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1. Some properties and structure of the crystalline crust from superdeep drilling data (SG-3, SG-4, KTB)

Creator:
Gobratsevich, Felix F.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geofyzika, geodynamika, geophysics, geodynamics, anisotropy, crystalline crust, density, structure, rock properties, superdeep boreholes, velocity, 7, and 551
Language:
English
Description:
Among the programmes aimed at developing a standard model for properties and state of the Earth’s crystalline crust, those dealing with drilling the Kola (SG-3), Ural (SG-4) and German (KTB) superdeep boreholes yielded the most interesting results. No marked depth dependence of rock volume density and seismic wave velocities was observed in the sections of SG-3 and SG-4. A new result of the investigations is the discovery of strongly anisotropic rocks in the SG-3, SG-4 and KTB sections. In the massifs of the Kola and German superdeep boreholes such rocks constitute the majority of the drilled sections. The presence of the velocity anisotropy as well as the complex structure of the rocks composing crystalline metamorphosed sequences greatly hamper the interpretation of the results obtained from the seismic survey conducted at the surface., Felix F. Gobratsevich., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. Structure and permeability of deep-seated rocks in the kola superdeep borehole section (SG-3)

Creator:
Gorbatsevich, Felix F., Ikorsky, Serafim V., and Zharikov, Andrey V.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, propustnost materiálů, skály, helium, permeability, rocks, crystalline crust, anisotropy, structure, 7, and 551
Language:
English
Description:
Preferential flow paths in the crust, as caused by the presence of the Luchlompolo fault in the drilled section of the Kola Superdeep Borehole (SG-3) and the dip angle of the rock structural elements (layering, schistosity, banding), are favourable for migration of deep fluids to the Earth’s surface. An investigation of the structure, anisotropy and permeability of rocks under PT-conditions in the SG-3 section, in addition to the occurrence of He-isotopes, reveals that the high-permeability zones of the exposed crustal segment are related to two important structural elements of the section: in the upper zone - to the Luchlompolo fault, in the lower one to the contact between the Proterozoic and Archaean complexes. The obtained results on the rock samples from SG-3 indicate a rough correlation between permeability and elastic anisotropy of various rock samples. Simulating increased PT-conditions, corresponding to the relevant depths of 6-8 km document the overlapping temperature and pressure effect, i.e. resulting in a sharp decrease of rock permeability., Felix F. Gorbatsevich, Serafim V. Ikorsky and Andrey V. Zharikov., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public