Study Guides (380,000)
CA (150,000)
Western (10,000)
EARTHSCI (200)
all (3)
Midterm

Earth Sciences 1081A/B Study Guide - Midterm Guide: Continental Crust, Oceanic Crust, Rhombohedron


Department
Earth Sciences
Course Code
EARTHSCI 1081A/B
Professor
all
Study Guide
Midterm

This preview shows pages 1-3. to view the full 12 pages of the document.
Solid Rigid
Retains shape
Liqui
d
Flows easily
Conforms to shape
Constant Volume
Gas Flows easily
Conforms to shape
Changes volume to fill
space
Elemen
ts
Atoms with different characteristics
Protons Positive charge
Electro
ns
Negative charge
Neutro
ns
Neutral
Atomic
#
Number of protons
At.
Mass
Protons + Neutrons
Covale
nt
Strongest bonds – share electrons
Ionic Strong – oppositely charged e
Metallic Weak – valence can migrate
Intr/mo
lec
Weak – chemical imbalance - graphite

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Rate of cooling (slow cooling allows crystals to grow larger) affect the crystal
size and shape
Gabbro (P) vs. basalt (A): same composition, different texture
Plate Tectonics Theory that the earth’s crust is a series of plates which move about
the surface
Plates move relative to each other at a slow, but constant rate
Hot material rises up the ridges to form the crust
Cooler, denser slabs of oceanic crust descend into the mantle
Convection Transfer of heat in the mantle
Minerals Naturally occurring, inorganic solid
Definite chemical composition, structure, physical characteristics
Structure determines by positive ions (cations) or negative ions
(anions)
Rock A solid aggregate or mass of minerals
Unit cells Combine to form minerals
Cleavage How a rock breaks – cubic, rhombohedra, or basal
Igneous Crystallized from molten material
Extrusive when created at surface, intrusive when not
Classified by composition and texture
Sediment
ary
Formed by deposition or precipitation of weathers transported
material - sediment
Metamor
phic
Formed by change of existing rock (meta + morph = to change –
form)
Phaneriti
c
Coarse grained (granite) – abundant, associated with mountain
building
Aphantic Fine grained (rhyolite)
Limeston
e
Most abundant – made of calcite
Nonfollat
ed
Texture
Rocks w/ granular texture interlocking grains of granite
Marble = metamorphic limestone/ quartzite = metamorphic
sandstone
Foliated Schistosity – platy minerals show a layers structure, referred to as
schist, ie Gneissic
Gneissic Banded appearance – pressure and heat - follated

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Divergent Plate
Boundaries
Boundaries are located along ocean ridges
Basaltic volcanism
Oceanic continental
plate convergence
Oceanic crust converges with continental crust
Continental-
continental plate
convergence
Self explanatory
Transform fault
boundaries
Numerical or absolute
dating
Radiometric Dating: Using radioactivity to date minerals, rocks, and
geologic events
Principle of radiometric: ratio of parent-daughter; constant decay
Significance of the Tectonic Cycle to the Environment
Global zones o resources (oil, gas, mineral ores)
Global belts of earthquakes and volcanic activities
Impacts on the landscape and global climates
Geologic knowledge or plate tectonics foundation for urban development and
hazard mitigation
Natural processes are repetitive, and therefore predictable
Natural hazards can be linked – hurricanes, flooding, coastal erosion, precipitations,
earthquakes, tsunamis
You can FORECAST and PREDICT hazards
To minimize damage, main factors are; location, probability, magnitude, precursor events,
forecast, warning
Direct Causes Indirect Causes
Loss of life
Dislocation
Property damage
Services and
communication
Emotional distress
Donation of money or
goods
Paying taxes to finance
recovery
Economic recovery
Risk Function of probability of the event
occurring, and the consequences (loss of
life, damage, etc)
Acceptabl
e Risk
Complicated function of society,
consequences and situation
Risk
Assessme
nt
Often problematic because of lack of
information
Today’s Objectives
How natural processes/hazards are beneficial to
people
Link to history, processes, predictions, and risk
assessment
Link between natural hazards, increased
population, and changing land use
Impact related to magnitude and frequency
Benefits of Hazards
Add sediment
Flood pollutant to coast
Creates natural dams
Landslides
Create new land
Measurement of impact
# of deaths – floods,
tornados, lightening
Cost – earthquakes
Catastrophe
Risk to life
Loss of energy
Lack of warning
Population distribution
Are we sabotaging ourselves?
Increased population
•More people affected
•Greater demand to live in hazardous areas
•Urbanization
Increased resource use:
•Forestry = erosion
•Ground water = subsidence
•Wetland removal = increase pollution and erosion
Artificial controls of natural processes – (will
they protect us?)
Perception of hazards – (too much optimism?)
Increasing rock and consequences caused by
oIncreasing population
oChanging population density and distribution
land use
oGlobal climate change
You're Reading a Preview

Unlock to view full version