14-19. Integrated Analysis of the Stratigraphic and Sedimentologic Record of the Origin and Evolution of the lower Colorado River
We are seeking a postdoctoral fellow to investigate the intriguing history of the lower Colorado River using detailed regional analysis of its sedimentary record. This is an excellent opportunity to combine an array of traditional and modern methods of sedimentologic, stratigraphic, and paleontologic analysis to elucidate the initiation history of one of the world’s great rivers.
The origin and geologic history of the modern course of the Colorado River through and downstream of Grand Canyon are topics of great and long-standing popular and scientific interest (e.g., Ives, 1861; Blackwelder, 1934; Longwell, 1936, 1963; Lucchitta, in Beard and others, 2011]. However, research on the river’s early history in the lower Colorado River valleys has yet to fully exploit the remarkable and well-preserved stratigraphic record of the river’s first arrival and evolution in the early Pliocene.
Two key stratigraphic units in the valleys of the lower river corridor hold the geologic record of the timing, mode, and effects of river integration and drainage basin evolution in the early Pliocene (Dorsey and others, 2007; House and others, 2008). The first is the Bouse Formation (~5 Ma), deposited in standing-water bodies that once occupied each valley (Metzger, 1968); the other is the Bullhead alluvium (~4 to 5 Ma), the first deposit(s) of the through-going Colorado River in each valley (House and others, 2005, 2008). Much previous work has focused on the nature of the Bouse Formation and its role in a continuing scientific controversy about directions and modes of river integration. There are two contrasting models: a downstream-progressing process driven by spilling of freshwater to slightly saline lakes (e.g. Spencer and Patchett, 1997; House and others, 2005); and an upstream-progressing integration influenced by sea level and tectonism (e.g., Lucchitta, 1979; Buising, 1990). Improved characterization of the depositional, paleoenvironmental, and time-directional characteristics of the Bouse and Bullhead units will contribute significantly toward assessing the primacy of either model and / or determination of the areas and times in which they may have overlapped. Thus, a well-designed stratigraphic-sedimentologic study focused on the Bouse and the Bullhead units has much potential to contribute to the resolution of the controversy.
This Research Opportunity will be integrated closely with a USGS project that is developing a geologic map of the river corridor from Hoover Dam downstream to Yuma. This pairing provides a broad platform for studying this sedimentary record using innovative combinations of traditional and modern tools and concepts: of sedimentology, stratigraphy, paleoenvironmental reconstruction, provenance, and geochronology.
Applicants may propose research that could include one or more of the following topics:
The successful candidate will have opportunities to interact with numerous USGS and university scientists and will have access to lab facilities, assistance, and mentoring essential to the project. The work will require knowledge and strong interest in fluvial, estuarine, and lacustrine sedimentary environments; sedimentary petrography; and geologic mapping. Other approaches of particular value include micropaleontology (especially palynology), paleomagnetism, and detrital zircon studies.
Beard, L.S., Karlstrom, K.E., Young, R.A., and Billingsley, G.H., eds., 2011, CRevolution 2—Origin and evolution of the Colorado River system, workshop abstracts: U.S. Geological Survey Open-File Report 2011–1210, 300 p., available at http://pubs.usgs.gov/of/2011/1210/.
Blackwelder, E., 1934, Origin of the Colorado River: Geological Society of America Bulletin, v. 45, no. 3, p. 551–566.
Buising, A. V., 1990, The Bouse Formation and bracketing units, southeastern California and western Arizona: Implications for the evolution of the proto-Gulf of California and the lower Colorado River: Journal of Geophysical Research, v. 95, no. B12, p. 20111–20, doi: 10.1029/JB095iB12p20111.
Dorsey, R.J., Fluette, A., McDougall, K., Housen, B.A., Janecke, S.U., Axen, G.J., and Shirvell, C.R., 2007, Chronology of Miocene–Pliocene deposits at Split Mountain Gorge, southern California: A record of regional tectonics and Colorado River evolution: Geology, v. 35, no. 1, p. 57–60.
Fleming, R.F., 1994, Cretaceous pollen in Pliocene rocks: Implications for Pliocene climate in the southwestern United States: Geology, v. 22, no. 9, p. 787, doi: 10.1130/0091-7613(1994)022<0787:CPIPRI>2.3.CO;2.
House, P.K., Pearthree, P.A., Howard, K.A., Bell, J.W., Perkins, M.E., Faulds, J.E., and Brock, A.L., 2005, Birth of the lower Colorado River–Stratigraphic and geomorphic evidence for its inception near the conjunction of Nevada, Arizona, and California: in Pederson, J., and Dehler, C.M., eds., Interior Western United States: Geological Society of America Field Guide, Geological Society of America, p. 357–387.
House, P.K., Pearthree, P.A., and Perkins, M.E., 2008, Stratigraphic evidence for the role of lake spillover in the inception of the lower Colorado River in southern Nevada and western Arizona, in Reheis, M.C., Hershler, R., and Miller, D.M, eds., Late Cenozoic drainage history of the southwestern Great Basin and lower Colorado River region—geologic and biotic perspectives: Geological Society of America Special Papers, v. 439, p. 335–353.
Ingersoll, R. V., Grove, M., Jacobson, C.E., Kimbrough, D.L., and Hoyt, J.F., 2013, Detrital zircons indicate no drainage link between southern California rivers and the Colorado Plateau from mid-Cretaceous through Pliocene: Geology, v. 41, no. 3, p. 311–314, doi: 10.1130/G33807.1.
Ives, J.C., 1861, Report upon the Colorado River of the west, explored in 1857 and 1858 by Lt. Joseph C. Ives: United States Government Printing Office.
Kimbrough, D.L., Grove, M., Gehrels, G.E., Mahoney, J.B., Dorsey, R.J., Howard, K.A., House, P.K., Pearthree, P.A., and Flessa, K., 2011, Detrital Zircon Record of Colorado River Integration into the Salton Trough: in Beard, L.S., Karlstrom, K.E., Young, R.A., and Billingsley, G.H., eds., CRevolution 2—Origin and evolution of the Colorado River system, workshop abstracts: U.S. Geological Survey Open-File Report 2011–1210, p. , available at http://pubs.usgs.gov/of/2011/1210/.
Kukla, G.J., 1976, Preliminary Report on magnetostratigraphic study of sediments near Blythe, California and Parker Valley, Arizona, in San Diego Gas and Electric Company: Early Site Review, Sundesert Nuclear Project, V., Appendix 2.5B, p. 186-191.
Longwell, C.R., 1936, Geology of the Boulder Reservoir floor: Geological Society of America Bulletin, v. 47, no. 9, p. 1393–1476.
Longwell, C.R., 1963, Reconnaissance geology between Lake Mead and Davis Dam, Arizona-Nevada:.U.S. Geological Survey Professional Paper 374-E, 51 p.
Lucchitta, I., 1979, Late Cenozoic uplift of the southwestern Colorado Plateau and adjacent lower Colorado River region: Tectonophysics, v. 61, no. 1–3, p. 63–95, doi: 10.1016/0040-1951(79)90292-0.
Malmon, D.V., Howard, K.A., and Hillhouse, J.W., 2011a, Observations of the Bouse Formation in Chemehuevi and Parker Valleys, California and Arizona, in Beard, L.S., Karlstrom, K.E., Young, R.A., and Billingsley, G.H., eds., CRevolution 2—Origin and evolution of the Colorado River system, workshop abstracts: U.S. Geological Survey Open-File Report 2011–1210, p. 204-205., available at http://pubs.usgs.gov/of/2011/1210/.
Malmon, D. V, Howard, K.A., House, P.K., Lundstrom, S.C., Pearthree, P.A., Sarna-Wojcicki, A., Wan, E., and Wahl, D.B., 2011b, Stratigraphy and Depositional Environments of the upper Pleistocene Chemehuevi Formation along the lower Colorado River:, U.S. Geological Survey Professional Paper 1786, 95 p.
McDougall, K., 2008, Late Neogene marine incursions and the ancestral Gulf of California: Special Papers, Geological Society of America, v. 439, p. 355.
McDougall, K.A., Poore, R.Z., and Matti, J.C., 1999, Age and paleoenvironment of the Imperial Formation near San Gorgonio Pass, Southern California: The Journal of Foraminiferal Research, v. 29, no. 1, p. 4–25.
Merriam, R., and Bandy, O.L., 1965, Source of Upper Cenozoic Sediments in Colorado Delta Region: SEPM Journal of Sedimentary Research, v. Vol. 35, no. 4, p. 911–916, doi: 10.1306/74D713A2-2B21-11D7-8648000102C1865D.
Metzger, D.G., 1968, The Bouse Formation (Pliocene) of the Parker-Blythe-Cibola area, Arizona and California: Geological Survey Research,, p. D126–D136.
Olmsted, F.H., Loeltz, O.J., and Irelan, B., 1973, Geohydrology of the Yuma area, Arizona and California: U.S. Geological Survey Professional Paper 486-H, 226 p.
Sarna-Wojcicki, A.M., Deino, A.L., Fleck, R.J., McLaughlin, R.J., Wagner, D., Wan, E., Wahl, D., Hillhouse, J.W., and Perkins, M., 2013, Age, composition, and areal distribution of the Pliocene Lawlor Tuff, and three younger Pliocene tuffs, California and Nevada, 2011, Geosphere, v. 7, no. 3, p. 599–628, doi: 10.1130/GES00609.1.
Spencer, J.E., and Patchett, P.J., 1997, Sr isotope evidence for a lacustrine origin for the upper Miocene to Pliocene Bouse Formation, lower Colorado River trough, and implications for timing of Colorado Plateau uplift: Geological Society of America Bulletin, v. 109, no. 6, p. 767–778, doi: 10.1130/0016-7606(1997)109<0767:SIEFAL>2.3.CO;2.
Proposed Duty Station: Flagstaff, AZ
Area of Ph.D.: Geology, fluvial geomorphology, sedimentology, paleoenvironments (candidates holding a Ph.D. in other disciplines, but with extensive knowledge and skills relevant to the Research Opportunity may be considered).
Qualifications: Applicants must meet one of the following qualifications - Research Geologist, Research Chemist.
(This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of theposition will be made by the Human Resources specialist).
Research advisors: Kyle House, (928) 556-7179, email@example.com.; Sue Beard, firstname.lastname@example.org.; Kristin McDougall-Reid, email@example.com; Keith Howard, firstname.lastname@example.org.
Additional collaborators: Duane Champion, Charles Powell, Elmira Wan, Dave Wahl, Phil Pearthree (Az. Geol. Survey), Rebecca Dorsey, (University of Oregon).
Human Resources Office Contact: Lisa James, (916) 278-9405, email@example.com.
|Summary of Opportunities|