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91.
Holocene sedimentation in the Strait of Otranto between the Adriatic and Ionian Seas (Mediterranean)
An extensive radiograph study of 24 undisturbed, up to 206-cm long box and gravity cores from the western part of the Strait of Otranto revealed a great variety of primary bedding structures and secondary burrowing features. 相似文献
92.
It is shown that the proof of the g = o theorem established by KHALATNIKOV and LIFSHITZ in general relativity has to be supplemented by additional considerations. The same investigations are made for TREDER'S tetrad theory of gravitation. 相似文献
93.
Meredith A. Kelly Peter W. Kubik Friedhelm Von Blanckenburg Christian SchlÜchter 《第四纪科学杂志》2004,19(5):431-441
Egesen moraines throughout the Alps mark a glacial advance that has been correlated with the Younger Dryas cold period. Using the surface exposure dating method, in particular the measurement of the cosmogenic nuclide 10Be in rock surfaces, we attained four ages for boulders on a prominent Egesen moraine of Great Aletsch Glacier, in the western Swiss Alps. The 10Be dates range from 10 460±1100 to 9040±1020 yr ago. Three 10Be dates between 9630±810 and 9040±1020 yr ago are based upon samples from the surfaces of granite boulders. Two 10Be dates, 10 460±1100 and 9910±970 yr ago, are based upon a sample from a quartz vein at the surface of a schist boulder. In consideration of the numerous factors that can influence apparently young 10Be dates and the scatter within the data, we interpret the weighted mean of four boulder ages, 9640±430 yr (including the weighted mean of two 10Be dates of the quartz vein), as a minimum age of deposition of the moraine. All 10Be dates from the Great Aletsch Glacier Egesen moraine are consistent with radiocarbon dates of nearby bog‐bottom organic sediments, which provide minimum ages of deglaciation from the moraine. The 10Be dates from boulders on the Great Aletsch Glacier Egesen moraine also are similar to 10Be dates from Egesen moraines of Vadret Lagrev Glacier on Julier Pass, in the eastern Swiss Alps. Both the morphology of the Great Aletsch Glacier Egesen moraine and the comparison with 10Be dates from the inner Vadret Lagrev Egesen moraine support the hypothesis that the climatic cooling that occurred during the Younger Dryas cold episode influenced the glacial advance that deposited the Great Aletsch Glacier Egesen moraine. Because of the large size and slow response time of Great Aletsch Glacier, we suggest that the Great Aletsch Glacier Egesen moraine was formed during the last glacial advance of the multiphased Egesen cold period, the Kromer stage, during the Preboreal chron. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
94.
95.
Roger N. Anderson Michael A. Hobart R. P. Von Herzen Daniel J. Fomari 《Geophysical Journal International》1978,54(1):141-166
Summary. The East Pacific Rise at 12–15° S is topographically smooth with a crestal horst or linear volcanic peak marking the present axis of spreading. The Galapagos Rise at 14–17° S is topographically rough with a possible central graben marking the extinct spreading axis. The seafloor spreading magnetic anomalies on the East Pacific Rise are of low amplitude, but fracture-zone anomalies at 13–14° S have amplitudes of up to 1250 nT. Anomalies of this amplitude at the magnetic equator must be formed within the fracture zone by some combination of block reversal boundaries, anomalously-high magnetic intensities, and/or anomalously-large thicknesses of the magnetic layers within the fracture zone. Magnetization and major-element chemical analyses of basalts dredged from four locales along the fracture zone indicate that the large magnetic-anomaly amplitudes are caused by the high iron and titanium content of these ferrobasalts. The magnetic-anomaly profiles from the Galapagos Rise and its fracture-zone system are of normal amplitude and are extremely difficult to correlate internally or with the geomagnetic timescale.
Eighty-one heat-flow measurements indicate that the values measured are controlled by sediment thickness. Where the thickness of the sediment blanket is greater than 100 m, high heat flow is measured and possibly is representative of the total heat transfer at the seafloor. Where the sediment thickness is less than 100 m, seawater circulation in the oceanic crust is thought to remove most of the heat convectively; thus causing low conductive heat-flow values to be measured by the usual heat-flow apparatus. The heat loss by convective processes is probably a function also of topographic roughness and sediment permeability. 相似文献
Eighty-one heat-flow measurements indicate that the values measured are controlled by sediment thickness. Where the thickness of the sediment blanket is greater than 100 m, high heat flow is measured and possibly is representative of the total heat transfer at the seafloor. Where the sediment thickness is less than 100 m, seawater circulation in the oceanic crust is thought to remove most of the heat convectively; thus causing low conductive heat-flow values to be measured by the usual heat-flow apparatus. The heat loss by convective processes is probably a function also of topographic roughness and sediment permeability. 相似文献
96.
Highly resolved H spectra and filtergrams obtained at the Fraunhofer Observatory on Capri were analysed by a method whose principles have been described before. As a result the tentative conclusion of our previous work has been confirmed: The mottles of the chromospheric fine structure are clouds superimposed on the low chromosphere. Furthermore, it is proposed that the latter is identical with the interior of the supergranular cells whose spatial averages lend themselves to an interpretation in terms of a spherically symmetric model. On the other hand, we present evidence that the boundary regions which are formed by the mottles of the fine structure pattern and which constitute the upper chromosphere are not adequately described by spatial averages. Instead, the properties of the individual structural elements should be taken into account by an appropriate theory, if only in a statistical fashion. Some of these properties, viz. source function, optical thickness, Doppler width and velocity, were measured for a large number of elements. On the basis of indirect evidence we suggest that the spicules seen on limb photographs of chromospheric lines are identical with the elements of the supergranule boundary structure.Mitteilung aus dem Fraunhofer Institut Nr. 116. 相似文献
97.
Measurements of the energy spectra of carbon and oxygen nuclei in the primary cosmic radiation over the energy range from 140 MeV/nuc to 30 BeV/nuc are reported. An average C/O ratio of 1.11±0.02 is obtained at the top of the atmosphere. This ratio is found to be constant to within 5% over the entire energy range. The energy spectra of these two nuclei are presented and compared with earlier measurements and with satellite observations at low energies. After correction for propagational effects in 4 g/cm2 of interstellar hydrogen the source C/O ratio is found to be 0.9. The astrophysical implications of this C/O ratio are discussed. 相似文献
98.
99.
H. R. Von Gaertner 《International Journal of Earth Sciences》1958,47(1):72-73
Ohne Zusammenfassung 相似文献
100.
Wolf Von Engelhardt 《International Journal of Earth Sciences》1955,43(2):568-572
Zusammenfassung Es werden die allgemeinen Bedingungen diskutiert, die erfüllt sein müssen, um aus der Intensität von Röntgenlinien die Mineralzusammensetzung von feinen Pulvern zu bestimmen. Im Hinblick auf die Analyse von Tonen werden die bei den einzelnen Tonmineralgruppen auftretenden besonderen Schwierigkeiten besprochen. 相似文献