PHSC 211 Exam #1 Short Answer questions and answers 100% correct

PHSC 211 Exam #1 Short Answer questions and answers 100% correct Volcanic Activity creates two main types of deposits that can form igneous rocks. What are they? Lava flows and pyroclastic material List the four sizes and measurements of pyroclastic material 1) Volcanic Ash <2mm 2) Lapilli >2mm <64mm 3)Blocks >64mm, ejected solids 4)Bombs >64mm, ejected molten material If ocean crust is rich in ferromagnesian minerals, what type of rocks are on the ocean floor? Basalt What is the mineral composition of continental crust? Abundant quartz and orthoclase, as well as biotite and sodium-rich plagioclase and hornblende When rocks weather into particles, most of the rocks don't stay in place; name three ways weathered rock particles are carried away Water, wind, ice Four sizes of sedimentary grain sizes and measurements 1) Clay < 1/256 mm 2) 1/256 < SILT < 1/16mm 3) 1/16 < SAND < 2mm 4) Gravel >2mm 2 processes sediments are turned into rock with definition Compaction: as sediments are buried, the pressure from overlying layers pushes the clasts closer together, reducing pore space Cementation: If the clasts are fine or very fine, the pressure from compaction can cause the clasts to cling together and form rocks. If the clasts are larger, dissolved minerals will glue them together. How to produce bituminous coal Plant materials are deposited in a swamp-like environment. The materials are preserved and buried. Continuous pressure from overlying layers compact and remove noncarbon material. Further pressure creates bituminous coal Evaporite minerals and how they are deposited Halite and Gypsum (hail could evaporate into water; gypsies use smoke that looks like evaporation) Evaporites form as minerals crystallize as the water in which they have been dissolved in, evaporates Limestone is both chemical and biochemical. Why? Limestone can be formed in the ocean by the compaction and cementation of dead organisms; thus, the limestone would have organic origin. Limestone can also form from the precipitate calcite, which would make limestone chemical What is metamorphism Alteration of the composition or structure of a rock by heat and pressure How are foliation and layering different Foliation involves preferred orientation with elongated minerals; foliation occurs by heat and pressure Layering on the other hand, involves stacking sediments on top of each other. Layering doesn't have to have minerals that are elongated Why is slate good roofing material It is impervious to water and it has slaty cleavage: cleaves perfectly in one plain What is a metamorphic grade The combinations of heat and pressure that produce metamorphism -Low Grade -Intermediate Grade -High Grade What history do metamorphic rocks reveal The journey deep beneath earth's surface where temperatures and pressure create transformation that occur nowhere else on earth