Geology Exam 1 Flashcards
Why study geology?
-Diverse field: study the geosphere, atmosphere, biosphere, & hydrosphere
-large part of economy
-important to geopolitical relations
-aids in development
-geologic hazards
-geo health
Formation of the earth and moon
-an astroid the size of Mars collided with Earth-4.5 Ga
-molten material was ejected to space, then coalesced as it orbited around earth
How are elements created?
elements lighter than Iron are created by fusion at the cores of stars. heavier elements are formed by supernovae.
composition of core
earths core is solid
composition of mantle and crust
high density rock-mantle
low density rock-crust
planetary differentiation
-different “bulk” chemical compositions in each layer
-the earth is huge and has a dynamic internal structure as well as surface features
earth accretion
-accumulation of matter
-giant outer planets grew by gas accretion
Minerals
-building blocks of life
-a highly diverse group of natural materials
what are the building blocks of rocks
minerals
what IS a mineral? 4 parts
-naturally occurring
-inorganic solid
-orderly crystalline structure
-well defined chemical composition
to geologists, how are rocks used as records?
rocks are physical records (i.e direct evidence) of Earth’s past conditions or processes. e.g volcanic rocks means a volcanic eruption occurred
Silicate minerals
rock-forming
why are silicates so common? what are the main ingredients?
-most minerals within the Earth’s crust
-composed of cations bonded to groupings of silicon and oxygen atoms
how does the Silica Tetrahedron provide structure to silicate minerals?
the Silicon is typically surrounded by oxygen molecules which keeps the crystalline structure stable.
mafic vs. felsic minerals
mafic- dark silicates (ferromagnesium)
felsic- light silicates (non-ferromagnesium)
