Original music by Bob Blackshear: Nashville recording artist Song writer and singer Sun City Resident

Tramping Geology through the Appalachians

Vagabonds & Sojourners Tramping Geology: The Appalachian Mountains

Session 1: Getting Started

An Overview of the Next 6 Weeks

Remember our field trip, Nov. 3rd

And now, Geology in the News

Geology in the News

Next, diamonds reveal geology of the deep “earth furnace” that generates many of our natural metallic resources

New York Times, Sept.15, 2011

Geology in the News

New York Times, Sept.16, 2011

Continent

Oceanic crust

Mantle plume (hot spot)

And, China turns out our “green” lights, at least for a while

Geology in the News

New York Times, Sept.16, 2011

Now to “playing in the sand pile” in McCulloch County, Texas Austin American statesman, 9-18-11

Geology in the News

McCulloughCounty

Austin

Up close

McCulloughCounty

Sand quarries

500 milli

on year old sandstones

The big picture: why sand here? Is the favorable sand elsewhere?

McCulloch County

Ancient beach sands

Now to an earthquake in Himalayas

North America 505 million years ago

McCulloughCounty

Geology in the News

India

Tibet-China

6.9

Geology in the News

Geology in the News

Nile geosyncline gas prone

Geology in the News

Nile geosyncline gas prone

Cyprus Offshore territory

Back to the Western Hemisphere

Expensive production from deep water (6,000 feet+) Brazil and Canadian tar sands forecast to provide oil to replace diminishing resources in Mexico and Venezuela.

Geology in the News

Computer modeling of oil & gas reservoirs using seismic, drilling, production, and conceptual data

Now, back to the Appalachians

Vagabonds & Sojourners in the Appalachians Six Sessions

Return to NC & follow the Great Valley throughVA, WV, MD, PA, NY, CT, &VT into Canada

Begin inNorth CarolinaBlue Ridge MtsFollow the Blue

Ridge to Georgia& Alabama

As we follow the Great Valley we’ll: 1. explore the heart of the Appalachians 2. note to economic resources of the interior 3. relate human history to the last great continental glacier

Where are the lands of the Sojourners?

4

1

5

4

711

14

The Lands of the Sojourners

The

App

alac

hian

Geo

logi

c Pr

ovin

ce

2

3

1

17

5

14

Back to Session 1

0

Sandi’s first geology field trip: Wisconsin Dells age 6 months

Vagabonds & Sojourners Tramping Geology: The Appalachian Mountains

Session 1: Getting Started

What is a geologic mountain?

What is a geologic mountain?

Rocks deformed by the collision of two plates of the earth’s crust

Mountains grow to great heights & aregradually destroyed by weathering & erosion

Mountain Classification

Youthful Mountains: Washington State

Mature Mountains: Mount Mitchell, North Carolina

Old Age Mountains: Granville Range Llano County, Texas

What is a geologic mountain?

Rocks deformed by the collision of two plates of the earth’s crust

Mountains are composed of folded, faulted, and melted rocks

Mountains grow to great heights & aregradually destroyed by weathering & erosion

Blu

e R

idge

Mou

ntai

ns

Gre

at V

alle

y

Valley & Ridge Piedm

ont

Coa

stal

Pla

in

Folded & faulted rock layersPar

tially

mel

ted

rock

mas

s

Melted rock masses

Folds, faults, and melted rocks

Appalachian Geologic Province

What is a geologic mountain?

Rocks deformed by the collision of two plates of the earth’s crust

Mountains are composed of folded, faulted, and melted rocks

Mountains grow to great heights & aregradually destroyed by weathering & erosion

Mountain building exposes different rock types at the surface

Blu

e R

idge

Mou

ntai

ns

Gre

at V

alle

y

Valley & Ridge Piedm

ont

Coa

stal

Pla

in

Folded & faulted rock layersPar

tially

mel

ted

rock

mas

s

Melted rock masses

Folds, faults, and melted rocks

What type of rocks do we have in theValley & Ridge Province?

A Land of Long Ridges and Valleys

Sedimentary rocks of all kinds

What made the ridges & valleys?

A yellow

sandy rock made prom

inent ridgesA b

lack

mu

d s

ton

e m

ade

this

str

eam

val

ley

Den

se w

hite

lim

ey r

ock

mad

e lo

w r

idge

s

What made the valleys & ridges?

A g

ray soft ro

ck mad

e these lo

w h

illsSandstones, Limestones, & Shales: rocks of the Valley & Ridge Provincerocks made from sediments deposited

in the oceans along continental margins

Sediments RocksSediments Rocks

Sediments accumulate in oceans Sediments accumulate in oceans at continental marginsat continental margins

They accumulate in layers, They accumulate in layers, one on top of anotherone on top of another

They are composed of: They are composed of: sand, mud, &/or sea shellssand, mud, &/or sea shells

How do these sediments become rocksHow do these sediments become rocks??

Creating the Three Sedimentary Rock TypesCreating the Three Sedimentary Rock Types

Limestones: made from sea shellsLimestones: made from sea shells

Sandstones: made from “ beach” sandsSandstones: made from “ beach” sands

Shales: made from mud and siltShales: made from mud and silt

A Simple ExampleA Simple Example37

Cross Section showing different Sediment layers

Sand layer

Mud layerShell layer

How do these soft sediments become solid rocks?

Let’s follow one shell layer as it becomes a limestone

How are Solid Rocks Formed?Example: Limestones in Williamson County

Edwards started out as a “shell” layer 400 feet thick

What happened next?

39

Burial, compaction and dewatering.

Layer after layer of sediment deposited on top of Edwards “shell” layer

40

Continued burial to depths as deep as 10,000 feet and deeper

Edwards shells recrystalize to

limestone with fossils

41

Many more layers of sediment

Many more layers of sediment deposited on top of Edwards

deposited on top of Edwards

What happens to newly formed rocks?

Uplift brings to the surfaceUplift brings to the surface natural resources created atnatural resources created at great depth: e.g. metals, coal, oil, etcgreat depth: e.g. metals, coal, oil, etc

42

Deeply buried Edwards Limestone layer Uplifted, Weathered, and Eroded

What did we find east of the Valley & Ridge Province?

Valley and Ridge province

Great Smoky and Blue Ridge mountains

What type of rocks do we find in these mountains?

What type of rocks do we find in the Blue Ridge Mountains?

Metamorphic Rocks:

sedimentary rocks buried to great depth, squeezed , crushed, & partially melted

Origin of metamorphic rock types:sandstone = quartzitelimestone = marbleshale = slatesandstone + shale = schist = gneiss**

** most common metamorphic rocks rocks of the Blue Ridge Mountains

Parallel to & east of the Blue Ridge is the Piedmont geological province

The Blue Ridge Mountains

Blue Ridge mountains

300 milli

on year old m

etamorphic rocks

Great Smoky Mountains 600 million year old sandstones & shales

Geologic Provinces of North Carolina

Coastal P

lain

1 to 65 m

illion year o

ld sand & clay

Offshore

Contin

ental Shelf

Recent sand &

clay

Piedmont hills

300 m

illion year o

ld

metamorphic & ig

neous rocks

The Piedmont geologic province Igneous & metamorphic rocks

What is an igneous rock?

What is an igneous rock?

Remember that Metamorphic Rocks are:

sedimentary rocks buried to great depth,

squeezed , crushed, & partially melted

Origin of metamorphic rocks:sandstone = quartziteshale = slate limestone = marble

An igneous rock one formed by complete melting & cooling of a pre-existing rock

Two principle igneous rocks: granites-rhyolites & basalts-gabbros

granitebasalt

Where do we find igneous rocks? Let’s look at the big picture

The Solid Earth

Rocky Crust

Plastic RockyUpper Mantle

Focus on the rocky crust

The Earth’s Rocky Crust: Two Types

Oceanic Crust: 5 miles thick under the oceans: basalt

Continental Crust: 20 to 50 miles thickmakes the continents: granite

The Mantle: “Molten” (plastic) rock below the crustsLet’s look at the Oceanic Crust

The Earth’s Oceanic CrustThe Rocky top of the Mantle

Oceanic Crust: basalt 5 miles thickOcean

The Earth’s Mantle plastic (molten) rocks

A world view

Oceanic Crust: dark colored rocks dense rocky top of the mantle

Next the Continental Crust

Oceanic Crust: dark colored rocks dense

rocky top of the mantle: basalt

All the dark blue are basalt

All the dark blue are basalt

The Earth’s Continental Crust“Floating” on the Mantle“Floating” on the Mantle

Oceanic Crust

The Earth’s Mantle

Continental Crust

A world view

Continental Crust: light colored rocks less dense than oceanic crust

“floats” on the mantle: granite

How “thick” is North America compared to the whole earth?

Rad

ius =

4000 miles

Interior of Our Earth

Our Earth

8000

mile

s

4000 miles = radius

How thick isa continent?

2000 miles

How thick isa continent?

1000 miles

How thick isa continent?

500 miles

How thick isa continent?

8000

4000

2000

1000500

100 miles thickHow thick isa continent?

A continent is only 25 to 50 miles thick!

Just one half to one quarter as thick as this orange line

How far does North America extend?

Center of the earth

Equator

West

NorthPole

North America

How far does North America extend?

SouthPole

South Africa

Cut the earth in half through the poles

The earth’s rocky crust is broken into seven major separate plates plus a number of small plates

Conclusion: continents are a thin veneer on the surface of our earth

Yet they move as “plates” over the face of the earth through time

The Earth’s Crustal Plates Today

From E. A. Keller, 1996, Environmental GeologyFrom E. A. Keller, 1996, Environmental Geology

PacificPlate

North American Plate

Crustal plates move during geologic time

Plate motion in geologic time: 1. moves continents into different climate zones and2. creates mountains when the plates collide

Eurasian Plate

African Plate

Evidence of plate motion

Recent earthquake

The Earth’s Earthquakes and Volcanoes Evidence of Plate Motion Today

From E. A. Keller, 1996, Environmental GeologyFrom E. A. Keller, 1996, Environmental Geology

Recent earthquakes

Mineral Virginia

How were the plates configured when the Appalachian Mountains were created by plate collision?

270 million years ago: (Permian Period)

The Appalachian Mountains have just been formed by the collision of North America with South America-Africa

Let’s look at a more detailed map

North America

South America

Africa

South American-African plate

North American plate

European plate

Plate collision Appalachian Mountains

A look at the collision of crustal plates Check “hidden” figs. 23 thru 28Now to the Appalachian Mountains

Original music by Bob Blackshear: Nashville recording artist Song writer and singer Sun City Resident

Tramping Geology through the Appalachians

Geology in the News

India

Tibet-China

6.9

Geology in the News

Geology in the News

Nile geosyncline gas prone

Geology in the News

Nile geosyncline gas prone

Nile geosyncline gas prone

Cyprus Offshore territory

Expensive production from deep water (6,000 feet+) Brazil and Canadian tar sands forecast to provide oil to replace diminishing resources in Mexico and Venezuela.

Geology in the News

Computer modeling of oil & gas reservoirs using seismic, drilling, production, and conceptual data

Now back to the Appalachians

As we define the history and geology of the Appalachian Mountains we’ll also focus on how human history was shaped by the geological events that created these mountains

But first, a little about Geologic Time

Geologic Time Scale

HumanHistory

AppalachianMountains formed

Our focus: last 570 million years

Geologic Time: Last 570 Million Years

Last 5 Million YearsThe time of us “humans”

570

,000

,000

yea

rs

AppalachianMountains

Geologic Time Line: last 5 million years“Humanoid & Humanid” Fossil History

5 million ago

5 million ago

OldestOldestHumanoidsHumanoidsKenya 1970Kenya 1970

Volcanic mudVolcanic mudFootprintsFootprintsTanzania, 1978Tanzania, 1978

NowNow

Homo Sapiens

Homo Sapiens

Written Human histo

ry

Written Human histo

ry

Where are early human fossils found?

Hot Spots under Africa today

Current Known Earliest Humanoid Fossils

From: Ron Redfern, 2000, Origins

General Area of Oldest Human ancestors

A closer viewA closer look at the last 5 million years

1 million years ago

2 million years ago

3 million years ago

4 million years ago

Today

Columbia University Lamont Geol Inst 2011

A closer look: the last 1 million years Homo erectus & Homo sapiens

Added NY Times 9-11

You & Me

Homoerectus

HomoAntecessor/mauritanicus

Homorhodesiensis

Homoneanderthalensis

Homo sapiens

Homoergaster

Focus on Homo sapiens

Times of Continental Glaciation:Northern Hemisphere

http://en.wikipedia.org/wiki/File:Humanevolutionchart.png

Awesome Humans: 1. reasoning 2. conscience 3. adapt to any environment 4. migrated worldwide in 80,000 years

Expressed in language The Current Homo Fossil Record: Last 300,000 years

Time of WrittenWorld History

Last ice age

Human history time line

One MillionOne MillionYears AgoYears Ago NowNow

Human History Time Line: aka Recent Geologic Time Line

NowNow100,000

100,000

Years Ago

Years Ago

Last Ice Age

ADAD human human

history history BCBC

100,000

100,000YearsYears

1,000,000

1,000,000

YearsYears

500,000

500,000

YearsYears

12,000

12,000Years

Ago

Years Ago

Next, Eurasia 10,000 years ago

Last continental glacier:Eurasia

Last continental glacier:North America

Human landpath

Other views of human migration

Rift Valleys

Nile River

Migration of Humans into Eurasia

Possible Migration Route of Humans into the Western Hemisphere

It’s a 15,000 mile walk from Kenya

to the Southern Appalachians!!!

More specific routes

Alternate route current theory: Asia to North America by sea

Alternate route current theory: Asia to North America by sea

The awesome challenge of migrating by sea

The awesome challenge of migrating by sea

Early human artifacts in the vicinity of the Appalachian Mountains

Appalachian Mountains

Pre-Clovis artifact sites

Evidence of early humans in the Appalachians

But when did they first come to North America?

Might it have been while the glacier was growing rather than when it was at it maximum extent?

Last Four Ice AgesHomo sapiens

Looking at the last glacial period

15,000 years ago pre-Clovis

35,000 years ago glacial recession

Possible migration of early humansinto North America 35, 000 years ago

The big picture

Last glacial period

Possible Intra-glaciation Migration of Humans from Asia to North America

35,000 years ago mid-late glacial period

15,000 years ago

What did early humans find on their way to Appalachia?

Possible drainage challenges of migration during a glacial recession

What might the Canadian portion of the migration route looked like?

North South

Glacier

Cold hostile climate!

Possible drainage challenges of migration during a glacial recession

Cold hostile clim

ate

What did First Nation People find when they finally got to Appalachia?

Appalachian Mountains

Melting glacier

Maximum extent of last glacier

What did Appalachia look like asFirst Nation People approached it from the west?

Following the rivers, stayingaway from the melting glacier

A Land of Long Ridges and Valleys

And east of this region

What made the ridges & valleys?

Blue Ridge Mountains

Valley & Ridge province

Ridge RidgeVa

lley

Valley

Valley

Next Week

First Nation People arrive andexplore Southern Appalachia

Next Week