Cenozoic Earth HistoryCenozoic Earth History

The Cenozoic The Cenozoic EraEra

• Spans the time from 66 Spans the time from 66 Ma until nowMa until now

• Is sub-divided into the Is sub-divided into the periods and epochsperiods and epochs

• Experienced 1 marine Experienced 1 marine transgression, the transgression, the Tejas Tejas

• Another transgression Another transgression began ~ 16,000 years began ~ 16,000 years ago ago

Geologic Provinces of North AmericaGeologic Provinces of North America

Rift Basins Rift Basins and and

Magnetic Magnetic Highs along Highs along

the East the East Coast of Coast of

North North AmericaAmerica

What do the What do the two ridges of two ridges of magnetic highs magnetic highs represent?represent?

The eastern margin of North The eastern margin of North America is America is

presently a passive continental presently a passive continental margin margin

What geologic events would suggest subduction has begun?

But ultimately oceanic crust will break along the But ultimately oceanic crust will break along the continental continental margin and subduction of Atlantic basin crust will margin and subduction of Atlantic basin crust will beginbegin

But ultimately oceanic crust will break along the But ultimately oceanic crust will break along the continental continental margin and subduction of Atlantic basin crust will margin and subduction of Atlantic basin crust will beginbegin

Geologic Provinces of the Southern Geologic Provinces of the Southern AppalachiansAppalachians

Fall ZoneFall Zone

• Comprises a thick sequence of Comprises a thick sequence of sediments deposited on top of sediments deposited on top of the Appalachian crystalline rocks the Appalachian crystalline rocks by the Zuni (Cretaceous) and by the Zuni (Cretaceous) and Tejas (Eocene) transgressionsTejas (Eocene) transgressions

• The Cretaceous and Eocene The Cretaceous and Eocene strata crop out the farthest strata crop out the farthest inlandinland

• The ACP strata are progressively The ACP strata are progressively younger and thicker toward the younger and thicker toward the coastcoast

The Atlantic Coastal PlainThe Atlantic Coastal Plain

Evolution of the Atlantic Coastal Plain Evolution of the Atlantic Coastal Plain Following Maximum Advance of the Tejas Following Maximum Advance of the Tejas

TransgressionTransgression• The Tejas Transgression began in the Paleocene, The Tejas Transgression began in the Paleocene,

peaked in the Eocenepeaked in the Eocene, having advanced as far inland , having advanced as far inland as where Augusta, Columbia, Raleigh, Richmond, and as where Augusta, Columbia, Raleigh, Richmond, and Philadelphia are now locatedPhiladelphia are now located

• As sea level receded following maximum As sea level receded following maximum transgression: transgression: – Erosion began sculpting a stair-step series of Erosion began sculpting a stair-step series of

• scarpsscarps ((paleo-shorelinespaleo-shorelines)) and and • terracesterraces ((wave-scoured sea floorwave-scoured sea floor))

– Acidic groundwater began forming numerous Acidic groundwater began forming numerous caves caves and sinkholes in the Santee limestoneand sinkholes in the Santee limestone

– Thousands of Thousands of Carolina BaysCarolina Bays were formed on the were formed on the Middle and Lower coastal plainsMiddle and Lower coastal plains

The The Atlantic Atlantic Coastal Coastal Plain Plain

Scarps and Scarps and Terraces Terraces

The ACPSandhillsThe ACPSandhills

Peachtree RockPeachtree Rock

A remnant of tidal inlet sands deposited near A remnant of tidal inlet sands deposited near Columbia during maximum advance of the Tejas Columbia during maximum advance of the Tejas TransgressionTransgression

Santee Santee LimestoneLimestone

was was deposited in deposited in deeper water deeper water

on the on the continental continental

shelf as sands shelf as sands that formed that formed Peachtree Peachtree Rock were Rock were

deposited at deposited at the coastthe coast

The core (a) The core (a) Was drilled Was drilled at Pregnallat Pregnall

Sinkholes (irregularly-shaped depressions) formed in Sinkholes (irregularly-shaped depressions) formed in Santee Limestone near Eutaw Springs, SCSantee Limestone near Eutaw Springs, SC

Sinkhole and Cave at Santee State Park, Sinkhole and Cave at Santee State Park, SCSC

A caveA cave forms as acidic water slowly dissolves limestonecidic water slowly dissolves limestone

A sinkhole forms when the roof of the cave collapsesA sinkhole forms when the roof of the cave collapsesA sinkhole forms when the roof of the cave collapsesA sinkhole forms when the roof of the cave collapses

Atlantic Coastal Atlantic Coastal Plain Arches and Plain Arches and

EmbaymentsEmbayments

The eastern margin of The eastern margin of North America has North America has been folded into a been folded into a series of NW-SE-series of NW-SE-trending arches and trending arches and embayments by embayments by tectonism associated tectonism associated with formation of the with formation of the Caribbean plate and Caribbean plate and persistent northward persistent northward movement of Cubamovement of Cuba

Fall ZoneFall Zone

Carolina Bays near Carolina Bays near Orangeburg, SCOrangeburg, SC

Carolina Bays are NW-trending oval depressions Carolina Bays are NW-trending oval depressions surrounded by a sand rim. They are found only on the surrounded by a sand rim. They are found only on the Middle and Lower Coastal Atlantic Plain Middle and Lower Coastal Atlantic Plain

The Western Margin of North AmericaThe Western Margin of North America

Continued subduction of the Continued subduction of the Farallon PlateFarallon Plate yielded yielded the:the:• Juan de Fuca and Cocos platesJuan de Fuca and Cocos plates (its Cenozoic (its Cenozoic remnants)remnants)• San Andreas fault systemSan Andreas fault system• Numerous Cordilleran accreted terranes Numerous Cordilleran accreted terranes

Accreted Accreted CordilleranCordilleran

Volcanic Volcanic Island Arc Island Arc TerranesTerranes

An eastward-advancing wave of hot mantle An eastward-advancing wave of hot mantle caused...caused...

Cretaceous-TertiaryCretaceous-TertiaryLaramide uplift Laramide uplift

of Archean crust of Archean crust that formed the that formed the Rocky MountainsRocky Mountains

Uplift of the Uplift of the Colorado PlateauColorado Plateau

Wind River Range,Wind River Range,a Laramide uplift a Laramide uplift

Extension that Extension that formed the formed the

Basin and RangeBasin and Range

E-dipping Permian (left), Triassic (red) and Jurassic E-dipping Permian (left), Triassic (red) and Jurassic (tan) sandstone beds (right) on the E Flank of the Wind (tan) sandstone beds (right) on the E Flank of the Wind

River Range (a Laramide Archean basement uplift). River Range (a Laramide Archean basement uplift). View toward the NW from Red Canyon Overlook near View toward the NW from Red Canyon Overlook near

Lander, WyomingLander, Wyoming

Oregon Oregon TrailTrail

Centers of Centers of Cenozoic Cenozoic

CordilleranCordilleran VolcanismVolcanism

Yellowstone Yellowstone hot spothot spot

Columbia plateauColumbia plateauflood basalts flood basalts

San JuanSan Juanvolcanic volcanic

fieldfield

CascadeCascadeRangeRange

ArizonaArizonavolcanic volcanic

fieldfield

Snake River Snake River PlainPlain

Columbia Plateau, Snake River Plain, and Columbia Plateau, Snake River Plain, and Yellowstone: Products of the Yellowstone Yellowstone: Products of the Yellowstone

Mantle Plume Hot SpotMantle Plume Hot Spot

Columbia River PlateauColumbia River Plateau

Northwestward movement of N. A. over the hot spot in Northwestward movement of N. A. over the hot spot in the Mid Tertiary caused eruption of the Columbia the Mid Tertiary caused eruption of the Columbia Plateau flood basalts. Then N. A. began moving toward Plateau flood basalts. Then N. A. began moving toward the SW, forming the hook-like shape of the Snake River the SW, forming the hook-like shape of the Snake River Plain flood basalts Plain flood basalts

Island Park CalderaErupted the Huckleberry

Ridge tuff 2 Ma

Henry’s Fork CalderaErupted the Mesa Falls

tuff 1.3 Ma Yellowstone CalderaErupted the Lava Creek

tuff 0.6 Ma

YellowstoYellowstonene

Calderas Calderas

Comparison of Volumes of Pyroclastic Comparison of Volumes of Pyroclastic EruptionsEruptions

Subduction of the Juan de Fuca plate along the Subduction of the Juan de Fuca plate along the Cascadia subduction zone is responsible for the Late Cascadia subduction zone is responsible for the Late Tertiary to recent volcanism of the Cascade Range Tertiary to recent volcanism of the Cascade Range volcanoes volcanoes

Cenozoic Cenozoic Volcanism Volcanism

in the in the Cascade Cascade

RangeRange

San Francisco Mountains, ArizonaSan Francisco Mountains, Arizona

Late Cenozoic volcanism formed the San Francisco Late Cenozoic volcanism formed the San Francisco MountainsMountains

Volcanism ceased ~ 1200 years agoVolcanism ceased ~ 1200 years ago

They are remnants of a stratovolcano that blew its topThey are remnants of a stratovolcano that blew its top

The The Circum-PacificCircum-Pacific and and Alpine-Himalayan Alpine-Himalayan orogenic orogenic belts, Earth’s present-day major mountain building belts, Earth’s present-day major mountain building beltsbelts

Earth’s Major Orogenic BeltsEarth’s Major Orogenic Belts

• Volcanism, seismicity, and deformation in the Alpine-Volcanism, seismicity, and deformation in the Alpine-Himalayan orogenic belt extends eastward from Himalayan orogenic belt extends eastward from Spain through the Mediterranean region into Spain through the Mediterranean region into Southeast AsiaSoutheast Asia

• The tectonism, due to The tectonism, due to collision of the Arabian, African and Indo-Australian plates with the Eurasian plate, ,

The Alpine-Himalayan Orogenic BeltThe Alpine-Himalayan Orogenic Belt

Eocene (50–40 MaEocene (50–40 Ma

Miocene (25–15 MaMiocene (25–15 Ma

caused closure of the Tethys sea

caused closure of the Tethys sea

• Is occurring in response to northward movement of the Is occurring in response to northward movement of the African and Arabian plates toward southern Europe African and Arabian plates toward southern Europe

• The convergence is causing deformation along a linear The convergence is causing deformation along a linear zone from Spain eastward through Greece and Turkey zone from Spain eastward through Greece and Turkey and along Africa's northwest coastand along Africa's northwest coast

The Alpine OrogenyThe Alpine Orogeny

Products of the Alpine Orogeny Products of the Alpine Orogeny • AlpsAlps (France, Germany, (France, Germany, Switzerland)Switzerland)• PyreneesPyrenees (Spain and France) (Spain and France)• ApenninesApennines (Italy) (Italy)

The Alps in The Alps in Southern GermanySouthern Germany

• Subduction of Mediterranean crust under Italy, Subduction of Mediterranean crust under Italy, Greece, and Turkey continues to cause volcanism and Greece, and Turkey continues to cause volcanism and seismicityseismicity

• In 1999 an earthquake killed 17,000 people in TurkeyIn 1999 an earthquake killed 17,000 people in Turkey

Italy and GreeceItaly and Greece

Mount VesuviusMount Vesuvius, Italy, has erupted , Italy, has erupted 80 times since it destroyed Pompeii80 times since it destroyed Pompeii

in A.D. 79in A.D. 79

Mount EtnaMount Etna, Sicily, is , Sicily, is Earth’s most active volcanoEarth’s most active volcano

The Mediterranean BasinThe Mediterranean Basin

Most of the water flows into the Mediterranean Sea from Most of the water flows into the Mediterranean Sea from the Atlantic Ocean through the Strait of Gibraltarthe Atlantic Ocean through the Strait of Gibraltar

Northward advance of the African plate ~ 6 Ma closed Northward advance of the African plate ~ 6 Ma closed the Strait of Gibraltar, caused the Sea to dry upthe Strait of Gibraltar, caused the Sea to dry up

When the dam broke, a colossal flood from the Atlantic When the dam broke, a colossal flood from the Atlantic ocean rushed into the basin and re-filled the seaocean rushed into the basin and re-filled the sea

• Subduction of the Cocos plate under western Central Subduction of the Cocos plate under western Central America is causing mountain-building and volcanismAmerica is causing mountain-building and volcanism

• Subduction of the Nazca plate under western South Subduction of the Nazca plate under western South America is causing mountain-building and volcanismAmerica is causing mountain-building and volcanism

• Subduction of the Pacific plate under western Asia is Subduction of the Pacific plate under western Asia is causing mountain-building and volcanism in Japan causing mountain-building and volcanism in Japan and the Philippians and the Philippians

The Circum-Pacific Orogenic BeltThe Circum-Pacific Orogenic Belt

Global Cooling and Warming Since the Global Cooling and Warming Since the ArcheanArchean

Paleogeography Paleogeography during the during the

Permian Ice AgePermian Ice Age

Global Cooling and Warming Since the Global Cooling and Warming Since the CretaceousCretaceous

Changes in Changes in Sea Surface Sea Surface TemperaturTemperatur

es Since es Since the Eocene the Eocene

HighHigh

The Pleistocene “Ice Age”

The Pleistocene “Ice Age”

Pleistocene Ice Ages and Interglacial Pleistocene Ice Ages and Interglacial IntervalsIntervals

• The Pleistocene began 1.6 Ma, ended 10,000 years agoThe Pleistocene began 1.6 Ma, ended 10,000 years ago

• Four major periods of widespread glaciation occurred, Four major periods of widespread glaciation occurred, were separated by warmer interglacial periodswere separated by warmer interglacial periods

Two Notable Pleistocene Terminal Moraines

End morainesEnd moraines

Long IslandLong Island

Cape CodCape Cod

Glacial and Glacial and Pluvial LakesPluvial Lakes

Pluvial Lake Pluvial Lake BonnevilleBonneville

Glacial Lake Glacial Lake MissoulaMissoula

Wave-cut shore lines cut Wave-cut shore lines cut by Glacial Lake Missoulaby Glacial Lake Missoula

Channeled Scablands formed Channeled Scablands formed by the Missoula floodby the Missoula flood

Great Salt Great Salt LakeLake

Pleistocene Glaciation of the Northern Pleistocene Glaciation of the Northern HemisphereHemisphere

Climate BeltsMaximum Extent of glaciation Maximum Extent of glaciation

in the Northern Hemispherein the Northern Hemisphere

Sea Level Change during the Past 20,000 Sea Level Change during the Past 20,000 YearsYears

Global warming has been Global warming has been occurring for 17,000 yearsoccurring for 17,000 years

Positions of the coastline of North America during the Ice Age and if the ice

sheets melt

What is thought to...What is thought to...

...have caused the Pleistocene Ice Age?...have caused the Pleistocene Ice Age?• Formation of Central America deflected the Gulf Formation of Central America deflected the Gulf

Stream and moist air northward, produce more snowStream and moist air northward, produce more snow• Northward movement of North America and Eurasia Northward movement of North America and Eurasia

provided more surface for snow accumulationprovided more surface for snow accumulation

...also cause/contribute to occurrence of ice ...also cause/contribute to occurrence of ice ages?ages?

• Milankovitch cycles, natural periodic changes inMilankovitch cycles, natural periodic changes in• Earth’s orbital eccentricityEarth’s orbital eccentricity • Tilt of Earth’s axisTilt of Earth’s axis • Precession of Earth’s axis, of the equinoxesPrecession of Earth’s axis, of the equinoxes

– Cause periodic changes in the amount of sunlight Cause periodic changes in the amount of sunlight at high latitudesat high latitudes

– Lead to natural periods of global cooling and Lead to natural periods of global cooling and warmingwarming

• Excessive volcanism, etc.Excessive volcanism, etc.

Milankovitch CyclesMilankovitch CyclesA change in Earth’s orbital eccentricity A change in Earth’s orbital eccentricity occurs every 100,000 yearsoccurs every 100,000 years

A 2° change in tilt of Earth’s A 2° change in tilt of Earth’s axis occurs every 41,000 yearsaxis occurs every 41,000 years

A precession of Earth’s A precession of Earth’s

axis occurs every axis occurs every

23,000 years23,000 years