Vagabonds Sojourners Tramping Geology The Appalachian Mountains Session

Vagabonds & Sojourners Tramping Geology: The Appalachian Mountains Session 2: First Nation People Arrive & Explore the Southern Appalachian Mountains Where did First People come from? But first, geology in the news

Extraction begun of lithium, magnesium, & copper from very hot brines used to generate electricity in the Salton Sea of southern California Lithium and magnesium are important industrial raw materials in short supply in the USA The Canadian-USA oil pipeline

Bringing oil from the Canadian tar sands to mid-America Unhappy “campers” in the exploration for Marcellus shale gas in New York state

Unhappy “campers” in the exploration for Marcellus shale gas in New York Exploration leases signed 5 years ago are being extended under forced majeure without increased compensation equivalent to compensation being offered today for new leases A new book you may or may not want to read

The Quest: what’s in our energy future and our options Let’s try serious conservation of our energy resources From Patricia Windsor

From Patricia Windsor Government bureaucracy is delaying the creation of a large number of new, high pay jobs by delaying permits to drill in the USA offshore, New York state, etc. What’s not mentioned is the need now to begin the recruiting and training of 1, 000’s of new geologists and engineers to handle the phenomenal growth of the oil and gas industry in the next 40 years Some news from Africa

Geology in the News Diagram up close

Human language began far from central Africa where fossils indicate humans evolved Rift Valley Area Advent of humans? Now recall from last week; where did First Nation Peoples in North America come from?

Human migration out of Africa Last continental glacier: North America Last continental glacier: Eurasia Human land path Several current theories on the migration routes Out of Africa

The awesome challenge of migrating by sea Alternate route current theory: Asia to North America by sea

The awesome challenge of migrating by sea Early human artifacts in the vicinity of the Appalachian Mountains

Evidence of early humans in the Appalachians c a l a n a i h u o M n tai s n p p A Pre-Clovis artifact sites 15, 000 years ago What might have been the environment 15, 000 years ago in Appalachia?

Last Four Ice Ages Homo sapiens Focus on the time of Homo sapiens Looking at the last glacial period: events favoring migration into North America

Possible migration times of early humans into North America: 35, 000 & 15, 000 years ago Last glacial period 35, 000 years ago glacial recession 15, 000 years ago pre-Clovis The big picture

Human History Time Line: aka Recent Geologic Time Line One Million Years Ago Now , 00 15 35 , 00 0 01 Ye 0, 00 ar 0 s. A go 00 0, 0 50 ars Ye 0 00 0, 00 1, ars Ye 00 go 0 A 0, 10 ears Y 10 Ye 0, 0 ar 00 s Now recall the possible Lastroutes Ice Age to Appalachia of t en ns v a Ad um H ? in rica s e an Am m Hu orth N Human history AD

Possible Intra-glaciation Migration of Humans from Asia to North America 15, 000 years ago 35, 000 years ago mid-late glacial period What might have the Canadian portion of the migration routes looked like?

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 ld Co le sti ho te ma cli What did First Nation People find when they finally got to Appalachia?

Melting glacier Maximum extent of last glacier Following the rivers, staying away from the melting glacier p c a l a n a i h s n i ta n u o M What did Appalachia look like as First Nation People approached it from the west? Ap

A Land of Long Ridges and Valleys Time for a little more geology

this y nd sa alle y stre am v low ad e ow ll ye km A t roc y sof A gra rid g es What made the valleys & ridges? ade roc ton em im ey el hit ds mu lac k ns ew Ab s ge id tr en in De m ro ls w hil se lo ep ad m e de th ck ro k ma Marine Limestones, & Shales: How. Sandstones, did these marine rocks get here, The rocks of the Valley & Ridge Province miles from the ocean? rocks made from sediments deposited Let’s go backalong to ourcontinental Central Texas model in the oceans margins of making rocks from sediments

Let’s follow the erosional debris Deeply buried layers are uplifted, weathered and the debris is moved to the oceans 43

River Erosion in Central Texas Land surface 65 million years ago Present day Land surface Con Sedimentary to 65 million years old Weatheredrocks rock 145 debris moved by rive rs to rocks) onth continental (metamorphic in igneous e Gulf of Mcrust exico geosyncline What is a geosyncline? tal C r tine n ust

What is a Geosyncline? Answer: A thick (1000’s of feet) accumulation of rock debris in the ocean at the continental margin Debris brought to the ocean by rivers and spread along the coast by ocean currents

Geosyncline Example: Roc k R land iver d ebr is s of the Iber ia n co ntin Ocean river debris enta l cru A modern example of a geosyncline: The Gulf of Mexico geosyncline st

Example of a Geosyncline: Gulf of Mexico 1. Integration of the debris of several rivers ds Mu p m a w S s d an t n e m w i d w e lo s l S a n h n o s S i r d t e laer Mu d u o M cumwat Ac eep D 2. Accumulation of thick layers of debris S r e at

Subsurface Cross Sections Gulf of Mexico Geosyncline w Ne Sandstone Reservoir Rocks Gulf of Mexico Geosyncline s an le Or 65, 000 feet thick stin Au City Sun Shale Source Rocks Gulf of Mexico Mature Source Rocks 2. Accumulation of thick layers of debris What is the “fate” of all geosynclines?

What is the “fate” of all geosynclines? Sediments in ocean at the margin of the continent Building a new mountain range by crushing & melting the sedimentary rocks creating metamorphic & igneous rocks Where have sedimentary rocks in North America been converted to metamorphic & igneous rocks?

ale s The Appalachian Geosynclinal Model The Fate of Thick Debris in the Sea Rocks at the surface today along Continental Margins s tai n gn eo us ale Mo un ta in s to n Sh an d. I ne mo rph ic to Me ta Fo ld ed Sa n ds Ea s t. D ip an d pi ng Sa n Lim ds est on es an d Sh es The Appalachian geosyncline has been welded back into the North American continent as a mountain range Here’s how mountain building works Debris of the Appalachia geosyncline turned into the Appalachian Mountains

Mountain Building Appalachian Example Mountains welded onto continent Appalachian Geosyncline 250 million years ago Illinois Limestones Ohio Sandstones Pennsylvania Virginia Sandstones and Crushed Melted Shales Rocks = Mountains Purple “mountains” = metamorphic rocks Red “mountains” = igneous rocks Mountain building produces two types of igneous rocks Today’s Gulf of Valencia Geosyncline

Ocean ust r c c i Granite: continental crust Pre-Cambrian granites lt: a s Ba an e c o Mountain building: Partial melting stage

Schists Gneiss Slate

Ocean ust r c c i Granite: continental crust Pre-Cambrian granites lt: a s Ba an e c o Then complete rock melting Mountain building: Complete melting stage

Rhyolite lavas Black basalt lavas Granites at depth Gabbros at depth Then complete rock melting

Schist Rhyolite Basalt Let’s put it all together from the creation of the earth, 4. 8 billion years ago Gneiss Granite Gabbro

Our “earth” 4. 8 billion years ago Hot cloud of gas & dust Hot cloud: Cools forming rocky lithosphere

Hot-gas cloud cools: core, mantle, & crust mantle crust core As the still molten crust forms, it separated into continental crust & oceanic crust

Granite Molten mantle Granite Basalt Continental crust congealing on molten mantle Oceanic Crust congealed Granite

Granite Steam from the cooling ocenic crust Molten mantle forms the oceans Granite Basalt Oceans Oceanic Crust congealed Hot gasses cool to with form sunlight the atmosphere Rain combined begin Granite the weathering and erosion of Granite the continental crust

Erosional debris from the continents is moved by rivers to the continental margins forming geosynclines Granite Molten mantle Granite Basalt When geosynclines have been filled to “capacity” they are crushed & melted into mountain ranges Granite

Mountain Building Granite Molten mantle Granite How are the rock types arranged in all this? Basalt Granite

What rocks are produced by these Geosyncline geologic processes? Sandstone Mountains Continental Crust Granite: coarse grained light color light weight Marble Schist Gneiss Rhyolite Granite Basalt Mantle Gabbro: coarse grained black heavy weight Shale Limestone Oceanic Crust Basalt: no grains black heavy weight Let’s look more closely at rocks

Rocks are made of minerals Minerals are naturally occurring compounds of elements (remember the periodic table from chemistry) Most common minerals: clays (half a dozen): make shale feldspars (half a dozen): make igneous & metamorphic rocks quartz: make sandstones, in granite & rhyolite Now big picture calcite: makethe limestones

Ancient Mountains of North America Appalachian Mountains A schematic diagram of North America

Hypothetical Diagram: Ages of Ancient Mountains of the Continental Crust Back to the Blue Ridge Mountains of Appalachia Crust Original Crust 2 B 3 B Crust: 4. 8 B 3. 5 B 1. 4 B Volume of continental crust appears constant over time. Therefore, original continental crust might have been much thicker that later crust as the various mountains were created by compressing their corresponding geosynclines

The Blue Ridge Mountains of Appalachia ince v o r p e Ridg d n a y Valle ns i a t un o ue l B nd a y k m e g d Ri o Sm t a Gre What type of rocks did they find in mountains?

What type of rocks did they find in mountains? Metamorphic Rocks: sedimentary rocks buried to great depth, squeezed , crushed, & partially melted Metamorphic Rocks of the Blue Ridge Schists What did. Gneisses first Nation People find east of the Blue Ridge Mountains in the Piedmont foothills?

Geological Provinces: Central & Southern Appalachians Pennsylvania Valleys & Ridges of ss, sh, & ls Ohio Mountains of metamorphic rocks Kentucky Tennessee Virginia Foothills of igneous rocks North Carolina What do the igneous foothills look like?

Geological Provinces: Central & Southern Appalachians V e g id s hi ll on t m ed y s n i ta n u o M Pi e all id R & fo f ( e g Mt. Airy granite ot d) e old u o m s n i nta North Carolina R e u Bl Mt. Airy area up close

Blue Ridge Mountains Piedmont foothills Mt. Airy granite area hills Do we find basalts in the southern Appalachian Mountains?

Two Geologic Processes that shape the Earth’s Surface Weathering Erosion Weathering: Natural destruction of the rocky continental crust

Weathering: Natural destruction of the rocky continental crust Causes: sun rain plants wind TIME

WEATHERING: Destroys Rocks Creates: 1. rock debris 2. soils (rock debris + decaying plants) Produces: unique environments

Rock “Debris” 1. quartz sand 2. muds (clays) 3. calcium carbonate solutions Best farming soils: thick clay debris in river flood plains in Temperate Climate Zones Soils & rock debris are carried away by erosion

Erosion: Natural process of moving rock debris to the oceans at the continental margins Products of erosion: topographies rock outcrops river flood plains geosynclines What causes erosion?

Erosion: Causes Moving the weathered rock debris to the sea by: 1. gravity!!! It all goes down hill 2. water: brooks streams rivers Erosion: 1. produces topography 2. exposes different rocks at the earth’s surface 3. creates river flood plains erosional 3. The creates geosynclinestopography of the Southern Appalachians Mountains

Hi lls & va lle ys (to po gr ap hy )A un tai n Mo pp ala ch ian Weathering & Erosion Create the Topography of the Appalachians

Appalachian Erosional Topography Detail look at the area of the black box: Great Valley area of Central Pennsylvania

Next Week The Great Valley & Blue Ridge and the Last Continental Glacier Tramping from Alabama to Pennsylvania The last continental glacier controls everything