Lecture Exam 2 Flashcards
- Which type of rock is best suited for radiometric dating: limestone, chert, shale, granite, or sandstone?
Granite
*Which fault will see the hanging wall moved down relative to the footwall?
Normal fault
*What type of chemical sedimentary rock is found in petrified wood?
Chert
*Some strike-slip faults are big enough to accommodate movement between two tectonic plates. True or false?
True
*Movements along normal faults can produce alternating upthrown and down-dropped fault blocks. What are the names associated with these blocks, respectively?
Horsts and grabens
*______ is the compass direction of the line produced by the intersection of an inclined rock layer with a horizontal plane.
Strike
*______ is the angle of inclination of the surface of a rock unit measured from a horizontal plane.
Dip
*Which of the following rocks, composed of silt and clay size particles displays fissility: mudstone, shale, siltstone, or claystone?
Shale
*Which answer correctly distinguishes among limestone, dolostone, and chert?
Limestone, which is composed of calcium carbonate, forms by both chemical and biochemical means; dolostone, which is composed of calcium-magnesium carbonate, forms strictly by chemical means; chert, which is composed of microcrystalline quartz, forms most often chemically and to a lesser extent biochemically.
*_____ is the process where calcium ions in limestone are replaced with magnesium or small amounts of iron.
Dolomitization
*A ______ describes the observation of successive changes in a laterally continuous sedimentary layer that are visible and are interpreted as a result of many depositional processes taking place over a large area.
Facies
*The same formation changes laterally from layered evaporates to mud cracked sandstone to conglomerate. Using the facies concept, which of the following is an accurate interpretation?
Shallow Lake, Shoreline, mountain front setting
*Which of the following is a reason that limestone is formed in a relatively offshore position?
The lack of sediment right from land.
*What is the most important factor driving metamorphism?
Heat
*What is the average increase in temperature along the geothermal gradient in the upper crust?
25 degrees C per km
*_____ metamorphism is responsible for the emplacement of metallic ore veins.
Hydrothermal
*Physical rotation of platy minerals will contribute most to the development of foliation in _______ grade metamorphism.
Low
*Can parent rock features such as sedimentary structures and fossils survive low-grade metamorphism?
Yes, they can, because such features can withstand low temperatures and pressures, but will be destroyed in higher metamorphic grades.
*Which of the following materials/facies is most closely associated with shock metamorphism and meteorite impact sites?
Tektites
*What environment produces the blueschist facies?
Subduction zone
*What is a metamorphic facies?
An assemblage of minerals that form in very similar metamorphic environments
- What does “-zoic” in the eras of the geologic time scale referred to?
Life
- In what era is the Jurassic period?
Mesozoic
