Midterm #1 Flashcards
(45 cards)
What is the density range of the Earth’s crust?
2.7 – 3.0 g/cm³
How thick is the Earth’s mantle?
2,900 km
What is the density of the Earth’s core?
10.8 g/cm³
What is the thickness range of the lithosphere?
10 km – 300 km
What characterizes the asthenosphere?
Rock partially melts due to pressure & temperature
What state is the outer core of the Earth in?
Liquid
What is the inner core of the Earth?
Solid
What geological feature is associated with divergent plate margins?
Rift Valleys (e.g., East African Rift Valley)
Give an example of a convergent plate margin.
Oceanic-Continental Subduction, Cascade Range
What do transform faults involve?
Large vertical fractures, side-to-side movement
Define isostasy.
Gravitational balance of Earth’s crust
What is Steno’s Law of Superposition?
Oldest rocks at the bottom
What does the Original Horizontality principle state?
Sedimentary layers initially deposited flat
What texture does obsidian have?
Glassy Texture
What type of texture is associated with explosive volcanic eruptions?
Pyroclastic Texture
What is the characteristic of aphanitic texture?
Fine-grained
What type of rock has a phaneritic texture?
Granite (Coarse-grained, slow cooling)
What are clastic sedimentary rocks formed from?
Rock/mineral fragments (e.g., Sandstone, Shale)
What is regional metamorphism?
Temperature increases 15-30°C per km
What causes contact metamorphism?
Due to igneous intrusions
Give an example of a foliated rock.
Schist, Slate
What is a non-foliated rock example?
Marble, Quartzite
What does strike & dip indicate?
Orientation of rock layers
What is brittle deformation?
Fractures & faults
