Metamorphism Of Shale And Granite

During this transformation clay particles in shale transform into micas and increase in size.

Metamorphism of shale and granite. Hence these shale samples have experienced low grade metamorphism due to granite intrusion. The higher the temperature of metamorphism the higher the metamorphic grade. When a rock is contact altered by an igneous intrusion it very frequently becomes more indurated and more coarsely crystalline. The quartz in granite begins to melt at 650 c so if we find a migmatite where quartz has melted in a granitic rock and we know the temperature in the region increased with depth by about 25 c per kilometer we could estimate the depth that the.

Starting with a shale describe the textural changes that would occur to the rock during prograde metamorphism with differential stress conditions present. Beginning with a shale parent barrovian metamorphism produces a sequence of metamorphic rocks that goes through slate and then through phyllite schist and gneiss. Contact metamorphism will lead to significant changes in mineralogy organic geochemistry and microstructure e g microcracks pore size and shape of shales. In order to investigate the influence of granite intrusion on shale gas preservation we selected the luocun section in south china where the early cambrian shales i e the hetang.

Regional metamorphism can transform shale into slate then phyllite then schist and finally into gneiss. Because the luocun section is located in the sedimentation center of the hetang. Describe the following non foliated metamorphic rocks a amphibolite b quartzite c marble d hornfels. Shale granite schist and phyllite why will metamorphic rocks found in a contact metamorphism aureole be nonfoliated.

Shale slate phyllite schist gneiss partial melting match each rock with its first order metamorphic equivalent the first rock it would turn into when metamorphosed. A shale may become a dark argillaceous hornfels full of tiny. Why is retrograde metamorphism uncommon. Many altered rocks of this type were formerly called hornstones and the term hornfels is often used by geologists to signify those fine grained compact non foliated products of contact metamorphism.

The best known and most commonly seen metamorphic rocks are those produced by barrovian also called regional metamorphism. Because the main agent of metamorphism is heat which will result in intergrown crystals. What sequence of rock types will shale pass through with successively higher grades of metamorphism. In contrast the calculated t peak of samples aj 14 aj 18 and aj 21 are 276 284 c which fall in the temperature range 200 300 c estimated from ki index of shales.

Gneiss can form in several different ways.