25 Volcanoes in Lake Bidahochi Adrianna McFadden | amcfadden@cedarville.edu | Department of Science and Mathematics | Cedarville University April 2025 ICC New Scholars Conference The Hopi Buttes volcanic eld 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, tu 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 tu 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 ma c 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 uvial 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 sh (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 tu , siltstone, pumice, sandstone, and other ma c 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. Abstract Conclusion What about an over ow? 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 rst 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 over ow. 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 eld and the possible lake evidence within the maars, it appears that the area supports a lake environment and a potential spillover event. • 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 over ow origin of the Grand Canyon. Geomorphology 369, no. 107361. doi.org/10.1016/j.geomorph.2020.107361. References Acknowledgements Elephant Butte, courtesy of Dr. John Whitmore Western edge of the Coliseum Diatreme looking northwest, courtesy of Dr. John Whitmore Western edge of the Coliseum Diatreme, courtesy of Dr. John Whitmore Map of the Hopi Buttes volcanic eld, retrieved from Dallegge, et. al. 2001 Stratographic column for the Bidahochi Formation, retrieved from Dallegge, et. al. 2001 I would like to thank Dr. Whitmore for his invaluable help throughout my research journey along with the rest of the geology program who aided and supported me. 2025 New Scholars McFadden, A.M. 2025. Volcanoes in Lake Bidahochi. In J.H. Whitmore (editor), Proceedings of the 2025 New Scholars International Conference on Creationism, pp. 24-25. Cedarville, Ohio: Cedarville University International Conference on Creationism [poster presentation]. New Scholars 2025
RkJQdWJsaXNoZXIy MTM4ODY=