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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