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991.
Deformation properties of the lithosphere derived from data on recent crustal movements of the earth
aamuam a¶rt;aa ¶rt;uu ¶rt; m u¶rt;mu, uau n¶rt; uu mua ¶rt;uu a uau u . a auu au mmuu mam ¶rt;au mua ¶rt;uu ¶rt;am m am ¶rt; ¶rt;au ma um. 相似文献
992.
Summary It is shown that non-divergent vortices may induce, as a result of the resonance effect, a rapid surface development. 相似文献
993.
Dry ore dust pollution decreased the hatching success of fowl eggs from 76% in the control to 57% when manganese ore dust and 54% when iron ore dust were used. Daily wetting of eggs aggravated the ore dust effect. When eggs were covered with ore dust, the heat exchange properties of eggs exposed to direct sunlight were significantly changed. Manganese and iron ore dust covered eggs heated and cooled at a significantly faster rates than the controls. The interior uppermost area may reach a temperature of 54°C after 60 minutes in the sun. Manganese ore dust covered brown eggs were the most affected and white eggs the least. Ore dust pollution therefore poses a threat to the hatching success of bird eggs. 相似文献
994.
D.P. Thompson A.R. Basu E.W. Hennecke O.K. Manuel 《Physics of the Earth and Planetary Interiors》1978,17(2):98-107
The abundances and isotopic compositions of noble gases in two samples from ultramafic xenoliths in alkali basalt, a young kaersutitic amphibole separated from a peridotite xenolith from Dish Hill, California and an ancient whole-rock lherzolite xenolith from Baja California, are reported and compared with the results of analyses on other mantle samples. In addition to previously recognized excesses of 3He and 129Xe, our results indicate that ambient gases in the mantle show a general enrichment of the lighter-mass nonradiogenic isotopes of Ar, Kr and Xe, and Ar with 40Ar/36Ar = 3 · 102. 相似文献
995.
T. O. Reimer 《Mineralium Deposita》1978,13(2):235-244
Beds of sedimentary barytes are found in late Paleozoic sediments in the northeasternmost part of South Africa and adjoining parts of Rhodesia. The baryte horizon consists of 2 beds of composite thickness of up to 50 cm within a sequence of partly porcellaneous shales. It is dark gray to redbrown in colour, in places also black, and then contains traces of H2S. It usually consists of fine-grained subrounded tabular grains of detrital origin. This horizon frequently contains aggregates of upward diverging acicular baryte which formed diagenetically within the detrital baryte. The deposit was formed through reworking of semiconsolidated clays containing baryte concretions. Such shales are known to occur to the west of the baryte deposit in contemporaneous sediments.
Zusammenfassung In spätpaläozoischen Sedimenten im Nordosten Südafrikas und dem angrenzenden Bereich Rhodesiens treten sedimentäre Barytlagen auf. Die Barytzone besteht aus zwei Lagen mit einer gemeinsamen größten Mächtigkeit von 50 cm, innerhalb einer Abfolge teilweise verkieselter Tonschiefer. Der Baryt ist dunkelgrau bis rotbraun, stellenweise auch schwarz, und enthält dann Spuren von H2S. Er besteht meist aus feinkörnigen kantengerundeten schwach plattigen Kristallen detritischer Herkunft. Die Zone enthält häufig Aggregate aus nach oben divergierenden nadeligen Barytkristallen, die sich frühdiagenetisch im detritischen Baryt bildeten. Das Vorkommen entstand durch Aufarbeitung von Barytkonkretionen in schwach verfestigten Tonen. Entsprechende Tonschiefer treten in gleichaltrigen Sedimenten westlich des Barytvorkommens auf.相似文献
996.
P. Ruggiero O. Sciacovelli C. Testini F.S. Interesse 《Geochimica et cosmochimica acta》1978,42(4):411-416
The IR and 1H-NMR spectra of fulvic acids (FA) are discussed. The FA, extracted by traditional methods, were fractionated on the basis of molecular weight (m.w.). Three fractions were obtained labelled FA I (m.w. > ~ 2000), FA II (m.w. > ~ 12000) and FA III (~2000 < m.w. < ~ 12000). Fraction FA II was methylated with CH3I-Ag2O. The 1H-NMR spectra of unmethylated FA fractions show some signals common to all three fractions and some differences in the 3–5 ppm range due to the resonances of OCH3 and O-CH2 groups. The proton spectrum of the methylated fraction shows absorption areas for OCH3 groups of phenols and carboxyls. The results confirm that NMR spectroscopy is a convenient technique which can contribute to defining the chemical structure of humic substances. 相似文献
997.
High-sensitivity experiments with particles that are strongly enriched in alpha-emitting nuclei show that damaged regions are produced that can be eroded by subsequent exposure to water. Direct ejection of recoil nuclei from solid grains is also observed. These observations appear to supply a basis for understanding disequilibria between 238U and 234U in natural samples that have been exposed to water. The two mechanisms observed are expected to act under different natural conditions. 相似文献
998.
999.
1000.
Taal Volcano is peculiar in its violent explosivity in spite of its low altitude. The surrounding topographies suggest that the origin of Taal Volcano is either a caldera or a graben structure. To confirm the caldera origin one must search for a vast quantity of caldera ejecta balancing with the depression. As a first step, a gravity survey was carried out on and around Taal Volcano, and high gravity anomalies were lound on Volcano Island. The distribution of the gravities may suggest a graben structure overlying a denser layer of igneous material. 相似文献