What is Geology
Physical
examines the materials composing Earth and seeks to understand the many processes that operate beneath and on its surface
Upper Mantle
extends from the base of the crust to a depth of 660 km (410 miles) • transition zone lies below the asthenosphere, it is much denser
Lower Mantle
from a depth of 660-2900 km (410 - 1800 miles) is the lower mantle • weight from the overlying rock causes the mantle to strengthen with depth • high pressure and temperature allows rock to flow slowly
Atmosphere
gaseous envelop that surrounds Earth and makes it hospitable by providing us with oxygen to breath and protecting us from the suns heat and radiation.
Biosphere
includes all life on earth. Some life forms live deep within the soil, or even deep in the ocean, but compared to the size of the planet life still is confined to the surface.
Crust
relatively thin, rocky outer skin of Earth Composed of continental crust and oceanic crust
Asthenosphere
weaker and the rock is slightly melted
Oceanic Crust
7km thick and composed of basalt
Earth's Mantle
82% of Earth's volume, solid, rocky shell that extends to a depth of 2900km, dominant rock type is called peridotite, a very dense rock, divided into the upper mantle and lower mantle
Pacific Northwest Bioregion
All watersheds drain to the pacific through the temperate rainforest
Sedimentary Rock
Consists of particles derived from the weathering of other rocks.
Lithosphere
Crust and the upper mantle, cool and rigid can mechanically detach from the asthenosphere allowing motion
Relative Dating
Dates are placed in their proper sequence or order without knowing their age in years
Logos
Discourse
Accretion
Dust and elements begin to coalesce into planetary bodies, Earth formed 4.7 billion years ago
Geo
Earth
Resources
Energy, water, soil, ore minerals
Igneous Rock
Form when molten rock solidifies at the surface (extrusive) or beneath the surface (intrusive).
Chemical Differentiation
High density metals like iron and nickel sunk to the core while lighter material like oxygen, silica, aluminum rose to the surface
Earth's Core
Iron-nickel alloy • Extreme pressure from overlying weight of the Earth
Metamorphic Rock
Its formation is associated with environments deep below Earth's surface where temperatures and pressures are high and with the forces associated with ancient mountain building processes that occurred in Precambrian time
Uniformitarianism
James Hutton, states physical, chemical, and biological laws that operate today also operated in the past, present is the key to the past
What is the Pacific Northwest?
Land defined by the political boundaries of OR, WA, ID
Solar System
Milky way, formed 5 billion years ago
Geologic Time
Now able to assign fairly accurate dates to events in Earth history
States Involved in Pacific Northwest
OR, WA, ID, N. CA, W. B.C., S. AL
Dominant Rock Type
Peridotite
Geology
Science that pursues understanding of Earth
Historical Geology
Seeks an understanding of the origin of Earth and its development through time
Inner Core
Solid inner core under immense pressure from overlying rock • Inner core is 1216 km (754 miles) thick
Geosphere
The geosphere extends to a depth of 6371 km (4000 miles)
James Hutton
The results, therefore, of our present inquiry is, that we find no vestige of a beginning - no prospect of an end
Radioactive Dating
Today our knowledge of radioactivity allows us to determine numerical ages from rocks
Natural Hazards
Tsunamis, landslides, volcanic eruptions, earthquakes, floods
Hydrosphere
Water on Earth's surface, 71% of Earth's surface is ocean which is 97% of Earth's water, rest freshwater
The Big Bang
13 billion years ago, sent all matter of the universe flying outward
Outer Core
2270km thick, liquid, movement of iron generates magnetic field
Continental Crust
32km thick and composed of many rock types
