Gary D. Johnson
Professor of Earth Sciences Emeritus
My research activity focuses on the terrestrial record of several regions of significant environmental and tectonic change. This includes both mid-Mesozoic as well as Neogene-aged sedimentary assemblages. This research has been primarily been on areas of the East African rift system, mainly in northern Kenya, as well as in the evolving Himalayan foreland basin of north India and Pakistan. New initiatives related to a variety of sedimentary geologic problems in New England and in the northern Rockies of Wyoming, as well as research into the paleontologic record of ratite bird (e.g. Struthio sp. – ostrich, and Aepyornis sp. – “elephant bird”?) evolution and distribution in Europe and Asia is the focus of current research.
The sedimentary record of cratonic basins often provides a window into the pre-orogenic and orogenic history of adjacent mountain belts. The facies character of this sedimentary fill can usually be linked to various autocyclic and allocyclic controls, but difficulties in sorting out the chronometric detail oftentimes makes for uncertain temporal relationships. Work presently being conducted on certain Mesozoic sediments of the Cordilleran foreland basin of Wyoming and Montana, and in Late Neogene sedimentary record of the Himalayan foreland basin in India and Pakistan, is focused on understanding the detail of foreland basin evolution and the sedimentological character of syn-orogenic deposition in areas where high quality chronometric control can be erected. In this research, most of the sedimentary successions are terrestrial in character, and while having a reasonably well defined vertebrate biochronology, oftentimes these successions do not permit precise temporal relationships to be defined amongst various localities and related successions. Much of this work then, is coordinated with series of collateral studies on the chronostratigraphy of these same deposits, through separate studies of their magnetic polarity stratigraphy, and in some cases their tephrochronology.
One of these current initiatives, the peritidal record of a number of marginal marine sedimentary sequences and their tidal record, is currently underway, and involves an assessment of the character of the tidal signature preserved in Champlain Sea (early Holocene) sediments of Quebec, Ontario, and northernmost New England.
Additionally, my work has increasingly focused on public service geological research and consulting, where I am closely involved with the U.S. Bureau of Land Mangement (Department of Interior) in developing educational and research protocols associated with paleontologically important public land resources in Wyoming and elsewhere. This work has also extended to assisting several natural history museums in Wyoming in outreach development.
Current contractual arrangements with the Wyoming State Geological Survey exist to develop and produce quadrangle-scale geological maps of portions of that state. To date, one map has been completed, and several additional maps, at varying scales (1:24,000; 1:100,000) are in review or in preparation.
Adams, K and G D Johnson, “Tidal? rhythmites of the Late Wisconsinan Champlain Sea,” Geological Society of America, Abstracts with Programs , vol. 38. no. 2 (2006) 29.
Adams, K. E., Johnson, G. D., and E. S. Posmentier, (2007), "Tidal record preserved in marginal sediments of the Late Wisconsinan Champlain Sea," Geological Society of America Abstracts with Programs, Vol. 39, No. 1, p. 91
Michelson, D L, E P Kvale, G D Johnson, M R King, K A Mickelson and P Getty, “Sub-aquaeous Tetrapod Swim Tracks from the Middle Jurassic: Big Horn Basin, Wyoming, USA,” Geological Society of America , Abstracts with Programs, May 23-25 2005 57th Annual Meeting, Rocky Mountain Section, vol. 37 no. 6 (2005).
Adams, K and G D Johnson, “The Parataxonomic Implications of a South Asian Ratite Record: Eggshell Morphology and Faunal Sequence,” Geological Society of America, Abstracts with Programs , Annual Meeting Nov. 7-10, 2004 vol 36. no. 5 (2004) 423.
Kvale, E P, D M Mickelson, G D Johnson, and S Hasiotis, “The History of Dinosaur Footprint Discoveries in Wyoming, with Emphasis on the Bighorn Basin,” S. G. Pemberton, (ed.) A special volume to commemorate the contributions of W.A. S. Sarjeant, Ichnos , vol. 11 (2005) 3-9.
Johnson, G D, reprinted (2008) “Geochronology: The Interpretation and Dating of the Geological Record – Introduction. Study of the Rock Record (in part),” Encyclopaedia Britannica , Macropaedia, vol. 19 (2002) 748-755.
Kvale, E.P., G.D. Johnson, D.L. Mickelson, K. Keller, L.C.Furer, and A. W. Archer, (2001). "Middle Jurassic (Bajocian and Bathonian) dinosaur megatracksites, Bighorn Basin, Wyoming, U.S.A.," Palaeos. v. 16, no. 3, pp. 233-254.
Kvale, E.P., S. T. Hasiotis, D.L. Mickelson and G.D. Johnson, (2001), "Middle and Late Jurassic dinosaur fossil-bearing horizons: Implications for dinosaur paleoecology, northeastern Bighorn Basin, Wyoming," in C.L. Hill, ed., Mesozoic and Cenozoic paleontology in the Western Plains and Rocky Mountains, Society of Vertebrate Paleontology - 61st Annual Meeting, Bozeman, MT, October, 2001, Guidebook for the field trips. Museum of the Rockies Occasional Paper No. 3, pp. 15-46.
Renshaw, C.E., Johnson, G.D. and K.F. Kvale, (2000), "A laboratory exercise on determining dinosaur speeds using dimensional analysis." Journal of Geoscience Education, v. 48, pp. 342-346.
Swierc, J. and G.D. Johnson, (1996). "A local chronostratigraphy for the Morrison Formation, northeastern Bighorn Basin, Wyoming," in C.E. Bowen, S.C. Kirkwood and T.S. Miller, eds., Resources of the Bighorn Basin. Wyoming Geological Association Guidebook (47th). pp. 315-327.
Pivnik, D.A. and G.D. Johnson, (1995). "Depositional response to Plio-Pleistocene foreland partitioning in northwest Pakistan." Geol. Soc. America Bulletin, v. 107, no. 8, pp. 895-922.
Selected works and activities
Reeder, D., G.D. Johnson and R.W. Birnie, On-demand, Geologic map of the Manderson NE Quadrangle, Big Horn Co., Wyoming, Scale: 1:24,000 (7.5 minute geological quadrangle series), Wyoming State Geological Survey, Laramie, WY.