ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    An Upper Carboniferous-Lower Permian (280 Ma) palaeomagnetic pole from the western margin of the Bohemian Massif (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 105 (1991), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: In the area of the drill site of the German Continental Deep Drilling Project KTB on the western margin of the Bohemian Massif 15 sites of Uppermost Carboniferous to Lowermost Permian rocks (quartz porphyries, granites and a siltstone, geographic mean coordinates: 12°E, 49.8°N) have been studied in order to obtain a reliable pole position for this time interval. The investigated rocks are syngenetic or only slightly younger than the youngest granites of the Fichtelgebirge for which a K/Ar and Rb/Sr age of 280 Ma has been determined by Besang et al. (1976). While four sites (quartz porphyries) showed too weak intensities of the natural remanent magnetization NRM, the results of two sites with otherwise good rock magnetic properties had to be discarded because of uncertain tectonic position in a shear zone. The remaining nine sites have all reversed polarity as expected for a remanence age within the reversed Kiaman interval and a mean pole position at 165.9°E, 42.3°N with N= 9, R= 8.8776, A95= 6.4°. This is in good agreement with the mean Upper Carboniferous-Lower Permian European pole position of Stable Europe according to Irving & Irving (1982) and of the Bohemian Massif (Krs 1968). Rock magnetic investigations revealed that the ChRM of the siltstone is due to primary magnetite, while the mostly single-component characteristic remanent magnetization ChRM of the magmatic rocks is carried by primary magnetite and by primary haematite produced by syngenetic high-temperature oxidation of primary magnetite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1991.tb06733.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Magnetic refraction studied on two experimental kilns (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 102 (1990), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: Two experimental kilns in the form of shells (half-spheres) and circular bottom plates (inner radius: 15 cm, outer radius 17 cm) were made from clay, fire-clay and less than 5 per cent by volume of fine grained haematite powder for the study of the effect of magnetic refraction in archaeological structures. The haematite in the clay was reduced to a strongly magnetic phase (maghematized magnetite). The acquisition of TRM was performed in a non-magnetic gas-heated furnace in the local geomagnetic field. The kiln material has a maghemite ore content of about 2 per cent by volume and an apparent magnetic susceptibility at room temperature of about 4 x 10-2 SI units. The deviations of the declination and inclination of the TRM at different‘latitudes’of the shells were, respectively, up to 40° and 15° and systematically dependent from the position of the specimens in the shell or bottom plate in agreement with model calculations. However, the classical approach for the magnetic refraction in materials with ferrimagnetic ore grains dispersed in a nonmagnetic rock matrix with simple assumptions for the demagnetizing fields of the ore grains and of the macroscopic sample was not able to explain the large refraction effects which have been observed. An adequate theory for the magnetic refraction in rocks is still not available.For archaeomagnetic studies, some advice is offered for sampling and demagnetization treatment of the material in order to minimize refraction effects in archaeomagnetic data. Some consequences for palaeomagnetic studies are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1990.tb04581.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The Sabaloka ring complex revisited: palaeomagnetism and rockmagnetism (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 102 (1990), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The isotopically dated Lower to Middle Devonian Sabaloka complex (16.3d̀N, 32.6d̀E) in Northern Sudan, for which a palaeomagnetic pole position close to the present geomagnetic pole had been derived in a previous investigation, has been revisited. The formerly determined direction of remanence is shown to be of secondary origin (possibly due to recent or Pleistocene weathering, as shown by ore microscopy and a negative conglomerate test) and a further component of magnetization is detected at several sites. Rockmagnetic studies give strong arguments in favour of a primary origin of the newly found remanence direction. In this paper the palaeomagnetic results (site means) of the two laboratories (Munich and Leeds) for the Sabaloka complex have been combined yielding D= 340.1d̀, I=- 43.9d̀, N= 15, k= 20.6, α95= 8.0d̀. This gives a palaeomagnetic South Pole position (site mean) at 42.0d̀S and 55.7d̀E which is discussed in the context of other Palaeozoic pole positions of Gondwana.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1990.tb04474.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Upper Proterozoic and Phanerozoic Pole Positions and Potassiumargon (K-Ar) Ages From the East Sahara Craton (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 97 (1989), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: Seven new palaeopole positions from southern Egypt and northern Sudan with ages ranging from Upper Proterozoic (720 Ma) to Uppermost Cretaceous are presented and discussed in the context of the apparent polar wander path (APWP) of Africa. Rockmagnetic studies were also performed to determine the carriers of magnetization and to test the reliability of the remanence data. Ages pertinent to the APWP were taken from the literature or-for most of the localities-have been determined by K-Ar dating on whole rocks or minerals. the localities, geographic coordinates, ages, rock types and positions of the palaeomagnetic South Poles are as follows:(1) Gebel Gifata, SW Egypt, 29.0°E, 25.5°N, Upper Cretaceous (65–70 Ma) limestones and shales, 45.0°E, 81.5°S. (2) Northern Volcanic Field, N Sudan, 33.3°E, 19.0°N, Upper Cretaceous (80 Ma) basalts, 97.8°E, 55.9°S. (3) Nusab el Balgum complex, SW Egypt, 29.3°E, 23.3°N, Triassic (216 Ma) rhyolites and subvolcanics, 50.7°E, 64.1°S. (4) Sabaloka complex, N Sudan, 32.6°E, 16.3°N, Lower Devonian (395 Ma) volcanics, subvolcanics, metamorphosed quartzite, 55.8°E, 43.5°S. (5) Bir Safsaf, SW Egypt, 29.3°E, 23.1°N, Cambrian (586 Ma) dykes, 249.7°E, 80.0°N. (6) Nabati, N Sudan, 33.7°E, 18.1°N, Pre-Cambrian-Lower Cambrian (589 Ma) diorite and granite, 314.1°E, 67.9°N. (7) Kadaweb, Red Sea Hills, N Sudan, 36.3°E, 20.1°N, Proterozoic (720 Ma) gabbros, 319.6°E, 1.0°N.Nine other localities of Mesozotc and Palaeozoic rocks gave no reliable pole positions, mostly due to secondary magnetizations. the seven palaeopoles cover the Phanerozoic and Upper Proterozoic and increase the palaeomagnetic database for Africa. For the Phanerozoic there is coincidence with the palaeomagnetic data of other African cratonic areas indicating that Africa has behaved as a more or less stable block since the end of the Pan-African orogeny.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1989.tb00497.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Physical parameters measured on cores and cuttings from the pilot well (0 m–4000.1 m) of the German continental deep drilling program (KTB) in the Oberfalz area, Bavaria, Federal Republic of Germany (1992)
    Springer
    Surveys in geophysics 13 (1992), S. 1-34 
    Details
    ISSN: 1573-0956
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The project of an ultradeep drill hole (KTB) in the Oberpfalz area at the western margin of the Bohemian Massif has completed a pilot drill hole to a depth of 4000.1 m in April 1989. This well is situated only about 200m away from the main drill hole aimed at 10 km depth where drilling started in September 1990. The cores of the pilot well have a diameter of 9.4 cm or 10.16 cm, respectively. In addition to cores and cuttings there was also mud available for geochemical, petrological and some geophysical measurements. The pilot drill hole has a core recovery length of as much as 3042.6 m (about 76%), among which 193.1 m were obtained by rotary drilling and 2849.5 m by wireline drilling. Several petrophysical parameters were measured in a specially established field laboratory at the drill site immediately after sampling in order to obtain as good as possible in-situ values. Results for the following parameters are reported: density, natural gamma ray activity, velocities of seismic longitudinal and shear waves, thermal conductivity, electrical resistivity, natural remanent magnetization, magnetic susceptibility, porosity and inner surface. The methods of measurement are characterized briefly and the results of the pilot drill hole are presented and discussed in connection with the lithology and the geophysical anomalies, which have been observed on the surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01901949
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    New palaeomagnetic data from Central Iran and a Triassic palaeoreconstruction (1996)
    Springer
    Geologische Rundschau 85 (1996), S. 293-302 
    Details
    ISSN: 0016-7835
    Keywords: Key words Iran ; palaeomagnetism ; Triassic ; Cretaceous ; Central Iran ; geotectonics ; palaeoreconstruction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  New pole positions for Triassic and Cretaceous times have been obtained from volcanic and sedimentary sequences in Central Iran. These new results confirm the general trend of the Apparent Polar Wander Path (APWP) of the Central-East-Iran microplate (CEIM) from the Triassic through the Tertiary as published by Soffel and Förster (1983, 1984). Two new palaeopoles for the Triassic of the CEIM have been obtained; limestones and tuffs from the Nakhlak region yield a mean direction of 094.0°/25.0°, N=12, k=4.1, α95=24.7°, after bedding correction, corresponding to a palaeopole position of 310.8°E; 3.9°S, and volcanic rocks from the Sirjan regions yield a mean direction of 114.5°/35.1°, N=44, k=45.9, α95=3.2° after bedding correction and a palaeopole position of 295.8°E; 10.3°N. Combining these with the two previously published results yields a new palaeopole position of 317.5°E; 12.7°N, for the Triassic of the CEIM, thus confirming that large counterclockwise rotations of the CEIM have occurred since the Triassic time. New results have also been obtained from Cretaceous limestones from the Saghand region of the CEIM. The mean direction of 340.7°/26.3°, N=33, k=44.3, α95=3.8°, and the corresponding palaeopole position of 283.1°E; 64.4°N, is in agreement with previously determined Cretaceous palaeopole positions of the CEIM. Furthermore, results have also been obtained from Triassic dolomite, limestone, sandstone and siltstone from the Natanz region, which is located to the west of the CEIM. A total of 161 specimens from 44 cores taken at five sites gave a mean direction of the five sites at 033.3°/25.1°, N= 5, k=69.0, α95=9.3° and a palaeopole position of 167.2°E; 53.7°N. They pass the positive fold test of McElhinny (1964) on the level of 99% confidence. This pole position is in fairly good agreement with the mean Triassic pole position of the Turan Plate (149°E; 49°N). It indicates that the area of Natanz has not undergone the large counterclockwise rotation relative to the Turan plate since the Triassic, which has been shown for the CEIM. A Triassic palaeogeographic reconstruction of Iran, Arabia (Gondwana) and the Turan Plate (Eurasia) is also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005310050075
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    New palaeomagnetic data from Central Iran and a Triassic palaeoreconstruction (1996)
    Springer
    International journal of earth sciences 85 (1996), S. 293-302 
    Details
    ISSN: 1437-3262
    Keywords: Iran ; palaeomagnetism ; Triassic ; Cretaceous ; Central Iran ; geotectonics ; palaeoreconstruction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract New pole positions for Triassic and Cretaceous times have been obtained from volcanic and sedimentary sequences in Central Iran. These new results confirm the general trend of the Apparent Polar Wander Path (APWP) of the Central-East-Iran microplate (CEIM) from the Triassic through the Tertiary as published by Soffel and Förster (1983, 1984). Two new palaeopoles for the Triassic of the CEIM have been obtained; limestones and tuffs from the Nakhlak region yield a mean direction of 094.0°/25.0°, N=12, k=4.1,α 95=24.7°, after bedding correction, corresponding to a palaeopole position of 310.8°E; 3.9°S, and volcanic rocks from the Sirjan regions yield a mean direction of 114.5°/35.1°, N=44, k=45.9,α 95=3.2° after bedding correction and a palaeopole position of 295.8°E; 10.3°N. Combining these with the two previously published results yields a new palaeopole position of 317.5°E; 12.7°N, for the Triassic of the CEIM, thus confirming that large counterclockwise rotations of the CEIM have occurred since the Triassic time. New results have also been obtained from Cretaceous limestones from the Saghand region of the CEIM. The mean direction of 340.7°/26.3°, N=33, k=44.3,α 95=3.8°, and the corresponding palaeopole position of 283.1°E; 64.4°N, is in agreement with previously determined Cretaceous palaeopole positions of the CEIM. Furthermore, results have also been obtained from Triassic dolomite, limestone, sandstone and siltstone from the Natanz region, which is located to the west of the CEIM. A total of 161 specimens from 44 cores taken at five sites gave a mean direction of the five sites at 033.3°/25.1°, N=5, k=69.0,α 95=9.3° and a palaeopole position of 167.2°E; 53.7°N. They pass the positive fold test of McElhinny (1964) on the level of 99% confidence. This pole position is in fairly good agreement with the mean Triassic pole position of the Turan Plate (149°E; 49°N). It indicates that the area of Natanz has not undergone the large counterclockwise rotation relative to the Turan plate since the Triassic, which has been shown for the CEIM. A Triassic palaeogeographic reconstruction of Iran, Arabia (Gondwana) and the Turan Plate (Eurasia) is also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02422235
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    150 years of magnetic observatories: Recent researches on world data (1992)
    Springer
    Surveys in geophysics 13 (1992), S. 47-88 
    Details
    ISSN: 1573-0956
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract A joint Discussion Meeting of the Royal Astronomical Society and the Royal Irish Academy, held on January 11th, 1991, commemorated the establishment of some early magnetic observatories, discussed recent research using global geomagnetic data and described the present status of magnetic observatories in the United Kingdom. The observatory and instruments at the Dublin magnetic observatory; the origins of the Greenwich magnetic observatory, and why it eventually had to be resited; and the history of the Munich magnetic observatory formed the historical part of the proceedings. Current research topics discussed were the geomagnetic secular variation and deep Earth structure and dynamics; fluid flow patterns near the top of the core; the origin of the annual variation of the geomagnetic field; results of an analysis of monthly means from some British observatories; a new theory of the geomagnetic daily variation; and the interactions between ionospheric science and geomagnetism. The present-day observatory scene was described in terms of the information that can be derived from the almost 40 year series of data from Hartland magnetic observatory; of the methods used to process data from the three UK magnetic observatories, which nowadays are operated automatically and remotely; and (a look into the future) of a new project, INTERMAGNET, which aims to make available, in near real time, data from the world-wide network of magnetic observatories.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01901951
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Geodynamic evolution of the European Variscan fold belt: palaeomagnetic and geological constraints (1997)
    Springer
    Geologische Rundschau 86 (1997), S. 585-598 
    Details
    ISSN: 0016-7835
    Keywords: Key words Variscan fold belt ; Armorica ; Avalonia ; Palaeomagnetism ; Palaeogeography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  The Variscan fold belt of Europe resulted from the collision of Africa, Baltica, Laurentia and the intervening microplates in early Paleozoic times. Over the past few years, many geological, palaeobiogeographic and palaeomagnetic studies have led to significant improvements in our understanding of this orogenic belt. Whereas it is now fairly well established that Avalonia drifted from the northern margin of Gondwana in Early Ordovician times and collided with Baltica in the late Ordovician/early Silurian, the nature of the Gondwana derived Armorican microplate is more enigmatic. Geological and new palaeomagnetic data suggest Armorica comprises an assemblage of terranes or microblocks. Palaeobiogeographic data indicate that these terranes had similar drift histories, and the Rheic Ocean separating Avalonia from the Armorican Terrane Assemblage closed in late Silurian/early Devonian times. An early to mid Devonian phase of extensional tectonics along this suture zone resulted in formation of the relatively narrow Rhenohercynian basin which closed progressively between the late Devonian and early Carboniferous. In this contribution, we review the constraints provided by palaeomagnetic data, compare these with geological and palaeobiogeographic evidence, and present a sequence of palaeogeographic reconstructions for these circum-Atlantic plates and microplates from Ordovician through to Devonian times.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005310050165
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Gravity anomalies in the KTB area and their structural interpretation with special regard to the granites of the northern Oberpfalz (Germany) (1997)
    Springer
    Geologische Rundschau 86 (1997), S. S79 
    Details
    ISSN: 0016-7835
    Keywords: Key words Bouguer map ; Crustal structure ; Vertical gradient map ; Depth estimation ; 3D forward modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  By fieldwork within the frame of the KTB project a new set of 1800 gravity data has become available. Prominent Bouguer anomalies are produced by the ZEV (high with −6 mGal), the Grafenwöhr block (low with −24 mGal) and the granites (low with −46 mGal). The vertical gradient map gives information about the near-surface structure. In addition, spectral analysis and upward continuation of the field data give information about depth extension of the granites and other units. The density structure of the crust is outlined by 3D interactive forward modeling. Regional anomalies are caused by the Erbendorf body and the dipping Moho. Local and dominating anomalies have different sources: (a) the foreland sediments with an underlying deep structure (possibly of ZEV material); (b) the ZEV metamorphic units (gneisses and metabasites); and (c) the granites. The ZEV units are controled by the steeply inclined SE1 reflector as a tectonic element. The Falkenberg granite provides two thirds of the total granitic volume and its depth reaches 6.5 km, whereas other granites reach depths of 2–3 km. The nature of the crustal material below the granites and of the Erbendorf body remains unknown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00014667
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...