Search

Results:

Vol. 15 (2012 year), No. 2

Zhamaletdinov A.A.
Electron-conductive sulfide- and carbon-bearing structures in the continental Earth's crust ("SC layer by Semenov")

The paper highlights the nature of electron-conductive graphite- and sulfide-bearing anomalies called "SC layer by Semenov" in honor of inventor of this phenomenon – professor of Saint Petersburg University Alexander Sergeevich Semenov. The electrical conductivity of the Earth solid crystalline cover called the lithosphere is determined by two factors to follow: the vertical change of the fluid regime, composition and thermodynamic state of rocks with depth and the horizontal heterogeneity caused by the "crustal" conductivity anomalies of electron-conductive nature mostly. Crustal anomalies strongly affect results of the deep soundings. The formal 1D interpretation presents these as "fictive" intermediate conductive layers at the depth of from a few up to tens of kilometres. Investigations on shields provide a more detailed analysis of their structure, geological position, and value at forecasting mineral resources.

(in English, стр.12, fig. 7, tables. 1, ref 29, Adobe PDF, Adobe PDF 0 Kb)

Vol. 15 (2012 year), No. 2

Zhamaletdinov A.A.
A new model of the Earth crust structure from results of the control source electromagnetic soundings

It is suggested to subdivide the Earth's crust into two parts – upper, brittle crust (namely geological) and lower, ductile crust (namely physical). The upper crust of 10-15 km thickness is the most actively involved in geological processes. Its principal peculiarities are: the sharp horizontal heterogeneity of electrical properties, a wide range of variations of specific electrical resistivity from 1 to 105 Ohm·m, a high porosity, brittleness, and a presence of fluids that drain the supra structure from the day surface owing to penetrate of meteoric waters to the depths up to 5-10 km. The lower crust (physical) belongs to the depth interval from 10-15 to 35-45 km (up to the Moho boundary). It is remarkable by the horizontal homogeneity of electrical properties and high specific electrical resistivity in the range of 105-106 Ohm·m, by the low porosity and increased ductility. Electrical conductivity of the lower crust is mostly determined by the influence of planetary physical-chemical parameters (pressure, temperature, viscosity), phase transitions of substances and geodynamic peculiarities of evolution for different segments of the Earth crust. As an area of physical processes influence, the low crust is nearer by its origin to the Upper mantle then to the geological Upper Earth crust.

(in English, стр.5, fig. 1, tables. 0, ref 18, Adobe PDF, Adobe PDF 0 Kb)