across Boundaries》1996,58(3):241-252

To determine some of the environmental effects that influence the relative proportions of pigments in algae, high pressure liquid chromatographic (HPLC) analysis was employed to determine the relative amounts of common photosynthetic pigments in batch cultures of the diatoms,Fragilaria crotonensis andThalassiosira pseudonana, and the green algae,Scenedesmus abundans, andHaematococcus pluvialis, illuminated for 12 hours each day. Similar analyses were conducted in five-day experiments during which cultures ofF. crotonensis andS. quadricauda were kept in continuous darkness. Comparing the results to those for controls continuing to receive the daily illumination indicated that the diatoms and green algae react similarly to light deficiency. The relative amounts of the main accessory pigment in the diatoms, fucoxanthin, and that in the green alga, apparently lutein, decreased as a reaction to a lack of illumination, while the total chlorophyll level in algae of both groups remained nearly constant. Quantitative differences induced by the experimental conditions were considerably less that those observed among different species of diatom or among the different green algae, however. Finally, cultures ofS. quadricauda were analyzed and then kept for 43 days without the addition of any nutrients. A proportion of the culture was kept for this period in perpetual darkness while another continued to receive 12 hours of illumination. The results show that considerable changes occur as the cultures age, and that these changes occur more slowly in the darkness. Some consequences of these findings for phytoplankton production studies based on analyses of photosynthetic pigments are discussed.  相似文献