Download review list 2013

Facts/Concepts to know for Unit 2: Dynamic Crust
 Convection currents in the asthenosphere move the lithospheric plates.
 Plate movement causes earthquakes (and makes mountains, volcanoes and new ocean crust), therefore these
things occur mostly along active plate boundaries.
 There are three types of plate boundaries: convergent, divergent, transform.
 Convergent: Subduction happens if it is ocean and continental or ocean and ocean colliding, crust will be
destroyed (melted); mountains, volcanoes and trenches are made.
 Divergent: new ocean crust and mid-ocean ridges are formed (a rift is a new divergent boundary)
 Transform: features are offset
 Current Plate Tectonic Theory includes Alfred Wegener’s original idea of Continental Drift and the modern idea
of seafloor spreading.
 Continental Drift evidence: Correlation of fossils, rock structures and types, continent shapes, and
climate (glacial) evidence across continents.
 Seafloor spreading evidence: Magnetic anomalies and age of ocean crust (increasing as you move away
from mid-ocean ridge and generally younger than continents).
 Hot spots do not usually occur at a plate boundary. The magma source doesn’t move but the plate over it does,
creating an island chain. (Know how to find direction of movement)
 Waves released by earthquakes are called seismic waves, measured by a seismograph and recorded on a
seismogram. The two main types are P and S.
 P-waves: Primary, push-pull motion, travel through solid and liquid, faster than S
 S-waves: Secondary, shear/side to side motion, only travel through solid, slower than P
 Three seismic stations are needed to find an epicenter. Know how to find:
 P or S travel time (using epicenter distance and ESRT p.11)
 Epicenter distance (using S minus P arrival times and ESRT p.11)
 Origin time (Arrival time minus travel time)
 The area between two plates colliding is where regional metamorphism occurs, with heat and pressure. Contact
metamorphism occurs where the heat of lava or magma touches and changes existing rock. All foliated rocks
are made by regional metamorphism because the pressure causes minerals to align.
 Metamorphic rocks can form from any other rocks that have been changed by heat and/or pressure.
 Metamorphic rocks are usually found in mountainous regions and NEVER come from completed melted rocks
(magma).
 ONLY igneous rocks come from melted rocks (magma or lava).
 Magma cools slowly, underground(intrusively) and forms large crystals. Lava cools quickly, above or near the
surface (extrusively) and forms little or no crystals.
 Igneous texture is crystal size, NOT the feel of the rock.
 Glassy means no crystals, vesicular means holes.
 Igneous rocks have intergrown crystals. Metamorphic rocks have distorted structures.
 Rocks are classified based on their origin (how they form).
 Rocks are made of minerals, minerals are made of elements.
 A substance is a mineral if it:
 Is inorganic
 Is naturally occurring
 Is solid
 Has atoms arranged in a pattern
 Has a definite composition
 Minerals are identified based on physical and chemical properties like hardness, cleavage, luster, streak and
color.
 Physical properties like hardness and cleavage are a result of the internal arrangement of atoms in a mineral.
 Minerals form by evaporation, lava or magma cooling or re-cyrstallization due to heat and pressure.
 Know how to use ESRT pages 1, 5, 6, 7, 11, 16.
 DIAMONDS ARE NOT MADE FROM COAL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!