Изложены теоретические основы, объясняющие закономерности возникновения и формирования разломных структур в земной коре с позиций ротационной гипотезы структурообразования. Описаны методика выявления и изучения разломов геолого-геофизическими методами и методика использования закономерностей расположения систем разломов для прогнозирования месторождений полезных ископаемых

A crustal-scale ductile shear zone network in the Precambrian granulite-facies crust of Madagascar is examined to determine the nature of the connections between the mantle arid lower crust. Based on three independent data sets - field and satellite mapping, C- and O-isotope geochemistry and gravimetry - this crust is divided into three zones: (1) outside of shear zones; (2) minor shear zones that are <140 km long and 7 km wide; and (3) major shear zones mat are >350 km long (up to 1000 km) and 20-35 km wide. The mantle is uplifted by about 10 km beneath the major shear zones. The major shear zones are rooted in and are inferred to be controlled by the mantle; they directly tapped mantle-derived C02. The small-scale minor shear zones were controlled by crustal processes and focused crustally derived H20-rich±C02 fluids. The regular distribution of the shear zones on a crustal scale is in agreement with models of buckling of the continental lithosphere in a compressional context. The propagation of these mechanical instabilities promoted and channelled fluid flow. These major Pan-African shear zones thinned the crust and were reactivated during the subsequent drifting of Madagascar and opening of the Indian Ocean during Jurassic to Cretaceous times. They also controlled many of the brittle fault zones in the overlying sedimentary basins. Mantle-rooted large-scale shear zones are inferred to be a general feature of cratonic areas reactivated by shear zone systems.

We present a ring-shear apparatus designed to deform soft, ductile rock analogues to arbitrarily high shear strains in simple shear, in experiments attempting to model processes that occur in natural ductile shear zones. The sintered specimen is deformed between two unsupported cylinders by two rotating grips, under a normal and shear stress up to 5 MPa and at temperatures up to 600 K. First results of experiments with octachloropropane (OCP, C3C18) and camphor (C10Hl6O) are presented.