Plate Tectonics & Continental Drift
This scientist proposed that continents were once joined together in a single landmass called Pangaea.
Alfred Wegener
This is the point on Earth’s surface directly above an earthquake’s focus.
the epicenter
A mineral must be naturally occurring, inorganic, solid, have a definite chemical composition, and this.
crystalline structure
What are the three types of rocks?
igneous, metamorphic, sedimentary
This is the correct order of geologic time units from largest to smallest.
eon, era, period, epoch
This layer of Earth is rigid and broken into tectonic plates.
the lithosphere
These smaller earthquakes often occur before the main earthquake.
foreshock
This identification method measures a mineral’s resistance to scratching.
hardness
These igneous rocks cool slowly beneath Earth’s surface.
intrusive igneous rocks
This law states that in undisturbed rock layers, the oldest layer is at the bottom.
The Law of Superposition
This type of plate boundary occurs when two plates move away from each other.
divergent boundary
This deadly volcanic hazard consists of fast-moving hot gas, ash, and rock.
pyroclastic flows
This property describes how light reflects off a mineral’s surface.
Luster
This metamorphic rock texture shows mineral grains lined up in layers.
foliated metamorphic rock
These fossils are used to determine the relative age of rock layers.
Index fossils
This type of continental margin is associated with frequent earthquakes and volcanoes.
active continental margin
How are the focus and epicenter of an earthquake connected?
the focus is the underground origin of the earthquake and the epicenter being directly above it on the surface
This test is more reliable than color when identifying a mineral.
streak
This process turns sediments into sedimentary rock.
compaction and cementation
This dating method provides a numerical age for rocks and fossils.
absolute dating
These four types of evidence supported Wegener’s Continental Drift Hypothesis.
fossil, landform, climate, and rock evidence
What (2) things in lava determine how explosive a volcano eruption will be?
silica content and gas content
What is the difference between cleavage and fracture?
cleavage is clean breakage along a flat plane where fracture is uneven breakage.
This idea explains why rocks are not permanent and can change over time.
The rock cycle
These clues help scientists decide when one geologic time period ends and another begins.
major changes in fossils, climate, or mass extinctions