- Introduction
- The Grand Canyon in the State of Arizona
- Scope of paper
- Investigative review of published literature
- Geologic Time
- Time as a Relative Measurement
- Time is experienced by humans through daily events.
- Geologic Time is a deeper scale of time, spanning millions of years.
- Formation of the Grand Canyon
- Geologists agree that the Grand Canyon was carved by the Colorado River.
- The oddities of the Colorado River
- The Colorado River did not divert its course through an uplifted plateau.
- The Colorado River disregards fault lines.
- The Colorado River is a small stream - how could it have carved the massive canyon?
- Elucidating the Age of the Colorado River and the Grand Canyon
- Dating Techniques
- Radioactivity was discovered in 1986 by Henri Becquerel.
- Lord Rutherford was the first to suggest that radioactive decay can be used to determine the numerical age of rocks and minerals.
- Common Radiometric Dating Methods
- Potassium-Argon (K-Ar) Clock
- Argon-Argon (40Ar/39Ar) method
- Apatite Fission Track Dating
- Uranium-Thorium/Helium ([U-Th]/He) Dating
- Reports on the Numerical Age of the Colorado River and the Grand Canyon
- The current consensus among geologists is that the Grand Canyon had developed not more than six million years ago.
- Karlstrom et al. (2007): 40Ar/39Ar dating of basalts indicated that the Grand Canyon had been carved to its present depth not more than 700 thousand years ago.
- Polyak et al. (2008): analysis of cave limestones revealed age both consistent with the consensus (0.8 to 4 million years) and above it (7.5 million and 17 million years)
- Pearthree et al. (2008) report that the two sites which yielded the values above 6 million years were not related to the development of the Grand Canyon.
- Proposed Timeline of the History of the Grand Canyon (Ranney, 2012)
- 540 to 80 million years ago: accumulation of the colorful, flat-lying strata on the Colorado Plateau
- 80 to 30 million years ago: laramide uplift and initial drainage to the northeast with a possible old Grand Canyon
- 30 to 16 million years ago: collapse of the Mogollon Highlands, development of the Chuska sand sea, and unknown drainage
- 16 to 6 million years ago: lowering of the Basin and Range relative to the Colorado Plateau with interior or reversed drainage, or both
- 6 to 4 million years ago: complete integration of the Colorado River to the Gulf of California
- 4 million years ago to the present: Recent deepening of the Grand Canyon
- Summary and Conclusion
References
Hamblin, W.K and E.C. Christiansen (2004). Earth's Dynamic Systems (10th Ed.) New Jersey: Pearson Education, Inc.
Hill, C. and S. Moshier (2009). Flood Geology and the Grand Canyon: A Critique. Perspectives on Science and Christian Faith 61(2): 99-115.
Karlstrom, K.E., Crow, R.S., Peters, L., McIntosh, W., Raucci, J., Crossey, L.J., Umhoefer, P., and N. Dunbar (2007). 40Ar/ 39Ar and field studies of Quaternary basalts in Grand Canyon and model for carving Grand Canyon: Quantifying the interaction of river incision and normal faulting across the western edge of the Colorado Plateau. Geological Society of America Bulletin 119(11-12): 1283-1312.
Karlstrom, K., Timmons, J.M., and L. Crossey (2012). Introduction to Grand Canyon Geology. Geological Society of America Special Papers 489: 1-6.
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Pearthree, P., Spencer, J.E., Faulds, J.E. and P.K. House (2008). Comment on "Age and Evolution of the Grand Canyon Revealed by U-Pb Dating of Water Table−Type Speleothems." Science 321: 1634c.
Polyak, V., Hill, C. and Y. Asmerom (2008). Age and Evolution of the Grand Canyon Revealed by U-Pb Dating of Water Table−Type Speleothems. Science 319: 1377-1379.
Ranney, W. (2012). Carving Grand Canyon: Evidence, Theories, and Mystery (2nd Ed.). Arizona: Grand Canyon Association.
Spencer, J. and P. Pearthree (2008). New data confirm young age of the Grand Canyon. Arizona Geology 38(3): 4-6.
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