SOLVED

21) According to the chart in the text, which rock has the finest grain size? A) slate B) gneiss C) marble D) phyllite 22) Which of the following lists the rocks in the order of increasing grain size and increasing grade of metamorphism? A) phyllite, slate, schist B) schist, slate, phyllite C) slate, phyllite, schist D) slate, schist, phyllite 23) ________ is typically formed by metamorphism of a sandstone. A) Marble B) Slate C) Amphibolite D) Quartzite 24) Which of the following rocks changes from shale in low-grade metamorphic environments? A) fault breccia B) migmatite C) slate D) foliated hornfels 25) What is the major source of heat for contact metamorphism? A) deep burial and heat from the Earth’s interior B) heat from grinding and shearing on faults C) heat from the spontaneous decomposition of micas and feldspars D) heat from a nearby magma body 26) In which setting would regional metamorphism be most likely? A) at shallow depths below an oceanic ridge or rift zone B) at shallow depths along major transform faults in the continental crust C) at great depths in the crust where two continents are colliding D) at shallow depths beneath the seafloor where water pressures are immense 27) Graphite is identified in a particular schist. Which one of the following conclusions is justified? A) The rock also contains diamonds; both are crystalline forms of the element carbon. B) The schist formed from a quartz-rich, sedimentary limestone. C) The graphite lubricated shearing movements along a fault, causing a schist to form. D) The pre-metamorphic rock was a shale or mudstone containing organic matter. 28) Amphibolite is a foliated metamorphic rock composed principally of hornblende and plagioclase. How does it form? A) by contact metamorphism of sandstone along the contact with a granitic batholith B) by regional metamorphism of volcanic rocks such as basalt C) by gouging and crushing of limestone along a fault D) by the impact of an asteroid on interbedded sandstone and shale 29) What term describes the zone of contact metamorphism surrounding an intrusive magma body? A) aura B) auricle C) oracle D) aureole 30) During metamorphism, what is the major effect of chemically active fluids? A) They increase the pressures in deeply buried, regional-metamorphic zones. B) They aid in the movement of dissolved silicate constituents and facilitate growth of the mineral grains. C) They prevent partial melting so solid rocks can undergo very high temperature regional metamorphism. D) They facilitate the formation of schistosity and gneissic banding in hornfels and slates. 31) What three, metamorphic rocks come from the parent rocks of shale, mudstone, or siltstone? A) slate, phyllite, and silt B) slate, silt, and quartzite C) silt, marble, and phyllite D) migmatite, marble and quartzite