Question

Question 11 2 pts Which of the following metamorphic rocks is incorrectly paired with its parent rock? O eclogite--basalt schist--shale serpentinite--basalt marble--sandstone Question 12 2 pts Which of the following lists of foliated rock types is arranged according to increasing metamorphic grade? slate, amphibolite, schist, phyllite slate, phyllite, gneiss, schist slate, phyllite, schist, gneiss schist, phyllite, amphibolite, gneiss schist, phyllite, gneiss, slate

Answer 1

11. The incorrectly paired rock and its parent rock is marble and sandstone. A sandstone is aranaceous clastic sedimentary rock, which when undergoes contact metamorphism , results in formation of ganulose textured rock, quartzite ( SiO2 abundant ) . Marble is a thermally metamorphosed rock with its parent rock being limestone.

Eclogite is a high grade metamorphic rock which contains green omphacite ( soda rich pyroxene ) and red pyrope( garnet) . These are found at the subduction zones , near the upper mantle due to high grade metamorphism of basalt.

When an argillaceous rock such as shale undergoes dynanim metamorphism, it gets metamorphosed into slate . With further increase in metamorphism , is converts into phyllite . At higher grade, the phyllite gets converted in a rock with schistosity called as schist.

Serpentinite consists up of serpentine group of minerals ( antigorite, lizardite and chrysotile). It if formed at low temperature metamorphism in the presence of chemically active fluids. The protolith is mafic or uktramafic that has pyronxene and olivine. These minerals undergo hydrolysis and produce sepentine group of minerals .