Electroconducting Elements of the Ultradeep Fluid–Fault Systems as Indicators of Seismically Active Zones of the Eastern Margin of the Eurasian Continent: Evidence from Magnetotelluric Data

Doklady Earth Sciences - A fundamentally new conclusion that zones of high seismic activity are controlled by electroconducting (fluid-saturated) fragments rather than by the entire deep fault is...     

Peculiarities of the fluid regime in the lithosphere of the junction zone between South Primorye and the Sea of Japan from the comprehensive geophysical data

New data on the fluid lithospheric regime in the junction zone of the continent and the marginal seas are presented. For the first time, this problem was solved by the comprehensive interpretation of the geophysical methods, including magnetotelluric and geomagnetic-variation sounding, unique investigations of the variations of the electric field along the Japan Sea Cable (JASC), structural-density modeling, thermometry, and thermodynamics. A joint analysis of the distribution of the electric conductivity, density, and temperature in the lithosphere made it possible to substantiate the participation of mantle fluids in the formation of lithotectonic complexes that are quite different beneath the continent and the marginal Sea of Japan.     

Vertical fault systems in the tectonosphere geoelectrical section in petroliferous domains of Sakhalin Island (Russia) and Gulf of Tonkin (Vietnam): Evidence from magnetotelluric sounding

The transverse current anomalies evident from magnetotelluric sounding (MTS) data in the transition zone from the Asian continent to the Pacific Ocean and a geoelectrical model suitable for explaining these effects are discussed. Using simulation results and new MTS data on Sakhalin and northern Vietnam, ultra-deep fluid–fault system (UDFFS) models are constructed, comprising steeply dipping low-resistivity and high-resistivity linear bodies which penetrate through the whole section of the lithosphere, continuing deep into the asthenosphere. The structure of these systems reflects the development of deep and ultra-deep fault zones, along which mantle-originated fluids may migrate through sediments to reach the surface. This allows the anisotropic–conductive fractured structures adjacent to these faults to be considered as being most favorable for hydrocarbon accumulations.