Research Interests:
Paleoceanography
Marine Geology
Low-Temperature Geochemistry

Education:
B.S. (1989) University of California, Davis
M.S. (1993) University of Michigan
Ph.D. (1996) University of Michigan

Research Statement:
(1) Oceanic gas hydrates: Clathrate hydrates of gas (gas hydrates) are crystalline substances composed of water and certain gases (usually methane) that occur naturally in pore space of marine sediment. These hydrates are of interest because they represent a potential future energy resource and modulator of climate change. My research has included studies on the distribution and composition of gas hydrate in sediment columns, experimental work on the thermodynamic conditions of gas hydrate formation and dissociation, and numerical models pertaining to the release of methane into the ocean and atmosphere.
(2) Geochemical cycling during major oceanographic change: This pursuit involves the construction of chemical profiles in marine sediment across critical time intervals in the evolution of our ocean. Previous work has included trace element profiles across the Cenomanian/Turonian and Miocene/Pliocene boundaries. Currently I am working toward understanding events in the early Paleogene (Paleocene-middle Eocene) and early Aptian, times characterized by major wamrth and massive input of carbon.
(3) Sediment-hosted metalliferous ore deposits: marine sedimentary rocks are the host to large ore deposits of certain metals, including iron, manganese, vanadium and barium (e.g., ores of Fe, V, Ba). In most cases, these deposits result from the combination of unusual paleoceanographic conditions and subsequent weathering or alteration processes. My current research in this area focuses on the origin of BIF hosted iron ores and black-shale hosted vanadium ores in Australia.
(4) Mixed siliciclastic/carbonate margins: Many continental margins, both modern and ancient, receive significant amounts of terrigenous clastic and shallow marine carbonate sediment. These mixed siliciclastic/carbonate depositional systems have not been well-studied in the past. The North Queensland margin of Australia is the largest extant mixed clastic/carbonate system. Currently I am quantifying sediment deposition on this margin with the aim of establishing a flux-based model of accumulation.

Selected Publications:
Dickens, G.R. & J.M. Francis "Comment: A case for a comet impact trigger for the Paleocene/Eocene thermal maximum and carbon isotope excursion." Earth and Planetary Science Letters (2004).
Fielding, C.R., J.D. Trueman, Dickens, G.R., *M. Page "Response of a major river system to the last glacial cycle: geomorphology and internal architecture of the ancestral Burdekin River across the Great Barrier Reef shelf, northeast Australia." International Association of Sedimentologists Special Publication (2004).(In Press)
Brown, M.C., N.H.S. Oliver & Dickens, G. R. "Veins and fluid flow around the Mt. Whaleback iron ore district, eastern Hamersley Province, Western Australia." Precambrian Geology (2004).(In Revision)
Hancock, H.J.L, Dickens, G. R., C.P. Strong, C.J. Hollis & B.D. Field "Foraminiferal and carbon isotope stratigraphy through the Paleocene-Eocene transition at Dee Stream, Marlborough, New Zealand.." New Zealand Journal of Geology and Geophysics, 46 (2003): 1-19.
Webb, A.W., Dickens, G. R. & N.H.S. Oliver "From BIF to iron ore: Major element chemistry and mineralogy across the Hamersley Province, Western Australia." Chemical Geology, 197 (2003): 215-251.
Milkov, A.V., G.E. Claypool, Y.J. Lee, W. Xu, G.R. Dickens, W.S. Borowski & the ODP Leg 204 Scientific Party "In situ methane concentrations at Hydrate Ridge offshore Oregon: New constraints on the global gas hydrate inventory from an active margin." Geology, 31 (2003): 833-836.
Dunbar, G.B. & G.R. Dickens "Late Quaternary shedding of shallow marine carbonate along a tropical mixed siliciclastic-carbonate shelf: Great Barrier Reef, Australia." Sedimentology, 50 (2003): 1061-1078.
Dunbar, G.B. & G.R. Dickens "Massive siliciclastic discharge to slopes of the Great Barrier Reef Platform during sea-level transgression: New constraints from cores between 15 and 16 °S latitude." Sedimentary Geology, 162 (2003): 141-158.
Dickens, G.R. "Rethinking the global carbon cycle with a large, dynamic and microbially mediated gas hydrate capacitor." Earth and Planetary Science Letters (Frontiers), 213 (2003): 169-182.
Crouch, E.M., G.R. Dickens, H. Brinkhuis, M.P. Aubry, C.J. Hollis, K.M. Rogers & H. Visscher, 2003 "The Apectodinium acme and terrestrial discharge during the Paleocene-Eocene thermal maximum: new palynological, geochemical and calcareous nannoplankton observations at Tawanui, New Zealand." Palaeogeography, Palaeoclimatology, Palaeoecology, 194 (2003): 387-403.
Dickens, G.R., D. Schroeder, K.U. Hinrichs & the Leg 201 Scientific Party "The pressure core sampler (PCS) on Ocean Drilling Program Leg 201: General operations and gas release." Initial Reports of the Ocean Drilling Program, 201 (2003).
Page, M.C., G.R. Dickens & G.B. Dunbar "Tropical view of Quaternary sequence stratigraphy: Siliciclastic accumulation on slopes east of the Great Barrier Reef since the Last Glacial Maximum." Geology, 31 (2003): 1013-1016.
Dickens, G.R. "A methane trigger for rapid warming." Science, 299 (2003): 1017.
Fielding, C.R., J.D. Trueman, G.R. Dickens & *M. Page "Anatomy of the buried Burdekin river channel across the Great Barrier Reef shelf: How does a major river operate on a tropical mixed siliciclastic/carbonate margin during sea level lowstand." Sedimentary Geology, 157 (2003): 291-301.
Dickens, G.R., T. Fewless, E. Thomas & T.J. Bralower "Excess barite accumulation during the Paleocene/Eocene thermal maximum: Massive input of dissolved barium from seafloor gas hydrate reservoirs." Causes and Consequences of Globally Warm Climates in the Early Paleogene, Geological Society of America Special Publication, 369 (2003): 11-23.
Hancock, H.L., G. Chaproniere, Dickens, G. R. & R.A. Henderson "Early Palaeogene planktonic foraminifera and carbon isotope stratigraphy at ODP Site 762, Exmouth Plateau, Northwest Australian margin." Journal of Micropalaeontology, 21 (2002): 29-42.
Heap, A.D., Dickens, G. R., L.K. Stewart & K.J. Woolfe "Holocene storage of siliciclastic sediment around islands on the middle shelf of the Great Barrier Reef Platform, Northeast Australia." Sedimentology, 49 (2002): 603-621.
Malone, M.J., G. Claypool, J.B. Martin & Dickens, G. R. "Variable methane fluxes in shallow marine systems: The composition and origin of pore waters and authigenic carbonates on the New Jersey shelf. Marine Geology.." Marine Geology, 189 (2002): 175-196.
Grant, K.M. & Dickens, G. R. "Coupled productivity and carbon isotope records in the southwest Pacific Ocean during the late Miocene-early Pliocene biogenic bloom." Palaeoclimatology, Palaeoecology, Palaeogeography, 187 (2002): 61-82.
Hancock, H.J.L. & Dickens, G. R. "Data Report: Carbonate concentrations of Paleogene sediment at Hole 1121B, Campbell Drift.." Proceedings ODP, Scientific Reports, 181 (2002): http://www-odp.tamu.edu/publications/181_SR/204/20.
Dickens, G.R. "Data Report: Dissolved manganese concentrations in deep drill holes off New Zealand (ODP Leg 181)." Proceedings ODP, Scientific Reports, 181 (2002): http://www-odp.tamu.edu/publications/181_SR/202/20.
Dickens, G.R. "Sulfate profiles and barium fronts in sediment on the Blake Ridge: Present and past methane fluxes through a large gas hydrate reservoir." Geochimica et Cosmochimica Acta, 65 (2001): 529-543.
Dobson, D.M., G.R. Dickens & D.K. Rea "Terrigenous sedimentation on Ceara Rise: A Cenozoic record of South American orogeny and erosion." Palaeogeography, Palaeoclimatology, Palaeoecology, 165 (2001): 215-229.
Dickens, G.R. "The potential volume of oceanic methane hydrates with variable external conditions." Organic Geochemistry, 32 (2001): 1179-1193.
Dickens, G.R. "Carbon addition and removal during the late Paleocene thermal maximum: Basic theory with a preliminary treatment of the isotope record at Ocean Drilling Program Site 1051, Blake Nose." Western North Atlantic Palaeogene and Cretaceous Paleoceanography, Geological Society London Special Publication, 183 (2001): 293-306.
Heap, A.D., G.R. Dickens & L.K. Stewart "Late Holocene sediment in Nara Inlet, central Great Barrier Reef platform, Australia: sediment accumulation on the middle shelf of a tropical mixed clastic/carbonate system." Marine Geology, 176 (2001): 39-54.
Dickens, G.R. "Modeling the global carbon cycle with a gas hydrate capacitor: Significance for the Latest Paleocene thermal maximum." Natural Gas Hydrates: Occurrence, Distribution and Detection, AGU Geophysical Monograph Series, 124 (2001): 19-38.
"On the fate of past gas: what happens to methane released from a bacterially mediated gas hydrate capacitor?." Geochem. Geophys. Geosys., 2 (2001).
Dickens, G, N. Exon, D. Holdway, Y. Lafoy, J-M Auzende, G. Dunbar & R. Summons "Quaternary sediment cores from the Southern Fairway Basin on the northern Lord Howe Rise (Tasman Sea)." Australian Geological Survey Organisation Record, 31 (2001): 29 pp..

Presentations:
"Reconstructing the global carbon (and barium) cycle with gas hydrates." Woods Hole Oceanographic Institution, Geochemistry Seminar Series, Woods Hole, MA. (August 17, 2002)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." Columbia University, Palisades, NY. (February 7, 2003)
"A global carbon cycle with gas hydrate." Gordon Research Conference, Organic Geochemistry, Plymouth, NH. (August 19, 2002)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." Hobart College, Geneva, NY. (February 20, 2003)
"Reconstructing the global carbon (and barium) cycle with gas hydrates." Texas A & M Dept. of Oceanography Seminar Seriers, College Station, TX. (September 9, 2002)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." Syracuse University, Syracuse, NY. (February 8, 2003)
"Reconstructing the global carbon (and barium) cycle with gas hydrates." University of Michigan Dept. of Geological Sciences Seminar Series, Ann Arbor, MI. (September 20, 2002)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." U. Southern Mississippi, Hattiesberg, MS. (March 6, 2003)
"Reconstructing the global carbon (and barium) cycle with gas hydrates." Lawrence University (JOI/USSAC Lecture), Appleton, WI. (October 3, 2002)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." Gulf Coast Marine Laboratory, Ocean Springs, MS. (March 7, 2003)
"Naturally occurring gas hydrates." Nano-Energy Conference, Rice University. (May 2, 2003)
"Reconstructing the global carbon (and barium) cycle with gas hydrates." University of Wisconsin Dept. of Geology and Geophysics Seminar Series, Madison, WI. (October 4, 2002)
"Reconstructing the global carbon (and barium) cycle with gas hydrates." Wesleyan University, Middletown, CT. (November 18, 2002)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." Wright St. University, Dayton, OH. (May 22, 2003)
"Reconstructing the global carbon (and barium) cycle with gas hydrates." Yale University Dept. of Geology & Geophysics Lecture Series, New Haven, CT. (November 19, 2002)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." Pennsylvania State University, State College, PA. (September 8, 2003)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." University of Chicago, Chicago, IL. (October 3, 2003)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." Fugro, Houston, TX. (October 17, 2003)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." Tulane University, New Orleans, LA. (October 24, 2003)
"Rethinking the global carbon and barium cycles with a large, dynamic, and microbially mediated gas hydrate capacitor." University of California, Santa Cruz, Santa Cruz, CA. (December 5, 2003)
"A source to sink explanation for clastic sediment around islands on the middle shelf of the Great Barrier Reef Platform." American Geophysical Union (AGU) Fall Meeting, San Francisco. (December 13) With A.D. Heap, L.K. Stewart.
"Massive off-shelf siliciclastic fluxes on the northeast Australian margin during transgression." American Geophysical Union (AGU) Fall Meeting, San Francisco. (December 13) With M.C. Page.
"Environmental change at the time of the Paleocene-Eocene biotic turnover; a palynological perspective." American Geophysical Union (AGU) Fall Meeting, San Francisco. (December 12) With E.M. Crouch, H. Brinkhuis, C. Heilman-Clausen, T. Adatte, H.E. Morgans, H. Visscher.
"Modeling the potential volume of gas hydrates over time and during transient climate events (INVITED)." American Geophysical Union (AGU) Fall Meeting, San Francisco. (December 12)
"Sulfate profiles and barium fronts in sediment on the Blake Ridge: Present and past depths of anaerobic methane oxidation above a large gas hydrate reservoir." American Geophysical Union (AGU) Fall Meeting, San Francisco. (December 10)
"Stable isotopic composition of interstitial waters and authigenic carbonates, New Jersey Shelf: Origin of carbonates and implication for methane flux." American Geophysical Union (AGU) Fall Meeting, San Francisco. (December 10) With M.J. Malone, G. Claypool, J.B. Martin.
"A Paleogene world with a gas hydrate capacitor." Johns Hopkins Earth Science Lecture Series (Invited Seminar), Baltimore, Maryland. (November 9)
"A Paleogene world with a gas hydrate capacitor." Utrecht University Paleobotany Lecture Series (Invited Seminar), Utrecht, Netherlands. (October 5)
"A Paleogene world with a gas hydrate capacitor." University of Rochester Earth and Enviromental Science Seminar Series (Invited Seminar), Rochester, New York. (September 26)
"A Paleogene world with a gas hydrate capacitor." International Conference of Paleoceanography (ICP) VII (Plenary Talk - cancelled because of airplane crisis), Sapporo, Japan. (September 18) With James Zachos.
"The role of paleoenvironment in the formation of sediment-hosted metal ores: three examples from Australia." Gordon Research Conference, Inorganic Geochemistry (Invited Talk), Proctor, Academy, New Hampshire. (August 20)
"Modeling the Paleogene world with a gas hydrate capacitor." Society of Sedimentary Geologists (SEPM) Diamond Jubilee Symposium (Plenary Talk), Denver, Colorado. (June 2)
"Modeling the Paleogene world with a gas hydrate capacitor." Stanford University Ocean Seminar Series (Invited Seminar), Stanford, California. (May 30)

Editorial Positions:
Member of the Editorial Board, Geology. Geological Society of America. (2001-2005).
Associate Editor, Paleoceanography. American Geophysical Union. (2001-2004).

Theses:
Adam Webb, PhD. "Chemical and mineralogical constraints on the genesis of the giant Mt. Whaleback." (2003).(Thesis or Dissertation Director)
Carmen Fraticelli, PhD. "Eustastic and Climatic Influence on Upper Slope Depostion, Offshore Texas." (2003).(Committee Member)
Gabriel J. Bowen, PhD. "Paleogene greenhouse gas and terrestrial carbon cycle feedbacks." (2003).(Committee Member)
Jorge Lorenzon, "Member, Thesis Committee."
Lisa Oaks, "Member, Thesis Committee."

Awards:
2002/2003 Distinguished Lecturer, Joint Oceanographic Institutions. (2003).

Outreach Activities:
Invited international opponent for the doctoral defense of Erica Crouch, Utrecht University, Holland. October 5, 2001.