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