Transcript File
Vagabonds & Sojourners Tramping Geology The Appalachian Mountains Session 3 The Southern Appalachian Mountains: North Carolina, Tennessee, Georgia, and Alabama Remember from previous sessions: 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 Pennsylvania Unhappy “campers” in the exploration for Marcellus shale gas in Pennsylvania A new book you may or may not want to read The Quest: what’s in the 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 Remember from previous sessions: Possible Area of Human Habitation 15,000 Years Ago Pre-Clovis artifact sites 15,000 years ago Also from previous sessions: 1. mountains are created when rocky crustal plates collide and when they shear past one another 2. mountain building creates a variety of new metamorphic and igneous rocks 3. the Appalachian Mountains were modified by a continental glacier about 12,000 years ago 4. the Appalachian Mountains have exposed rocks at the surface that have shaped the history of eastern North America Rocks of the Appalachian Provinces Rocks in the Geologic Provinces of the Appalachians Allegheny Plateau Valley & Ridge Sandstones Shales Limestones Shales Schist Slate Gneiss Limestones Marble Granite Gneiss Let’s find these provinces in North Carolina A. J. Eardley, 1962,Structure Geology of North America Geologic Provinces of North Carolina Great Smoky Mountains 600 million year old sandstones & shales Triassic age red sandstones & shales and black lava basalt The Piedmont geologic province Igneous & metamorphic rocks Where do we find igneous basalt rocks? Low lands: Valleys of red sandstones & shales Ridges & domes of black lava rock (basalt) “Red sandstones & Black lava basalt rocks” Triassic Age North Carolina How old is Triassic? Appalachians formed 570,000,000 years Geologic Time: Last 570 Million Years Triassic Period Back to the red and black rocks of eastern North America Geologic Map of the USA Can you find North Carolina? Rocks at the surface below soil and vegetation Geological Map: Northeast USA “Red & Black Rocks” Triassic Age North Carolina Triassic best seen in New Jersey, so let’s look there Geologic Map of New Jersey Ridges of black basalt rocks Triassic age rocks Let’s look at the basalt ridges The Triassic Palisades in NJ Opposite New York City Geologic Cross Section: Hudson River Valley at NYC View seen on Google Earth NY New York City NJ Hudson River Very old metamorphic rocks Now that we know all about rocks, let’s begin our traverse of the Appalachians in the Blue Ridge Mountains of North Carolina Geological Provinces of the Appalachians Great Valley Focus on western North Carolina Coastal Plain Piedmont “hills” Blue Ridge Mountains Great Smoky Mountains Geologic Provinces of North Carolina Great Smoky Mountains 600 million year old sandstones & shales The Piedmont geologic province Igneous & metamorphic rocks Triassic age red sandstones & shales and black lava Basalt Blue Ridge mountains 300 million year old metamorphic rocks Focus on the Great Smoky & Blue Ridge mountains West-East Geologic Cross Section North Carolina Let’s see how the Great Smoky Mountains fit into the regional topography Tenn NC From P. B. King, 1959, The Evolution of North America Rivers & the Great Smoky Mountains How might rivers have affected the arrival of First Nation Peoples? Great Smoky Mountains Tennessee River Hammond Citation World Atlas, 1962 How might rivers channeled the arrival of First Nation Peoples? Remember the glacier 15,000 years ago Great Smoky Mountains Tennessee River Let’s see what’s interesting in the Great Smoky Mountain province Mountains might have provided a refuge away from glacial melt water Possible track of early human migration during glacial time Hammond Citation World Atlas, 1962 Let’s see what else is interesting in the Great Smoky Mountain province Visitors to the Great Smoky Mountains National Park wait for darkness, when fireflies emerge. For two weeks each June, thousands of them blink in synchrony Road Map: Western North Carolina and Eastern Tennessee What’s special in the Great Smoky Mountains in North Carolina? The Great Smoky Mountains of North Carolina Gatlinburg, Tenn. Great Smoky Mts. National Park North Carolina Ancestral home of the Eastern Cherokee Indians Up close Gatlinburg Great Smoky Mts. National Park Cherokee North Carolina Rock ages on the geologic time chart What natural resources** are found in the Great Smoky & Blue Ridge mountains? **Resource that Native Americans & Age of Blue Ridge Mts Colonial Americans might need. Appalachian geosynclinal sedimentary rocks converted into metamorphic & igneous rocks of the Blue Ridge Mountains Age of rocks Great Smoky Mts Natural Resources of North Carolina Focus on western North Carolina: Natural resources and rock types Ashville Geologic Map: Western North Carolina Natural Resources of North Carolina Focus on western North Carolina Copper could have been used by early humans Note the concentration of mineralization near the Smoky-Blue Ridge contact Metamorphic industrial materials of no value until late in the industrial age What counties have these resources? Counties in western North Carolina with commercial resources What are some of the well known places in western North Carolina? Spruce Pine Mineral District Ashville Focus on the Blue Ridge Mountains The Blue Ridge Mountain boundary with the Piedmont Province Piedmont province Ashville, the big city of the Blue Ridge Mountains Ashville and the Blue Ridge Parkway Ashville North Carolina Ashville, North Carolina Blue Ridge Mountains Ashville to Black Rock to Spruce Pine Black Mountain & Montreat Spruce Pine Montreat Black Mountain Black Mountain & Montreat, NC Blue Ridge Mountains Blue Ridge Parkway to Spruce Pine, Mitchell Co, NC: center of the Spruce Pine Mineral District Spruce Pine Up the Blue Ridge Parkway to Spruce Pine Up the Blue Ridge Parkway to Little Switzerland Little Switzerland to Spruce Pine, NC Spruce Pine & Pegmatites quarries Quarry Spruce Pine What is a pegmatite? Spruce Pine & nearby quarries A pegmatite is a very coarse-grained granite usually in veins or irregular rock masses in schists and gneisses Pegmatites are important because they often contain rare earth minerals and gemstones, such as aquamarine, tourmaline, topaz, fluorite, and apatite. They are also mined for feldspar and mica used in industrial products. Sandi in Spruce Pine, age 2 Feldspar - Feldspar was first mined in North Carolina in 1911 in the Spruce Pine district, the main feldspar-producing district in North America. Original mining was from pegmatite bodies but current mining is from alaskite,a very coarse-grained, light-colored, feldspar-quartz-muscovite rock. By-product mica and silica are also recovered. Most of the production is from mines in Mitchell County, The main uses of feldspar are in whiteware, tile, and glass fiber insulation. Feldspar is used both in the body of the ware and the glaze of ceramics Mica - Mica mining began on a large scale in western North Carolina about 1868. The area has become the most important producer of mica in the U.S. Sheet mica was the principal product for many years, but other materials have eliminated many of the uses for sheet mica. Consequently, North Carolina has not produced significant amounts of sheet mica since about 1962. Scrap mica is still produced in large quantities. Primary sources are the alaskite and pegmatites rocks that produce feldspar. North Carolina annually leads the nation in the production of scrap mica, producing about 60 percent of the total. Primary production is from Mitchell County in the Spruce Pine district, Some old, abandoned pegmatite mines http://www.geology.enr.state.nc.us/Mineral%2 0resources/mineralresources.html Today, Panning for gem stones: Little Switzerland, North Carolina Spruce Pine Why are so many pegmatites found here? Montreat Ashville Black Mountain Cross Section: Tenn-North Carolina Valley & Ridge Province Great Smoky Mts Province Blur Ridge Mountains Province Piedmont Province But why concentrated in and around Mitchell Co? Granites Natural Resources of North Carolina Why here? Note the concentration of mineralization near the Smoky-Blue Ridge contact Sierra Nevada Mountains: Melted Paleozoic Sediments Great Basin Province Sierra Nevada Province Basin & Range Province Granite Apply the Sierra Nevada model to the Blue Ridge Mountains Sierra Nevada Mountains Analog Analog Applied to Appalachia Atlantic Ocean Piedmont Province Blue Ridge Province Great Smoky Great Valley provinces Spruce Pine Pegmatites But why only here near Spruce Pine? Valley & Ridge Province Spruce Pine Mineral District; top of a granite column? Spruce Pine Pegmatites Metamorphic Rocks Today’s surface of the Blue Ridge Mountains Metamorphic Rocks What natural resources are west of Granite furnace North Carolina in Tennessee? Appalachians in Georgia Knoxville Area: Favorable natural resources for early civilizations: major river, iron, & coal Great Smoky Mountains Province Is there farming in the Tennessee River flood plain east of Knoxville? Tennessee River East of Knoxville What Native Americans lived here in the area of Knoxville? Native American Tribal Areas Up close here http://www.google.com/#sclient=psy&hl=en&rlz=1R2GPEA_en&source=hp&q=native+american +tribes&rlz=1R2GPEA_en&aq=3&aqi=g5&aql=&oq=&pbx=1&bav=on.2,or.r_gc.r_pw.&fp=c92477 5ad1dac27b&biw=1242&bih=638 Native American Tribal Lands: SE USA Spruce Pine Knoxville Georgia Back to the regional geologic map and then to Georgia Appalachians in Georgia Knoxville Area: Favorable natural resources for early civilizations: major river, iron, & coal Great Smoky Mountains Province What’s going on here in Alabama? Note: Iron but no nearby coal Georgia Major iron & coal at Birmingham Alabama Georgia Birmingham is on a river. Does it have a flood plain? Conclusion: Native Americans living in the Birmingham area had access to iron & coal but no extensive flood plain farm land. Birmingham No river flood plains What Native American tribal nation lived in the Birmingham area?. Native American Tribal Lands: SE USA Spruce Pine Knoxville Birmingham Georgia Alabama Back to the regional geologic map Review: Southern Appalachia Mountains North Carolina Alabama Georgia And next week: Virginia to New England Virginia to New England Great Valley Virginia What natural resources will we find up here in Virginia? Alabama North Carolina Georgia First, what natural resources are found in the Valley & Ridge and Cumberland Plateau provinces? First, what natural resources are found in the Valley & Ridge and Cumberland Plateau provinces? Cumberland Plateau & Valley & Ridge provinces North Carolina Southern Appalachians Coal Deposits: Eastern USA Cumberland Plateau & Valley & Ridge provinces Coal Deposits: USA Yellow=lignite Grays=bituminous Red=anthasite Cumberland Plateau & Valley & Ridge provinces Why are there some of the world’s largest coal, oil andhttp://www.eia.gov/oil_gas/rpd/shale_gas.pdf gas deposits in the western margin of the Appalachian Mountains? Origin of Coal, Oil, & Gas Deposits in Appalachia Coastal tropical swamps & marshes rich in plant debris = coal sources Land Paleo-geologic map by Eardley shows thickness of rocks 310 million years old Ocean A modern example of future sources of coal, oil, and gas Deep water, organic plankton rich shales = oil & gas sources After Eardley, 1962 Modern Example of Future Coal, Oil, & Coal Deposits** Marsh & swamp tropical muds = future coal Deep water organic rich muds = future oil & gas source rocks New Capture These subject: areas must be Stream located in the Tropics in order to be good source rocks Do you remember this slide? Whenever you find a right angle in the main Georgia course Alabama of a river; suspect a Stream Capture Appalachia is “full” of right angle rivers! Let’s see what’s going on New subject: Stream Capture Notice the two rivers Rivers of Eastern & Central USA Notice the Tennessee-Mississippi rivers Hammond Citation World Atlas, 1962 Rivers of the Southern Appalachians Tennessee River today Headwaters of the Mobile River before capture by the Tennessee River Main channel of the Mobile River before it was “beheaded” by the Tennessee River Mobile River today Hammond Citation World Atlas, 1962 Austin to Alamogordo, NM Rivers Note the “dog leg” in the Rio Grande at Big Bend Nat. Pk. Upper Rio Grande captured by the Pecos River Pecos River Rio Grande River River Capture River Capture Head-ward erosion What natural resources are essential for the development of early civilizations? Let’s look at the world’s early civilizations? Natural Resources & Early Civilizations Historically what was required? 1. Northern Temperate Zone 2. Shielded from melting continental glacier by mountain range(s) 3. Major river flood plain suitable for farming 4. Access to ores of copper, tin, &/or arsenic Bronze Age Large scale farming & metal tools and weapons 5. Iron and coal 6. Iron, coal, and oil 7. Iron, coal, oil, and uranium Iron Ages A quick review Northern Temperate Zone Eastern Hemisphere: Eurasia1. elongated west-east 2. located in Northern Temperate Zone A quick review Eastern Hemisphere: Eurasia: 1. elongated west-east 2. located in Northern Temperate Zone Africa: 1. elongated north-south 2. located in the tropical climate zone A quick review India and Africa collide with Eurasia forming west-east mountains extending from the Atlantic to the Pacific oceans A quick review Humans migrate into Eurasia “channeled” by the collision mountains African rift valleys form Human species appears A quick review Most recent continental glacier creates hostile climate for humans living north of collision mountains Humans migrate into Eurasia “channeled” by the collision mountains African rift valleys form Human species appears A quick review Most recent continental glacier creates hostile climate for humans living north of collision mountains Humans migrate into Eurasia “channeled” by the collision mountains Most favorable latitude for early human civilizations African rift valleys form Human species appears A quick review Most recent continental glacier creates hostile climate for humans living north of collision mountains Humans migrate into Eurasia “channeled” by the collision mountains Most favorable latitude for early human civilizations China: most favored geological province for early civilizations African rift valleys form Human species appears Mountain Trend, aka remnant of Tethys Seaway: 1. erosion exposes natural resource ores; Cu, Sn, & Fe and Coal 2. provides 10,000 mile long west-east avenues of commerce 3. greatest concentration of iron and coal at each end of trend 4. intermediate concentrations of Iron and Coal Most favorable latitude for early human civilizations African rift valleys form Human species appears Erosion & deposition create six major river flood plains in the most favorable latitude for early human civilizations Most favorable latitude for early human civilizations Nile Tigris Euphrates Indus Ganges Yellow Yangtze The geological province of China has most favorable natural resources for developing and maintaining major early civilizations. Yellow Yangtze Nile Tigris Euphrates Ganges Indus Natural Resources; 1. Metallic ores 2. Major river flood plains 3. Mountain shield So let’s look in North America for a major river, ores of copper and tin as well as iron, coal, & oil