+ All Categories
Home > Documents > Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology...

Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology...

Date post: 18-Dec-2015
Category:
Upload: simon-pitts
View: 225 times
Download: 5 times
Share this document with a friend
Popular Tags:
60
Introducing Geology Introducing Geology
Transcript
Page 1: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Introducing GeologyIntroducing Geology

Page 2: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

What is Geology?What is Geology?

• Geology - the scientific study of Earth.– Physical Geology is the study of:

• Earth Materials– Minerals

– Rocks

Page 3: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

GeologyGeology• Processes that Occur on Earth’s Surface

– Weathering, the natural decomposition of minerals and rocks. The final product of weathering is soil.

Brice Canyon, UT

Page 4: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Surface ProcessesSurface Processes• Erosion - Movement of Weathered Earth

materials on Earth’s surface

Page 5: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Surface Processes (cont.)Surface Processes (cont.)• Uplift

– Volcanic and/or tectonic forces build crust up above sea level

Page 6: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

UpliftUplift

– Removal of material by erosion allows isostatic uplift of underlying continental rocks.

Page 7: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

IsostasyIsostasy

Figure 1-16A

• Archimedes’ Principle– Every floating object is pushed upward by a buoyant

force that is• Equal to the weight of the displaced fluid

Page 8: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Isostasy (Greek for “equal standing”)Isostasy (Greek for “equal standing”)

• Earth’s crust consists of buoyant blocks of rock.– They float in gravitational

balance on top of the mantle

• Isostatic equlibirum– Occurs when the

buoyant force equals the opposing gravitational force.

– Equilibrium Line• Separates the iceberg’s

submerged root from its exposed top.

Figure 1-16

Page 9: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Surface Processes (cont.)Surface Processes (cont.)• Deposition

– Loose sediment is deposited in low areas when transport agent (water, ice, wind) loses its carrying power

– Earlier sediments get buried by later ones and harden into sedimentary rock

Page 10: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Structure and Processes of Structure and Processes of Earth’s InteriorEarth’s Interior

Gravity Meter

Magnetometer

Seismographs

Page 11: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

TectonicsTectonics

• The study of the origin and arrangement of Earth’s structural features which include– Folds and faults but also – Continents– Mountains– Earthquake regions.

Page 12: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Plate TectonicsPlate Tectonics

• Earth’s lithosphere (the crust and the rigid upper mantle) is divided into several large, thick plates that – slowly move and change in size and shape.

• Plate boundaries are the sites of intense geologic activity (e.g., earthquakes and volcanoes).

Page 13: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Tectonic PlatesTectonic Plates

Page 14: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Practical Aspects of Practical Aspects of GeologyGeology

Page 15: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Practical Aspects of GeologyPractical Aspects of Geology

• Natural Resources– All manufactured objects

depend on Earth’s resources

– Localized concentrations of useful geological resources are mined or extracted

– If it can’t be grown, it must be mined

– Most resources are limited in quantity and non-renewable

Page 16: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Resource Extraction and Resource Extraction and Environmental ProtectionEnvironmental Protection

• Coal Mining– Careless mining can release

acids into groundwater

Page 17: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Resource Extraction and Environmental ProtectionResource Extraction and Environmental Protection

• Petroleum Resources– Removal,

transportation, and waste removal can damage the environment.

Page 18: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Alaskan PipelineAlaskan Pipeline

• Completed in 1977– 1,250 km long– Final cost of $7.7 billion (estimated at $900 million)

• Alaska provides as much as 20% of U.S. domestic oil• Built on permafrost – engineering problems• Earthquake prone region

– Sections jointed to allow shifting of as much as 6 meters without rupturing

National Petroleum Reserve - Alaska

Arctic NationalWildlife Refuge

Page 19: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Exxon Valdez Oil Spill - 1989Exxon Valdez Oil Spill - 1989

• 240,000 barrel of crude oil spilled into Prince William Sound

• Devastating effects on wildlife and the fishing industry

Page 20: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

A “fix” to the energy crisis?A “fix” to the energy crisis?

• North Slope ‘s Arctic National Wildlife Refuge– Extreme points of view which are more emotional than scientific

• Any significant and potential oil field should be developed without regard to environmental impact

• Any intrusion on an ecological environment is unacceptable

Page 21: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Geologic HazardsGeologic Hazards

Page 22: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

EarthquakesEarthquakes• Shaking can damage buildings and break utility

lines.

Page 23: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Undersea Earthquakes can Generate Undersea Earthquakes can Generate TsunamisTsunamis

Sumatra earthquake and tsunami – December 26, 2004

Page 24: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Sumatra TsunamiSumatra Tsunami

Marina beach in Madras, India

Commercial area of Banda Aceh, Northeast Indonesia

Page 25: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

VolcanoesVolcanoes

Mt. St. Helens, USA1980

Hawaii, USA

Mt. Pinatubo, Philippines1991

Page 26: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Mass MovementMass Movement

Mudflows in Armero, Colombia was buried under 8 meters of mud1985

Page 27: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Mass MovementMass Movement

Page 28: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

FloodsFloods

Page 29: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Wave ErosionWave Erosion

Page 30: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Earth’s Heat EnginesEarth’s Heat Engines

• Heat Engines convert heat energy into mechanical energy.

Heat energy is converted tomechanical energy

Page 31: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Earth’s External Heat EngineEarth’s External Heat Engine

• Primary driver of circulation in the– atmosphere (weather)– Hydrosphere (ocean

currents

• Controls weathering of rocks at Earth’s surface

Page 32: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Earth’s Internal Heat EngineEarth’s Internal Heat Engine

• Hot, buoyant material deep within Earth moves slowly upward

• Denser material move downward• Primary driver of

– Volcanism– Tectonics

Page 33: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Earth SystemsEarth Systems

• Earth has four major systems.

• Each system is shaped by a related set of processes and parts.

• They are closely connected and interact with one another.

• This means that a change in one system can cause a change in another.

Page 34: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

An Interdisciplinary Approach to An Interdisciplinary Approach to Studying EarthStudying Earth

• The way in which individual components of land, water, air, and life forms are connected must be understood.

• A system is– Any size group of interacting parts that form a

complex whole to serve a function– Most natural systems are driven by sources of

energy that move mater and/or energy from one place to another.

Page 35: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Earth’s Four SpheresEarth’s Four Spheres

• Earth is divided into four independent parts• Each loosely occupies a shell around Earth - This why they’re called spheres

Page 36: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

The GeosphereThe Geosphere

• The solid Earth• The largest sphere

– Extends from the surface to the center of the planet

• Three principle regions based on compositional differences– Crust– Mantle– Core

Page 37: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

The AtmosphereThe Atmosphere• A very shallow layer of

gases• 99% is within 30 km (20

mi) of Earth’s surface• An integral part of our

planet– Provides the air we breath– Protects us from harmful

short-wave solar radiation• Energy exchanges

between Earth’s surface and the atmosphere and space produce weather.

Page 38: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

The HydrosphereThe Hydrosphere

• The collective mass of water found on, under, and above Earth’s surface

• The hydrosphere includes . . .

Page 39: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

OceansOceans

• Cover nearly 71% of Earth’s surface• Average depth is 3,800 meters (12,500 ft.)• Accounts for 97% of Earth’s water

Page 40: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

StreamsStreams

Page 41: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

LakesLakes

Page 42: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

GlaciersGlaciers

Page 43: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Ground WaterGround Water

Page 44: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

CloudsClouds

Page 45: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Volume ComparisonsVolume ComparisonsVolume of the

Entire HydrosphereVolume of the

Entire Atmosphere

Page 46: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

The BiosphereThe Biosphere• Includes all life on Earth• Most is concentrated near

Earth’s surface

Page 47: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Distribution of Earth’s WaterDistribution of Earth’s Water

Page 48: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Geologic TimeGeologic Time

““Nothing hurries geologyNothing hurries geology””

- Mark Twain- Mark Twain

Page 49: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

What is Time?What is Time?

• It is our sense of one thing happening after another.

• We need standards of time for the convenience of everyday life.

• Time is how we sense and record changes in the environment.

Page 50: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Units of timeUnits of time

• As humans we think of time related to personal experience.– Seconds– Minutes– Hours– Month– Years– Decades– Centuries– Millenia

However, you will see that when we talk about Earth history, even using a

millennium isn’t sufficient because of Earth’s vast age.

Page 51: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Deep TimeDeep Time

• When we study history 200, 1,000 or even 2,000 years seems like a long time.

• Geology involves vastly greater amounts of time– This is referred to as deep time.

Page 52: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Geologic ProcessesGeologic Processes

• Most are slow but relentless– Reflecting the pace at which the heat engines work– It’s unlikely that a mountain will visibly change shape

or height during a human lifetime

Page 53: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Geologic ProcessesGeologic Processes

• In a geologic time frame– Most mountains are probably eroding “rapidly”

Uluru is a great block of uptilted sandstone in the heart of Australia's Outback. This region may be the world's best-developed peneplain,

and Uluru its best-known monadnock.

Page 54: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

To a geologist . . .To a geologist . . .

• “Rapidly” may mean within a few million years.

• A “fast” process– Started and completed within a few million

years.– For example . . .

Page 55: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Rate of Plate MotionRate of Plate Motion

• At a mid ocean ridge– 1 cm/yr movement– 100,000 years for the

seafloor to move 1,000 km (100,000 cm in one km)

Page 56: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Some geologic processes do occur quickly Some geologic processes do occur quickly Mt. St. Helens

Page 57: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Landslides Occur QuicklyLandslides Occur Quickly• Tully Valley landslide on April 27, 1993• Occurred after heavy precipitation of 190 mm (7.5 in) during April in conjunction with melting of a winter snowpack

Page 58: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

Scale Model of Earth HistoryScale Model of Earth History

Page 59: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

The Geologic Time ScaleThe Geologic Time Scale

• Earth history is subdivided into time units based on:– The fossil record– Extinctions

Page 60: Introducing Geology. What is Geology? Geology - the scientific study of Earth. –Physical Geology is the study of: Earth Materials –Minerals –Rocks.

The Geologic Time ScaleThe Geologic Time ScaleThe “calendar” into which geologic events are placed.The “calendar” into which geologic events are placed.

Figure 1-03


Recommended