Most of my research has involved wind-blown sediments on the Great Plains (Quaternary) and on the Colorado Plateau (Pennsylvanian through Jurassic). My "rock" projects are focused on the Navajo and Entrada Sandstones in southern Utah. Clint Rowe and I used dip directions of the cross-strata in the Navajo in our attempt to figure out atmospheric circulation over the supercontinent Pangea during the Early Jurassic. Steep cross-strata in the Navajo that formed by dry avalanching down dune slip faces contain abundant dinosaur tracks. As these animals crossed the dunes, they generated avalanches, and then stepped on them.

Most recently, Dick Kettler, Karrie Weber, and I have been working on the iron-oxide-cemented concretions and banding in the Navajo Sandstone (Jurassic of southern Utah), the Dakota Formation (Cretaceous of eastern Nebraska), and (along with Mustafa Al Kuisi of the University of Jordan), the Umm Ishrin Formation (Cambrian of southern Jordan and Egypt). Derek Burgess did his M.S. on the Shinarump Member of the Chinle Formation (Triassic of southern Utah and northern Arizona; Burgess et al., 2016). We think the iron oxide structures are the altered remnants of precursor siderite concretions that formed in association with ancient carbon dioxide reservoirs. The oxidation of siderite took place relatively recently, during the Neogene uplift of the Colorado Plateau. These diagenetic features tell very interesting hydrogeologic, geomorphic, and geomicrobiological stories.

The Nebraska Sand Hills cover nearly one fourth of the state of Nebraska and provide some "ground truth" for interpretations of ancient wind-blown sandstones. More important, however, is their record of Quaternary climate change on the Great Plains. Recent work has shown that most of this giant dunefield--including bedforms up to 400 feet high--was active only a few thousand years ago. Jim Swinehart, recently retired from the Conservation and Survey Division of University of Nebraska, Joe Mason my students, and I have been studying the interactions of streams, dunes, and lakes on the Great Plains during the latest Pleistocene and the Holocene. The UNL Luminescence Geochronology Lab in the basement of Bessey Hall (supervised by Ron Goble and Paul Hanson) has been a real stimulus to our work in the Sand Hills. New OSL dates come directly from eolian deposits; we no longer have to rely on dating buried carbon-rich soils or peats for our chronology of drought events.

• Video- I Like the Great Plains; I Love the Sand Hills
• Video- GSA Field Trip October, 2013 (Pete Reiners, Univ. Arizona)
• Video- Geology and snacks in Southern Utah video is by Martin Pepper, main snacker/talker is Pete Reiners
• Power Point for talk: National Association for Interpreters 4/5/13; "Unmasking Nebraska's Desert in Disguise" (10.5 MB)
• Photos - Gobi Desert Dinosaurs
• Photos - Caicos Platform Carbonates
• Photos - Himalayas, Nepal--Annapurna Circuit
• Photos - Dino Eggs, Argentina
• Photos - Navajo Sandstone trace fossils
• Photos - Navajo Sandstone- Rain-Induced Slumps
• Photos - Red Chert- Canyonlands
• Photos - Dune Dams, western Sand Hills
• Photos - Bison Tracks, Nebraska Sand Hills
• Photos - Namibia Dunes and Wildlife (view in html)
• Photos - Namibia Dunes and Wildlife (download 53 MB PPT file)
• Poster - Inputs of Tephra and Sulfuric Acid to an Ancient Great Plains Playa (Oligocene of Nebraska)(2.8 MB)
• Poster - Tropical Westerlies over Pangean Sand Seas(912 KB)
• Poster - Dry-Sand Tracks in Dinosaur-Triggered Grainflows(3.9 MB PDF)
• Photos -trip to Cyprus (view in html)
• Field Trip ppt, Flash Animation

Selected Research Publications (click on title for PDF)

NEBRASKA SAND HILLS

• Mason, J.A., Swinehart, J.B., Hanson, P.R., Loope, D.B., Goble, R.J., Miao, X., and Schmeisser, R.L., 2011, Late Pleistocene dune activity on the Great Plains, USA : Quaternary Science Reviews, v. 30, p. 3858-3870 (2.2 MB)
• Schmeisser, R.L., Loope, D.B., and Mason, J.A., 2010, Modern and late Holocene wind regimes over the Great Plains (central U.S.A.) Quaternary Science Reviews, v. 29, p. 554-566 (1.4 MB)
• Schmeisser, R.L., Loope, D.B., and Wedin, D.A., 2009, Clues to the Medieval destabilization of the Nebraska Sand Hills, USA, from ancient pocket gopher burrows Palaios, v. 24, p. 809-817 (2.3 MB)
• Feng, S., Oglesby, R.J., Rowe, C.M., Loope, D.B., and Hu, Q., 2008, Atlantic and Pacific SST influences on Medieval drought in North America simulated by the Community Atmospheric Model, Journal of Geophysical Research, v. 113, D11101, doi:10.1029/2007JD009347 (1.5 MB)
• Miao, X., Mason, J.A., Swinehart, J.B., Loope, D.B., Hanson, P.R., Goble, R.J., and Liu, X., 2007, A 10,000 year record of dune activity, dust storms, and severe drought in the central Great Plains Geology, v. 35, p.119-122 (336 KB).
• Sridhar, V., Loope, D.B., Swinehart, J.B., Mason, J.A., Oglesby, R.J., and Rowe, C.M., 2006, Large Wind Shift on the Great Plains during the Medieval Warm Period: Science, v. 313, p. 345-347 (1.6 MB).
• Goble, R.J., Mason, J.A., Loope, D.B., and Swinehart, J.B., 2004, Optical and radiocarbon ages of stacked paleosols and dune sands in the Nebraska Sand Hills, USA: Quaternary Science Reviews, 23, p. 1173-1182 (572 KB)
• Mason, J.A., Swinehart, J.B., Goble, R.J., and Loope, D.B., 2004, Late-Holocene dune activity linked to hydrological drought, Nebraska Sand Hills, USA: The Holocene, v. 14, p. 209-217 (624 KB)
• Sweeney, M.R. and Loope, D.B., 2001, Dune-sourced alluvial fans of the Nebraska Sand Hills: Geomorphology. v. 38 p. 31-46. (956 KB)
• Muhs, D.R., Swinehart, J.B., Loope, D.B., Been, J. Mahan, S.A., and Bush, C.A., 2000, Geochemical evidence for an eolian sand dam across the North and South Platte Rivers in Nebraska: Quaternary Research, v. 53, p. 214-222.
• Loope, D.B., and Swinehart, J.B., 2000, Thinking Like a Dune Field: Great Plains Research, v. 10, p. 5-35. (2 MB)
• Loope, D.B., Swinehart, J.B., and Mason, J.P., 1995, Dune-dammed wetlands and buried paleovalleys of the Nebraska Sand Hills: Intrinsic vs.climatic controls on the accumulation of lake and marsh sediments: Geological Society of America Bulletin, v. 107, p. 396-406. (5.9 MB)
• Loope, D.B., 1986, Recognizing and utilizing vertebrate tracks in cross section: Cenozoic hoofprints from Nebraska: PALAIOS, v. 1, p. 141-151.(4.7 MB)

GREATER NEBRASKA

• Loope, D.B., Kettler, R.M., Weber, K.A., Hinrichs, NL.. and Burgess, D.T. , 2012 , Rinded iron-oxide concretions: Hallmarks of altered siderite masses of both early and late diagenetic origin: Sedimentology, v. 59, p. 1769-1781 (4.3 MB
• Loope, D.B., Mason, J.A., Bao, H., Kettler, R.M., and Zanner, C.W., 2005, Deformation structures and an alteration zone linked to deposition of volcanogenic sulphate in an ancient playa (Oligocene of Nebraska, USA): Sedimentology, v. 52, p. 123-139 (1.5 MB)
• Bao, H., Thiemens, M.H., Loope, D.B., and Yuan, X.-L., 2003, Sulfate oxygen-17 anomaly in an Oligocene ash bed in mid-North America: Was it the dry fogs?Geophysical Research Letters, v. 30, no. 16, 1843, doi:10.1029/2003GL016869.(2.4 MB)
• Bao, H., Thiemens, M.H., Farquhar, J., Campbell, D.A., and Loope, D.B., 2000, Anomalous 17O compositions in massive sulfate deposits on the Earth: Nature, v. 406, p. 176-178. (172 KB)
• Swinehart, J.B., and Loope, D.B., 1987, Late Cenozoic geology along the summit to museum trail, Scotts Bluff National Monument, western Nebraska, Geological Society of America Centennial Field Guide Series (North-Central Section), p. 13-18. (10 MB)

SOUTHERN UTAH

• Loope, D.B. and Burberry, C.M., 2018, Sheeting joints and polygonal patterns in the Navajo Sandstone, southern Utah: Control by rock fabric, tectonic joints, buckling, and gullying: Geosphere, v. 14, no. 4; doi: 10.1130/GES01614.1 (3 MB)
• Loope, D.B., Kettler, R.M., Murray, K., Pederson, J., and Reiners, P.W., 2016, Sandstones and Utah's canyon country: Deposition, diagenesis, exhumation, and landscape evolution: Geological Society of America Field Guide 44, p. 41-71 (4.2 MB)
• Burgess, D.T., Kettler, R.M., and Loope, D.B., 2016, The geologic context of wonderstone: A complex, outcrop-scaled pattern of iron-oxide cement: Journal of Sedimentary Research, v. 86, p. 498-511 (8 MB)
• Kettler, R.M., Loope, D.B., Weber, K.A. and Niles, P.B., 2015, Life and Liesegang: Outcrop-scale microbially induced diagenetic structures and geochemical self-organization phenomena produced by oxidation of reduced iron: Astrobiology, v. 15, no. 8, p. 616-636 (1.9 MB)
• Loope, D.B., and Kettler, R.M., 2015, The footprints of ancient CO2-driven flow systems: Ferrous carbonate concretions below bleached sandstone; Geosphere, v. 11, no. 3. (6.4 MB)
• Milan, J., Chiappe, L.M., Loope, D.B., Kirkland, J.I., and Lockley, M.G., 2015, First report on dinosaur tracks from the Burro Canyon Formation, San Juan County, Utah, USA--Evidence of a diverse, hitherto unknown Lower Cretaceous dinosaur fauna, Annales Societatis Geologorum Poloniae, v. 85, p.515-525 (860 KB)
• Loope, D.B., Goble, R.J., and Johnson, J.P.L., 2014, Prelude to Seven Slots: Filling and subsequent modification of seven broad canyons in the Navajo Sandstone, south-central Utah: in MacLean, J.S., Biek, R.F., and Huntoon, J.E., editors, Geology of Utah’s Far South: Utah Geological Association Publication 43, p. 11-24 (6.5 MB)
• Loope, D.B., Elder, J.F., Zlotnik, V.A., Kettler, R.M., and Pederson, D.T., 2013, Jurassic earthquake sequence recorded by multiple generations of sand blows, Zion National Park, Utah; Geology, v. 41, p. 1131-1134 (848 kb)
• Weber, K.A., Spanbauer, T.L., Wacey, D., Kilburn, M.R.,Loope, D.B., and Kettler,R.M .2012 , Biosignatures link microorganisms to iron mineralization in a paleoaquifer: Geology, v. 40 (8), p. 747-750 (700 KB); Cover image, Geology, August, 2012 (3.7 MB)
• Loope, D.B., Elder, J.F., and Sweeney, M.R., 2012, Downslope coarsening in aeolian grainflows of the Navajo Sandstone: Sedimentary Geology, v. 265-266, p. 156-162 (1.1 MB)
• Kettler, R.M., Loope, D.B., and Weber, K.A., 2011, Follow the water: Connecting a CO2 reservoir and bleached sandstone to iron-rich concretions in the Navajo Sandstone of south-central Utah: REPLY to COMMENT: Geology, v. 39 (11) p. E251-E252 (57 KB)
• Loope, D.B., Kettler, R.M., and Weber, K.A., 2011, Morphologic clues to the origins of iron oxide-cemented spheroids, boxworks, and pipelike concretions, Navajo Sandstone of south-central Utah, U.S.A.: Journal of Geology, v. 119, p. 505-520 (18 MB)
• Loope, D.B., Kettler, R.M., and Weber, K.A., 2010, Follow the water: Connecting a CO2 reservoir and bleached sandstone to iron-rich concretions in the Navajo Sandstone of south-central Utah, USA Geology, v. 38, no. 11, p. 999-1002 (1.7 MB) Link provided by GSA (full text); Download animation from Data Repository (swf file runs with Firefox, Flash, or Internet Explorer; 500 KB)
• Loope, D.B., Seiler, W.M., Mason, J.A., and Chan, M.A., 2008, Wind scour of Navajo Sandstone at The Wave (Central Colorado Plateau, U.S.A). Journal of Geology, v. 116, p. 173-183 (1.4 MB)
• Milan, J., Loope, D.B., and Bromley, R.G., 2008, Crouching theropod and Navahopus sauropodomorph tracks from the Early Jurassic Navajo Sandstone of USA Acta Palaeontologica Polonica, v. 53 (2), p. 197-205 (696 KB)
• Loope, D.B., 2008, Life beneath the surfaces of active Jurassic dunes: Burrows from the Entrada Sandstone of south-central Utah PALAIOS, v. 23, p. 411-419 (3.7 MB)
• Rowe, C.M., Loope, D.B., Oglesby, R.J., Van der Voo, R., and Broadwater, C.E., 2007, Inconsistencies between Pangean reconstructions and basic climate controls: Science, v. 318, p. 1284-1286 (472 KB)
• Graversen, O., Milan, J., and Loope, D.B., 2007, Dinosaur tectonics: A structural analysis of theropod undertracks with a reconstruction of theropod walking dynamcs Journal of Geology, v. 115, p. 641-654 (1.3 MB)
• Milan, J. and Loope, D.B., 2007, Preservation and erosion of theropod tracks in eolian deposits: examples from the Middle Jurassic Entrada Sandstone, Utah, U.S.A.: Journal of Geology, v. 115, p. 375-386 (1.1 MB).
• Ekdale, A.A., Bromley, R.G., and Loope, D.B., 2007, Ichnofacies of an ancient erg: A climatically influenced trace fossil association in the Jurassic Navajo Sandstone, southern Utah, USA: In: Miller, W. (editor),Trace Fossils: Concepts, Problems, Prospects, p. 562-574 (18.3 MB)
• Loope, D.B., 2006, Burrows dug by large vertebrates into rain-moistened, Middle Jurassic dune sand: Journal of Geology, v. 114, p. 753-762 (4.7 MB; see above for high-resolution, color versions of figures).
• Loope, D.B.,2006, Dry-season tracks in dinosaur-triggered grainflows: PALAIOS, v. 21, p. 132-142 (8.8 MB)
• Loope, D.B., Steiner, M.B., Rowe, C.M., and Lancaster, N., 2004, Tropical westerlies over Pangean sand seas: Sedimentology, v. 51, p. 315-322. (340 KB)
• Loope, D., Eisenberg, L., and Waiss, E., 2004, Navajo sand sea of near-equatorial Pangea: Tropical westerlies, slumps, and giant stromatolites, in Nelson, E.P. and Erslev, E.A. eds., Field Trips in the Southern Rocky Mountains, USA: Geological Society of America Field Guide 5, p. 1-13. (9.1 MB)
• Loope, D.B. and Rowe, C.M., 2003, Long-lived pluvial episodes during deposition of the Navajo Sandstone: Journal of Geology, v. 111, p. 223-232. (1.4 MB)
• Loope, D.B., Rowe, C.M., and Joeckel, R.M., 2001, Annual monsoon rains recorded by Jurassic dunes: Nature, v. 412, p. 64-66. (284 KB)
• Loope, D.B., 1988, Rhizoliths in ancient eolianites: Sedimentary Geology, v. 56, p. 301-314. (21 MB)

WYOMING

• Loope, D.B., and Secord, R., 2017, Interactions of a Paleocene river, a rising anticline, and early diagenetic concretions: Journal of Sedimentary Research, v. 87, p. 866-879 (7.3 MB)
• Kilibarda, Z. and Loope, D.B., 1997, Jurassic eolian oolite on a paleohigh in the Sundance Sea, Bighorn Basin, Wyoming: Sedimentology, v. 44, p. 391-404. (5.9 MB)
• Loope, D.B. and Abegg, F.E., 2001, Recognition and geologic preservation of ancient carbonate eolianites: SEPM Special Publication 71, p. 3-16. (7.2 MB)

ARGENTINA, MONGOLIA, CYPRUS

• Jackson, F.D., Garrido, A., Schmitt, J.G., Chiappe, L.M., Dingus, L., and Loope, D.B., 2004, Abnormal, multilayered titanosaur (Dinosauria : Sauropoda) eggs from in situ clutches at the Auca Mahuevo locality, Neuquen Province, Argentina: Journal of Vertebrate Paleontology, v. 24, p. 913-922 (716 KB)
• Chiappe, L., Dingus, L., Jackson, F., Grellet-Tinner, G., Coria, R., Clarke, J., Garrido, A., and Loope, D., 2000, Sauropod eggs and embryos from the Late Cretaceous of Patagonia: First International Symposium on Dinosaur Eggs and Babies [Isona, Spain]: Extended Abstracts, p. 23-29 (2.9 MB)
• Loope, D.B. and Dingus, L., 1999, Mud-filled Ophiomorpha from Upper Cretaceous continental redbeds of Southern Mongolia: An ichnologic clue to the origin of detrital, grain-coating clays: PALAIOS, v. 14, p. 452-459. (5.4 MB)
• Loope, D.B., Mason, J.A., and Dingus, L., 1999, Lethal sandslides from eolian dunes: Journal of Geology, v. 107, p. 707-713. (568 KB)
• Loope, D.B., Dingus, L., Swisher, C.C. III, and Minjin, C., 1998, Life and death in a Late Cretaceous dunefield, Nemegt Basin, Mongolia: Geology, v. 26, p. 27-30. (3.4 MB)
• Milan, J., Theodorou, G., Loope, D.B., Panayides, I., Clemmensen, L.B., and Gkioni, M., 2015, Vertebrate tracks in Late Pleistocene-Early Holocene (?) carbonate aeolianites, Paphos, Cypus, Annales Societatis Geologorum Poloniae, v. 85, p. 507-514 (600 KB)

Articles for a Broader Audience

• Dingus, L. and Loope, D.B., 2000, Death in the Dunes, Natural History Magazine, v. 109, no. 6, p. 50-55. (3.7 MB)
• Loope, D.B., and Rowe, C.M., 2005, Seasonal Patterns of Wind and Rain Recorded by the Navajo Sandstone, Canyon Legacy, v. 54, p. 8-12. (7.4 MB)
• Loope, D.B., and Mason, J.A., 2009, Wind erosion of the wind-deposited Navajo Sandstone, USA, Geology Today, v. 25, no. 2, p. 65-70. (3.7 MB)
• Loope, D.B., 2010, Tracks and Burrows in Jurassic Dune Deposits

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