This is a comprehensive scientific investigation of the geologic history and framework of the lower Colorado River. We are using geologic mapping in combination with stratigraphic, geochronologic, and geophysical studies to develop a holistic understanding of the river’s origin, the structural history of the landscape through which it flows, and the stratigraphic and geomorphic consequences of the river’s changes in response to long and short-term changes in regional tectonics and climate.
Science Issue and Relevance:
The lower Colorado River study area includes one of the world’s most iconic landscapes (Grand Canyon) and embodies a water resource that is essential to the water and electric power requirements of more than 40 Million people in the southwestern United States.
- There is wide-reaching cultural relevance in simply explaining the Grand Canyon, and we can’t begin to do that without understanding how the lower river corridor evolved.
- Regional crustal extension and associated sedimentary deposits created the characteristics of modern-day aquifers
- Detailed geologic mapping investigations build knowledge and provide deep insights into geologic processes and related natural hazards endemic to the lower Colorado River.
- Maps of the lower Colorado River will be integrated into National geologic map datasets.
Methodology to Address Issue:
Geologic mapping is the foundational method employed in this project. Mapping is a means of documenting, synthesizing and portraying scientific observations and interpretations of geologic deposits that record important episodes and timing of geologic activity. Our project is based primarily on surficial geologic mapping and regional-scale geologic maps but, will also conduct bedrock mapping and related structural studies. Our workflow involves characterizing and portraying a complex stratigraphic record at intermediate scale (e.g., 1:100,000). This process includes new geologic mapping in addition to compilation and refinement of existing maps, using a common stratigraphic nomenclature. These efforts are rely on modern GIS technology.
Geochronologic studies will focus on the ages of key Colorado River strata and underlying bedrock units and geologic structures that have influenced the river’s evolution. Structural and stratigraphic analysis of the geologic framework of the basins that hold voluminous water resources will be critically important in coming years and decades.
Below are other science projects associated with this project.
Luminescence Dating Laboratory
Argon Geochronology Laboratory
Denver Radiogenic Isotope Lab
Western Basin & Range - Eastern California Shear Zone
USGS Tephrochronology (Tephra) Project
- Overview
This is a comprehensive scientific investigation of the geologic history and framework of the lower Colorado River. We are using geologic mapping in combination with stratigraphic, geochronologic, and geophysical studies to develop a holistic understanding of the river’s origin, the structural history of the landscape through which it flows, and the stratigraphic and geomorphic consequences of the river’s changes in response to long and short-term changes in regional tectonics and climate.
Sources/Usage: Public Domain.Deformed sediment of the Bouse Formation in Chemehuevi Valley, California. Complex deformation is a likely consequence of subaqueous mass wasting of part of a growing delta of the Colorado River. Science Issue and Relevance:
The lower Colorado River study area includes one of the world’s most iconic landscapes (Grand Canyon) and embodies a water resource that is essential to the water and electric power requirements of more than 40 Million people in the southwestern United States.
- There is wide-reaching cultural relevance in simply explaining the Grand Canyon, and we can’t begin to do that without understanding how the lower river corridor evolved.
- Regional crustal extension and associated sedimentary deposits created the characteristics of modern-day aquifers
- Detailed geologic mapping investigations build knowledge and provide deep insights into geologic processes and related natural hazards endemic to the lower Colorado River.
- Maps of the lower Colorado River will be integrated into National geologic map datasets.
Methodology to Address Issue:
Geologic mapping is the foundational method employed in this project. Mapping is a means of documenting, synthesizing and portraying scientific observations and interpretations of geologic deposits that record important episodes and timing of geologic activity. Our project is based primarily on surficial geologic mapping and regional-scale geologic maps but, will also conduct bedrock mapping and related structural studies. Our workflow involves characterizing and portraying a complex stratigraphic record at intermediate scale (e.g., 1:100,000). This process includes new geologic mapping in addition to compilation and refinement of existing maps, using a common stratigraphic nomenclature. These efforts are rely on modern GIS technology.
Sources/Usage: Public Domain.Linear tracts and small patches of well rounded and varnished pebbles and cobbles mark the traces of ancient channels, bars, and floodplain terraces of the lower Colorado River. Extremely long durations of exposure to the desert environment transform the surfaces of these deposits to flat, and tightly packed pavements of spectacularly discolored and varnished river rocks. Geochronologic studies will focus on the ages of key Colorado River strata and underlying bedrock units and geologic structures that have influenced the river’s evolution. Structural and stratigraphic analysis of the geologic framework of the basins that hold voluminous water resources will be critically important in coming years and decades.
Sources/Usage: Public Domain.Summer flash-floods can introduce large amounts, of fine reddish-orange sediment to the Colorado River with spectacular results - Science
Below are other science projects associated with this project.
Luminescence Dating LaboratoryLuminescence Dating LaboratoryArgon Geochronology LaboratoryArgon Geochronology LaboratoryDenver Radiogenic Isotope LabDenver Radiogenic Isotope LabWestern Basin & Range - Eastern California Shear Zone
The Eastern California Shear Zone (ECSZ) Mapping project, funded by the National Cooperative Geologic Mapping Program, combines surficial and bedrock geologic mapping, geophysical surveys, and high-resolution topographic data analysis with neotectonic, geomorphic, structural, volcanic, and geochronologic studies to better understand the tectonic framework and landscape evolution of the ECSZ in the...USGS Tephrochronology (Tephra) Project
Tephrochronology is the study of volcanic ash deposits, combining petrology, geochemistry, and isotopic dating methods. We use tephrochronology, along with other chronostratigraphic techniques, to (1) determine the ages of coincident deposits, and, when multiple tephra layers are present, determine the history of geologic events and rates of geologic processes; and (2) correlate sediments from... - Data
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