What is the density of the mantle?
Regional Specifics3“>4.5 g/cm34.5 g/cm3, and temperatures in the range of 1000-1500 oC. The uppermost layer of the mantle is more rigid, while the deeper regions are fluid, and it is the motion of fluid materials in the mantle that is responsible for plate tectonics (see section 4.3). What is the average density of the lower mantle?
What is a reverse earthquake?
Regional SpecificsIf the rock mass above an inclined fault moves down, the fault is termed normal, whereas if the rock above the fault moves up, the fault is termed reverse. What is the meaning of reverse in earthquake? How does a reverse fault move? In a reverse fault, the block above the fault moves up relative
Why are oceanic plates denser than Continental?
Regional SpecificsWhy is the oceanic crust more dense? Oceanic crust is denser because it generally melts to a higher fraction than continental crust. When rocks melt to 20–30% like they do at mid-ocean ridges, the result is more dense than when rocks melt to form continental plates, which is typically 1–5%. Why is continental crust less
What are the different eras in the geologic time scale?
Regional SpecificsThe Precambrian, Paleozoic, Mesozoic, and Cenozoic Eras The Geologic Time Scale is the history of the Earth broken down into four spans of time marked by various events, such as the emergence of certain species, their evolution, and their extinction, that help distinguish one era from another. What are the 6 eras on the geologic
What is a sinkhole and how is it formed?
Regional SpecificsSinkholes are formed when the land surface above collapses or sinks into the cavities or when surface material is carried downward into the voids. Drought, along with resulting high groundwater withdrawals, can make conditions favorable for sinkholes to form. How deep is a sinkhole? Sinkholes can be anywhere from a few feet wide and deep,
Is sandstone a crystalline?
Regional SpecificsIs sandstone a crystalline rock? Feldspathic sandstones are derived from granitic-type, primary crystalline, rocks. If the sandstone is dominantly plagioclase, then it is igneous in origin. … This type of rock contains less than 90% quartz grains and more unstable rock fragments than feldspars. Is sandstone clastic or crystalline? Sandstone is a clastic sedimentary rock