Proposal
ABSTRACT
The Hopi Buttes volcanic field is located in Navajo Nation, Arizona. It is found southeast of the headwaters of the Colorado River and the mouth of the Grand Canyon, within the Bidahochi Basin. Hopi Buttes is home to over 300 maars, along with diatremes, tuff rings, and scoria cones (Dallegge et. al. 2001). These eruptions are phreatomagmatic, forming from the interaction of magma with water. Maars result from magma mixing with groundwater while tuff rings form through the eruption of magma with a water source.
Many have suggested a shallow lake, or playa, environment within the Bidahochi basin. One such evidence is the three main members of the Bidahochi Formation. The middle mafic member, related to the Hopi Buttes volcanoes, is between two sedimentary layers. These lower and upper members contain claystones, mudstones, sandstones, and other sediments that suggest lacustrine and/or fluvial deposition (Douglas et. al. 2020). Bidahochi limestone contains strontium isotope ratios consistent with the Bouse Formation limestone, believed ponded lake tufa (Austin et. al. 2020). Dallegge et. al. (2001) reports the possibility of lacustrine sediments reaching a height of 1860 m. The Hopi Buttes maars also support a lacustrine environment. The Coliseum Maar contains fossilized freshwater fish (Austin et. al. 2020). There also appears to be evidence for other lake creatures along with plants such as cattails, willows, and birches (Douglas et. al. 2020).
Looking at stratigraphic columns, volcanic materials protrude through lake sediments. There is a pattern of tuff, siltstone, pumice, sandstone, and other mafic layers alternating between the middle and upper members (Dallegge et. al. 2001). Austin et al. (2020) state that Bidahochi limestone and volcanic rocks are found interlocked surrounding the Coliseum Maar. This suggests that the maars were reacting with an aqueous environment at the surface during their eruption.
What about an overflow? Many scientists who believe that the maars and combined volcanic/lacustrine materials point to a lake also believe said lake carved out the Grand Canyon. Cited lake evidence exists all along the basin area surrounding the Colorado River’s path into the Grand Canyon. In 1858, John Newberry was the first to develop the spillover idea for Grand Canyon formation (Austin et. al. 2020). Others, such as Austin et. al. (2020), have continued his work. Blackwelder (1934) pointed out the inconsistency of the Colorado River carving out the Grand Canyon due to the lack of meanders expected for the conventional model. He also proposed that the Colorado River might have existed since the beginning of the Pleistocene (1934). This coincides with the maars’ eruptions during the late Miocene to early Pliocene, placing the Colorado River after the volcanic eruptions and potential lake overflow. Douglas et. al. (2020) used physical modeling to test the spillover theory and the appearance of the Grand Canyon after such an event. Considering the Hopi Buttes volcanic field and the possible lake evidence within the maars, it appears that the area supports a lake environment and a potential spillover event.
REFERENCES
Austin, S., E.W. Holroyd, and D.R. McQueen. 2020. Remembering spillover erosion of Grand Canyon. Answers Research Journal 13:153-188.
Blackwelder, E. 1934. Origin of the Colorado River. Bulletin of the Geological Society of America 45:551-565.
Dallegge, T.A., M.H. Ort, W.C. McIntosh, and M.E. Perkins. 2001. Age and depositional basin morphology of the Bidahochi Formation and implications for the ancestral upper Colorado River. In R.A. Young and E.E. Spamer (editors), The Colorado River: origin and evolution, pp. 47-51. Grand Canyon, AZ: Grand River Association.
Douglas, J.C., B.F Gootee, T. Dallegge, A. Jeong, Y.B. Seong, and B.Y. Yu. 2020. Evidence for the overflow origin of the Grand Canyon. Geomorphology 369, no. 107361. doi.org/10.1016/j.geomorph.2020.107361.
Keywords
Lake Bidahochi, Bidahochi Formation, Hopi Buttes volcanic field, spillover theory
Submission Type
Poster
Copyright
© 2025 Adrianna McFadden. All rights reserved.
Volcanoes in Lake Bidahochi
ABSTRACT
The Hopi Buttes volcanic field is located in Navajo Nation, Arizona. It is found southeast of the headwaters of the Colorado River and the mouth of the Grand Canyon, within the Bidahochi Basin. Hopi Buttes is home to over 300 maars, along with diatremes, tuff rings, and scoria cones (Dallegge et. al. 2001). These eruptions are phreatomagmatic, forming from the interaction of magma with water. Maars result from magma mixing with groundwater while tuff rings form through the eruption of magma with a water source.
Many have suggested a shallow lake, or playa, environment within the Bidahochi basin. One such evidence is the three main members of the Bidahochi Formation. The middle mafic member, related to the Hopi Buttes volcanoes, is between two sedimentary layers. These lower and upper members contain claystones, mudstones, sandstones, and other sediments that suggest lacustrine and/or fluvial deposition (Douglas et. al. 2020). Bidahochi limestone contains strontium isotope ratios consistent with the Bouse Formation limestone, believed ponded lake tufa (Austin et. al. 2020). Dallegge et. al. (2001) reports the possibility of lacustrine sediments reaching a height of 1860 m. The Hopi Buttes maars also support a lacustrine environment. The Coliseum Maar contains fossilized freshwater fish (Austin et. al. 2020). There also appears to be evidence for other lake creatures along with plants such as cattails, willows, and birches (Douglas et. al. 2020).
Looking at stratigraphic columns, volcanic materials protrude through lake sediments. There is a pattern of tuff, siltstone, pumice, sandstone, and other mafic layers alternating between the middle and upper members (Dallegge et. al. 2001). Austin et al. (2020) state that Bidahochi limestone and volcanic rocks are found interlocked surrounding the Coliseum Maar. This suggests that the maars were reacting with an aqueous environment at the surface during their eruption.
What about an overflow? Many scientists who believe that the maars and combined volcanic/lacustrine materials point to a lake also believe said lake carved out the Grand Canyon. Cited lake evidence exists all along the basin area surrounding the Colorado River’s path into the Grand Canyon. In 1858, John Newberry was the first to develop the spillover idea for Grand Canyon formation (Austin et. al. 2020). Others, such as Austin et. al. (2020), have continued his work. Blackwelder (1934) pointed out the inconsistency of the Colorado River carving out the Grand Canyon due to the lack of meanders expected for the conventional model. He also proposed that the Colorado River might have existed since the beginning of the Pleistocene (1934). This coincides with the maars’ eruptions during the late Miocene to early Pliocene, placing the Colorado River after the volcanic eruptions and potential lake overflow. Douglas et. al. (2020) used physical modeling to test the spillover theory and the appearance of the Grand Canyon after such an event. Considering the Hopi Buttes volcanic field and the possible lake evidence within the maars, it appears that the area supports a lake environment and a potential spillover event.
REFERENCES
Austin, S., E.W. Holroyd, and D.R. McQueen. 2020. Remembering spillover erosion of Grand Canyon. Answers Research Journal 13:153-188.
Blackwelder, E. 1934. Origin of the Colorado River. Bulletin of the Geological Society of America 45:551-565.
Dallegge, T.A., M.H. Ort, W.C. McIntosh, and M.E. Perkins. 2001. Age and depositional basin morphology of the Bidahochi Formation and implications for the ancestral upper Colorado River. In R.A. Young and E.E. Spamer (editors), The Colorado River: origin and evolution, pp. 47-51. Grand Canyon, AZ: Grand River Association.
Douglas, J.C., B.F Gootee, T. Dallegge, A. Jeong, Y.B. Seong, and B.Y. Yu. 2020. Evidence for the overflow origin of the Grand Canyon. Geomorphology 369, no. 107361. doi.org/10.1016/j.geomorph.2020.107361.