共查询到20条相似文献,搜索用时 31 毫秒
1.
Izvestiya, Physics of the Solid Earth - Abstract—In my comment on the paper by A.A. Lyubushin, G.N. Kopylova, and Yu.K. Serafimova, I focus on the problem of legitimacy of seismological data... 相似文献
2.
Izvestiya, Physics of the Solid Earth - 相似文献
3.
4.
5.
V. F. Belyi 《Journal of Volcanology and Seismology》2010,4(3):149-163
A detailed petrographic study of the impactites found in the El’gygytgyn depression suggested a division of those into the
dacite-rhyolite (dominant) and the andesite-basalt (about 1% of the total impactite volume) groups. The protolith for the
dacite-rhyolite group was the Cretaceous ignimbrite rock association of the Okhotsk-Chukchi volcanic belt (OChVB), from which
the depth of their origin is estimated as 1–1.5 km. The impactites of the andesite-basalt group, which are generally older,
formed from protoliths of apparently metamorphic and magmatic complexes in the OChVB basement occurring at depths of 6.5–8.5
km. The hypothesis that the depths of origin for these groups are different is supported by certain features of clinopyroxene
composition. Geochemical relationships are found to exist between deep and shallow impactites, as shown in the distribution
of Ni, Cr, and Co. The succession of development for the shallow impactite generation forms the following series: impact ignimbrite
→ pumice → cinder → massive glass. The glasses have the most homogeneous overall chemical composition, but these too are characterized
by a high inhomogeneity in the composition of the vitric phases, indicating a rapid and discrete impactite generation that
impeded melt homogenization. The glasses are the final product of impactite generation; they show a dramatic drop in fluid
content and the associated reducing components. 相似文献
6.
7.
Studia Geophysica et Geodaetica - 相似文献
8.
9.
10.
V. V. Shcherbakova G. V. Zhidkov V. P. Shcherbakov 《Izvestiya Physics of the Solid Earth》2008,44(10):816-821
A large volume of data on the paleointensity H an obtained by A.S. Bol’shakov and G.M. Solodovnikov is ignored in modern reconstructions because the authors did not indicate whether they used the check-point procedure for the detection of chemical alterations in rocks associated with determination of H an. The paper presents new values of H an determined by the Thellier-Coe method with the use of the checkpoint procedure from samples of the Armenian collection of Cretaceous rocks used in published studies of Bol’shakov and Solodovnikov. The new results are close to the published ones and point to a small value of the geomagnetic field in the Cretaceous, thereby corroborating Bol’shakov-Solodovnikov’s hypothesis on a low paleofield in the Mesozoic. Our study of samples of the collection studied confirms the reliability of Bol’shakov-Solodovnikov’s determinations of H an. 相似文献
11.
12.
13.
14.
15.
16.
17.
18.