an important concern in rock mechanics is non-homogeneity as joints or fault. this noticeable feature of failures in rock is appearance of slip surfaces or shear bands, the characteristics of that are associated with deformation being concentrated in a narrow zones and the surrounding material remaining intact. adopting the joints as fractures, fractures are well known for their effects on the ...

introduction arefi quartz-bearing conglomerate (middle jurassic) is situated within binalud structural zone. the unit is trending nw-se located 25 km south of mashhad. more than 97% of the pebbles are quartz as mono-crystalline, poly-crystalline, and minor fragments of chert, quartzite, and mica schist. less that 3% of the remaining minerals are feldspar, mica, chlorite, hornblende, tourmaline,...

A variety of established and experimental geophysical techniques was used to measure the vertical distribution of fracture permeability in a 229-meter deep borehole penetrating schist and quartz monzonite near Mirror Lake, New Hampshire. The distribution of fractures in the borehole was determined by acoustic borehole televiewer and other geophysical logs. Fracture permeability was estimated by...

Whether or not coarse detrital sedimentary rocks occur within the \3.7 Ga Isua Greenstone Belt (IGB), southern west Greenland, has been debated for some time. Repeated, regional metamorphic, deformational, and metasomatic events have obscured most protolith lithologies leading to misunderstandings about the stratigraphy and environments of deposition. Rocks here interpreted as meta-conglomerate...

[1] The Rand and Sierra de Salinas schists of southern California were underplated beneath the southern Sierra Nevada batholith and adjacent Mojave‐Salinia region along a shallow segment of the subducting Farallon plate in Late Cretaceous time. Various mechanisms, including return flow, isostatically driven uplift, upper plate normal faulting, erosion, or some combination thereof, have been pro...

Wherry discussed the origin of this material and on the basis of mineralogical and structural evidence suggested its derivation from aan original sedimentary type. He concluded that the presence of sillimanite indicated a noteworthy alumina content of the original sediment and thought that very likely the material w’as originally an argillaceous sandstone. The present writer” has discussed the ...

By Korzhinsky and Schrienemakers, methods, phase relations of Mn-Al-Ca-silicates and other minerals in highly oxidized quartzites and schists of blueschist type metamorphism have been discussed. Because, such rocks were extensively studied in central Shikoku of Japan and in Andros and Evvia islands of Greece, they have been considered as thermodynamic system for discussion. The system contains ...