GEOLOGIC SETTING
RIVER BASIN
Tectonic Glacial Water Sediment Outlet
COLUMBIA RIVER Pacific Ocean, Glacial Flood
(INCLUDING ROCKY MTN. TRENCH, Considerable Bedrock
Active Margin, Subducting Plate, Alpine Glaciation, Lake Missoula Significant Snow- Deposits Off Coast,
SNAKE RIVER, WILLAMETTE RIVER, Control, Average
Flood Basalts Shifted Channel Floods, Bonneville Flood pack, Dryer Summers Northern Shore Current
COLUMBIA RIVER BAR & LONG Sediment Production
Dominant
BEACH)
MISSISSIPPI RIVER Passive Margin, Stable Mid- Major Glacial Meltwater Channel, Heavy Lowland Spring Large Quantities Of Fine Gulf Of Mexico, Large
(INCLUDING MISSOURI RIVER & continent Shelf, Coastal Zone Strong Impact From Low Glacial Runoff, Heavy Rainfall Sediment And Dissolved Marine Fan-delta, Westward
LOUISIANA DELTA) Sinking Sea Level At Times Solids Coastal Circulation
OHIO RIVER Stable Mid-continent, Heads In
Significant Spring Below Average Because Flows Into Mississippi
(INCLUDING TEAYS RIVER, Old Eroded Allegheny Mtns., Ice Marginal Channel Built From
Runoff, Above Of Low Elevation And River, Can Have Flood
MONONGAHELA RIVER & Crosses Stable Mid-continent Pieces Of Numerous Drainages
Average Precipitation Good Vegetative Cover Synchronization Problems
ALLEGHENY RIVER) Sedimentary Shelf
Passive Margin, Heads In Old
POTOMAC RIVER Eroded Allegheny Mtns., Crosses Originally Graded To Low Glacial Above Average
Below Average Because Atlantic Ocean, Submerged
(INCLUDING CHESAPEAKE BAY & Of Low Elevation And River Valley, Northern
Into Sinking Sedimentary Coastal Sea level Precipitation
DELMARA PENINSULA) Good Vegetative Cover Coastal Circulation.
Shelf, Impacted By A Meteor
Originates In Glacial Lake Agassiz,
Rapid Spring Lowland
RED RIVER OF THE NORTH Stable Mid-continent, Flows From Flows North Against Glacially
Snowmelt Fine Grained Derived From
Hudson Bay That Has
(INCLUDING LAKE WINNIPEG & Sedimentary Shelf OnTo Induced Crustal Rebound Centered Uplifted Over 100 Meters
Occasionally Mixed Old Glacial Lake Bed
HUDSON BAY) Continental Craton Near Hudson Bay, Stream Gradient Since The Last Glaciation
With Rain
Lowering
High Fine Sediment
RIO GRANDE RIVER Active Uplift At Head (Mtn. No Significant Glacial Impacts,
Area Arid,
Production Caused By
Gulf Of Mexico, Northeast
(INCLUDING ELEPHANT BUTTE Significantly Higher Coastal Circulation Strongly
Building), Mouth Sinking At Small Amount Of Alpine Glaciation Occasional High Intensity
RESERVOIR, RIO PUERCO & Precipitation During Influences The Stability Of
Passive Margin At Head Storms And Scant
PADRE ISLAND) Glacial Periods Padre Island
Vegetative Cover
SANTA ANA RIVER Area Arid, High Fine Sediment
Pacific Ocean, Southern
(INCLUDING SAN BERNARDINO Significantly Higher Production Caused By
Active Margin, Strike-slip Faulting Coastal Circulation
MTNS., PRADO WETLANDS, LOS No Significant Glacial Impacts Precipitation During Occasional High Intensity
Very Active Influences Huntington
ANGLES BASIN & HUNTINGTON Glacial Periods,Water Storms And Scant
Beach
BEACH) Imported Into Basin Vegetative Cover