READING the LANDSCAPE of ESTES PARK

Jim Cole, USGS

With content from:

Bob AndersonAlan Lester

Univ. Colorado – Boulder

andBob Lillie, Oregon State

UnivMummy Range view over Marys Lake

LANDSCAPEElements and Processes

ROCK FOUNDATIONS

LANDFORMS

DRAINAGE

WEATHERING

EROSION

SEDIMENTATION

GLACIATIONView of Carter Lake west to Continental Divide

LakeEstes

GEOLOGIC BASIS of REGIONAL LANDSCAPE FEATURES

DIFFERENT ROCKS PRODUCE DIFFERENT:

LANDFORMS

SOILS

DRAINAGE PATTERNS

VEGETATION COVERS

ECOSYSTEMS/HABITATS

FAULTS and FOLDS EFFECTthe DISTRIBUTION of ROCKS

Estes Park Geologic MapDraped over Google Earth view

MOUNTAINS -WHY ARE THEY HERE?

CONSTANTLY UNDER “ATTACK”

FLOOD EROSION

LANDSLIDE / SLUMP

GLACIAL EROSION

FROST WEDGING

CHEMICAL DISSOLUTION

WIND EROSIONetc. . . . . .

GRAVITY always WINS!Lawn Lake debrisFlow - 1982

Longs Peak fromLyons

GEOLOGIC TIME SCALE – millions and millions of years

FORCES ACTING SLOWLYOVER VAST TIMESPANSCAN “MOVE MOUNTAINS”

WEATHERING – slow and steady

LUMPY RIDGE STORY

Fractures and joints make water pathways

Frost wedging

Leaching and oxidation

LICHENS – Nature’s chemical weapons factories

Corners – edges – faces

BLOCKS become KNOBS

LICHENS

WEATHERED JOINTS

CONTINENTAL CRATONDEFORMED CRATONCONTINENTAL RIFT

Laramide U

plifts

Colorado Plateau

Continental Platform

Continental Shield

Parks and Plates©2005 Robert J. Lillie

Basin and Range

NATIONALPARKS(in red)

MOUNTAINS YOUNG AND OLD

Estes Park

From: “Messages in Stone: Colorado’s Colorful Geology,” Edited by Vincent Matthews, Katie Keller-Lynn, and Betty

Fox, 2003

LARAMIDE UPLIFT:

MOUNTAIN FRONT WEST

OF DENVER

BLOCK UPLIFT of the FRONT RANGE

LONGS PEAK

BOULDER

MOUNTAINSmean

UPLIFT

PIERRE SHALE DEPOSITED IN SHALLOW SEA

NOW AT 5,000 FT AT BOULDER

NOW AT 13,000 FT AT NOKHU CRAGS

WHEN?FIRST STAGE 70 to 55 Ma

EROSION, VOLCANOES

SECOND STAGE 15 to 5 MaEROSION ON-GOING

FoothillsRolling Upland

Glaciated Highland

EP

EP

Boulder

NOKHU CRAGS

EP

Drake

MOUNTAIN VALLEYS – Some are STRAIGHT and some are TWISTY

OLDBig ThompsonRiver courseat Cedar Park

Lyons

STRAIGHT valleys (mostly)controlled by fractures

TWISTY valleys (mostly)Inherited from old surface

LakeGranby

FLOOD HAZARD inMOUNTAIN VALLEYS

SUMMER THUNDERSTORMSYSTEM STALLED OVER

THE FRONT RANGE

7.5 INCHES FELL IN ONE HOURDURING EARLY EVENING

GREATEST RAINFALL ATABOUT 8,000 ft,

NEAR TOP OF NARROW CANYON SECTION

140 LIVES LOST IN THE LOWER CANYON

July 31, 1976

DEP

POWER OF MOVING WATER

FLOODWATERS CONFINED TO NARROW CANYON

VERY LITTLE FLOODPLAIN

BEDROCK WALLS DID NOT ERODE

FLOOD CREST 10-15 FT

DRAKE 1976 DRAKE 2008

WALTONIA - Before

AFTER the FLOOD

After

GLACIATION

CLIMATE CYCLES DUE TO:

SUN-EARTH ORBIT

SOLAR ENERGY VARIATIONS

OCEAN CIRCULATION

1000 BC 2000 ADBC/AD 1000 AD

OCEAN TEMP.

ALETSCH GLACIER

ALETSCH GLACIER

GLACIAL LANDFORMS

MAJOR GLACIAL STREAMS FLOW BY GRAVITY

LATERAL AND TERMINAL MORAINES OF BOULDERY TILL

MAXIMUMICE/SNOWCOVER23,000 to 19,000YEARS AGO

North Park

Boulder

HPMP

GGCLU-shaped valley

FLAT-FLOORED PARKS FILLED WITH SAND/SILT OUTWASH

KETTLE LAKES

DOWNSTREAM END GENERALLY ABOUT 8,100 ft

FOLDED ROCKS OF THE OLD BASEMENT

BASEMENT ROCKS (GNEISSES) SLOWLY HEATED AND SQUEEZED (BURIAL)

DEFORMED AT GREAT PRESSURE AND TEMPERATURE (12 MILES)

HOT ENOUGH TO BEGIN MELTING, SO HARD ROCKS BECOME PLASTIC

GLACIERS ALSO FOLD BY SLOW, STEADY FLOW (SHEARING, MELTING, RECRYSTALLIZING)

ABOUT 1,750 MILLION YEARS AGO

ZIG-ZAG FOLDSIN GNEISS

MALASPINAGLACIER,ALASKA

WHITE BLOBS =MELTED ROCK

WATER in the WESTERN UNITED STATES

RAINFALL MUCH LESS WEST OF 100th MERIDIAN

SNOWPACK NECESSARY FOR SUMMER IRRIGATION

“FIRST IN USE-FIRST IN RIGHT”

NEED FOR FEDERAL CAPITAL = COMPROMISES!

MARYS LAKEPENSTOCKS

COLORADO-BIG THOMPSON PROJECT