north sac valley geology (bcwc)2 - butte county firefox or chrome download large pdf’s better than...
Post on 21-May-2018
216 Views
Preview:
TRANSCRIPT
DWR’s Groundwater Home Page http://www.water.ca.gov/groundwater/
• Groundwater Information Center
• Maps and Reports
Note: Firefox or Chrome download large pdf’s better than Internet Explorer
• Introduction – Quick Look at How Fast Geology Changes How long this report has been in progress. How long the overall geologic theory that explains how
the Sacramento Valley was formed has been accepted.
• Key Elements of the Report Geologic History of the Northern Sacramento
Valley – Kelly Staton
Geologic Map – Jon Mulder
Geologic Cross Sections – Debbie Spangler
The Theory of Plate Tectonics
• Provides the explanation for nearly every geologic feature visible in the NSV.
• Only widely accepted as a theory since the 1960’s.
• Geologic History of Northern Sacramento Valley ‐ Kelly Staton
• Geologic Map of the Northern Sacramento Valley – Jon Mulder
• Geologic Cross Sections depicting subsurface geology of the Northern Sacramento Valley – Debbie Spangler
Pacific Plate
Sacramento Valley (present day)
Coast Range (present day)
Sierra Nevada and Cascades (present day)
North American Plate
• Ocean shoreline transgresses and regresses
• Continued uplift of the ancestral Sierra Nevadas
• Klamath Mountains uplifted• Cascade volcanism began• Submarine valleys cut into
Great Valley Sequence
• Subduction movement switches to lateral plate movement
• Mendocino Triple Junction MTJ (boundary between Pacific, North American, and Juan de Fuca/Gorda Plates) moves northward
• San Andreas Fault Zone is formed behind the MTJ
• Marine regression causes streams draining the surrounding mountains to erode deep channels
• Lovejoy Basalt flows westward across the valley through the deep channels
• Tuscan, Tehama, and Laguna Formations are deposited
• MTJ Continues to migrate northward
• Sutter Buttes erupt• Riverbank, Modesto, and
Red Bluff formations are deposited
top related