Carol M. Dehler
Department of Geology,Utah State University,  4505 Old Main Hill, Logan, Utah  84333  Carol.Dehler@usu.edu


carol mug shot


RESEARCH                TEACHING                ETC




                       

             
                                   


RESEARCH:

DISCIPLINES AND INTERESTS:  Sedimentology, stratigraphy, field mapping, petrography, stable-isotope geochemistry, diagenesis, climate, tectonics, and correlation of Neoproterozoic successions


PUBLICATIONS PEER-REVIEWED IN PRINT (students *)

Dehler, C.M., Gehrels, Porter, S.M., Heizler, M., G.E., Cox, G., Karlstrom, K.E., Crossey, L.J., and Timmons,  J.M., submitted 2016.  Correlation of the mid-Neoproterozoic Chuar Group, Uinta Mountain Group, and Pahrump Group (ChUMP strata), western U.S.:  Implications for a changing Earth System at ca. 740-780 Ma.  Geological Society of America Bulletin.  In review.

von Strandmann, P.A.P., Stüeken, E.E., Elliott, T., Poulton, S.W., Dehler, C.M., Canfield, D.E. and Catling, D.C., 2015. Selenium isotope evidence for progressive oxidation of the Neoproterozoic biosphere. Nature communications, 6. pdf

Dehler, C.M., 2014.  Advances in Neoproterozoic biostratigraphy spark new correlations and insight into evolution of life: Geology, v. 42, no. 8, p. 731-732. pdf

*Mahon, R.C., Dehler, C. M., Karlstrom, K.E., Link, P.K., Gehrels, G.E., 2014, Geochronologic and stratigraphic constraints on the Mesoproterozoic and Neoproterozoic Pahrump Group, Death Valley, CA: A record of the assembly, stability and breakup of Rodinia: GSA Bulletin, v. 126, no. 5-6, p. 652-664. pdf

Yonkee, W.A., Dehler, C.M., Link, P.K., *Balgord, E.A., *Keeley, J., *Hayes, D.S., Fanning, C.M.,  Wells, M.L., and Johnston, S.M.. 2014. Tectono-stratigraphic framework of Neoproterozoic to Cambrian strata, west-central U.S.: Protracted rifting, glaciation, and evolution of the North American Cordilleran margin: Earth Science Reviews, v. 136, p. 59-95. pdf

*Mahon, R.C., Dehler, C.M., Link, P.K., Karlstrom, K.E., Gehrels, G.G., 2014,  Detrital zircon provenance and paleogeography of the Pahrump Group and overlying strata, Death Valley, California.  Precambrian Research, v. 251, p. 102-117.  pdf

*Kingsbury-Stewart, E.M., *Osterhaut, S. L., Link, P.K., and Dehler, C.M., 2013.  Sequence stratigraphy and formalization of the middle Uinta Mountain Group (Neoproterozoic), central Uinta Mountains, Utah:  A closer look at the western Laurentian Seaway at ca. 750 Ma.  Precambrian Research, 236 (2013) 65–84. pdf

Dehler, C.M., Porter, S.M., and Timmons, J.M., 2012.  The Neoproterozoic Earth system revealed from the Chuar Group of Grand Canyon in Timmons, J.M. and Karlstrom, K.E., eds., Grand Canyon Geology:  Two Billion Years of Earth’s History:  Geological Society of America Special Paper 489,  p. 49-72. pdf

Dehler, C.M., Anderson, K., and Nagy, R., 2011, New descriptions of the cap dolostone and associated strata, Neoproterozoic Pocatello Formation, southeastern Idaho, U.S.A., in Evans, J.P., and Lee, J., eds., Geologic Field Trips to the Basin and Range, Rocky Mountains, Snake River Plain, and Terranes of the U.S. Cordillera:  Geological Society of America Field Guide 21, p. 181–192, doi:10.1130/2011.0021(08). pdf

Dehler, C.M., Fanning, C.M., Link, P.K., Kingsbury, E., Rybczynski, D., 2010.  Maximum depositional age and provenance of the Uinta Mountain Group and Big Cottonwood Formation, northern Utah:  Paleogeography of rifting western Laurentia.  Geological Society of America Bulletin, ahead of print doi:  10.1130/B30094, p. 1686-1699. pdf

Johnston, D.T., Poulton, S., Dehler, C.M., Porter, S.M., Husson, J., Canfield, D., Knoll, A.K., 2010.  An emerging picture of Neoproterozoic ocean chemistry:  Insights from the Chuar Group, Grand Canyon, U.S.A.  Earth and Planetary Science Letters, v. 290, p. 64-73. pdf

Nagy, R., Porter, S., Dehler, C.M., Shen, Y., 2009.  Biotic turnover driven by eutrophication before low-latitude glaciation.  Nature Geoscience, Letters, v. 2, p. 415-418. pdf

Pitblado, B.L., Dehler, C.M., Neff, H., Nelson, S.T. and Eggett, D., 2008.  Pilot study experiments in sourcing quartzite, Gunnison basin, Colorado.  Geoarcheology, Vol. 23, No. 6, 742-778. pdf

Pitblado, B.L., Neff, H., Nelson, S.T., Dehler, C.M., 2008.  AD-ICP-MS vs. LA-ICP-MS analysis of quartzite sources, Gunnison basin Colorado.  Current Research in the Pleistocene, v. 24, p. 133-136. pdf

Dehler, C.M., Porter, S.M., De Grey, L.D., Sprinkel, D.A., Brehm, A., 2007,  The Neoproterozoic Uinta Mountain Group revisited:  A synthesis of recent work on the Red Pine Shale and related undivided clastic strata, Northeastern Utah: in Link, P.K., and Lewis, R.S., eds., Proterozoic Geology of western North America and Siberia, Society of Sedimentary Geology Special Publication 86, p. 151-166. pdf

Pitblado, B. L. and Dehler, C.M., 2006. Sourcing quartzite from the Early Holocene Chance Gulch Site, Gunnison basin, Colorado. Current Research in the Pleistocene, v. 23, p. 1-3. pfg

Dehler, C.M., Elrick, M.E., Bloch, J.D., Karlstrom, K.E., Crossey, L.J., DesMarais, D., 2005.  High-resolution δ13C stratigraphy of the Chuar Group (~770-742 Ma), Grand Canyon:  Implications for mid-Neoproterozoic climate change, Geological Society of America Bulletin, v. 117, no. 1/2, p. 32-45. pdf

Dehler, C.M., Elrick, M.E., Karlstrom, K.E., Smith, G.A., Crossey, L.J., Timmons, J.M., 2001.  Neoproterozoic Chuar Group (~800-742 Ma), Grand Canyon:  A record of cyclic marine deposition during global cooling and supercontinent rifting.  Sedimentary Geology, v. 141-142, p. 465-499. pdf

Karlstrom, K.E., Bowring, S. A., Dehler, C.M., Knoll, A.H., DesMarais, D.J., Weil, A.B., Sharp, Z.D., Geissman, J.W., Elrick, M.B., Timmons, M.J., Crossey, L.J., Davidek, K.L., 2000.  Chuar Group of the Grand Canyon:  Record of breakup of Rodinia, associated change in the global carbon cycle, and ecosystem expansion by 740 Ma.  Geology, v. 28, no. 7, p. 619-622. pdf

Timmons, J.M., Karlstrom, K.E., Dehler, C.M., Geissman, J.W., Heizler, M.T., 2001.  Proterozoic multistage (~1.1 and ~8.0 Ga) extension in the Grand Canyon Supergroup and establishment of northwest and north-south tectonic grains in the southwestern United States.  Geological Society of America Bulletin, v. 113, no. 2, p. 163-180. pdf

 

CURRENT RESEARCH PROJECTS:
NEOPROTEROZOIC-CAMBRIAN WESTERN U.S.
OTHER RESEARCH



STUDENTS EMPLOYED:

ANDY BREHM--PETROLEUM GEOLOGIST, ANADARKO, DENVER, COLORADO
CAROLINE MYER BREHM--PETROLEUM GEOLOGIST, ANADARKO, DENVER, COLORADO
DAN RYBCZYNSKI--PETROLEUM GEOLOGIST, SOUTHWESTERN ENERGY, SPRING, TEXAS
ESTHER KINGSBURY--PRECAMBRIAN GEOLOGIST, WISCONSIN GEOLOGICAL SURVEY, MADISON, WISCONSIN
SHANNON OSTERHAUT--GEOLOGIST, PIONEER NATURAL RESOURCES, DALLAS/FORTWORTH, TEXAS
DAWN HAYES--PETROLEUM GEOLOGIST, ANADARKO, HOUSTON, TEXAS

CURRENT STUDENTS:

ABIGAIL BULLARD (MS)--Testing the ChUMP hypothesis with ID-TIMS
ERIN LATHROP (MS)--
The Mesoproterozoic carbon cycle as recorded in the 1.252 Ma Bass Formation, Grand Canyon
WESTON MARTIN (MS)  Subsurface and source rock analysis of the Chuar and Uinta Mountain groups of the southwestern US
KATHERINE PAUKERT (MS)  C-isotope stratigraphy of the Visingso Group, southern Sweden
MIKAELA PULSIPHER (BS)  Detrital zircon geochronology of the VIsingso Group, southern Sweden
FALLON ROWE (BS)
Detrital zircon geochronology of the VIsingso Group, southern Sweden




splitNEOPROTEROZOIC WESTERN U.S.split






carol jakes the red castle fm






Jaking the Red Castle Formation, High Uintas (left).  Carrying samples out of the Uintas with help from Thomas and Sonny the llamas.  Kings Peak, highest peak in Utah, on skyline (right).












splitNEOPROTEROZOIC UINTA MOUNTAIN GROUP, UTAH AND COLORADO

The Uinta Mountain Group(UMG)  is an amazingly understudied, 4-7 km thick succession of newly dated Proterozoic strata.  U-Pb analyses on detrital zircons has revealed a maximum depositional age of 766 Ma (Fanning and Dehler, 2005). Therefore, the UMG correlates to other dated Neoproterozoic successions in the western U.S. such as the Chuar Group.   Ongoing research in the western Uintas is focused on the Red Pine Shale--an organic-rich shale sequence (TOC)>6%).  These rocks are amenable to chemostratigraphic analyses (on organic carbon) and a detailed C-isotope curve has been generated for about 1000 m of this unit.  More traditional stratigraphic and sedimentologic studies are also underway --this unit has not been thoroughly described and paleoenvironmental interpretations remain controversial.  Correlative(?) strata on the eastern side of the range are very different and we (me and students) hypothesize that the UMG in this area represents 4-7000 m of braided stream and marginal marine deposition.  Mapping in the eastern UMG by students has resulted the subdivision  into formations, and sequence stratigraphic principles may be applicable.  We also hypothesize (me and Doug Sprinkel from the UGS) that the eastern UMG correlates with the units to the west (e.g., Red Pine Shale), but years of mapping will be necessary to test this.  Strata in the Kings Peak area in the central part of the range is amenable to sequence stratigraphy and will help to test this hypothesis.

Photo to left:  Typical outcrop of the eastern UMG (braided stream deposits).  Bushes are ~ 1 m tall.



                                                                                            






Photo to right:  Interbedded organic-rich shales and cross-bedded sandstones of the Red Pine Shale, central Uinta Mountains.  Susannah Porter for scale. 










Photo below:  Facies change in the Jesse Ewing Canyon Formation:
Neoproterozoic fan delta complex!
Laura DeGrey for scale.


jesse ewing can fm








Photomicrograph to right (2.5X):  Typical quartz arenite in the eastern Uinta Mountain Group.  
That's right, much of this Precambrian unit is NOT quartzite, but simply a well cemented sandstone.










danthe outlaw

Above:  Dan Rybczynski in his map area near the type section of the new 'formation of Outlaw Trail', northeastern Utah.



splitCHUAR GROUP--NEOPROTEROZOIC RECORD OF THE GRAND CANYON AREA


 Conclusions of this work reveal large-scale C-isotope shifts in organic and carbonate carbon.  These shifts coincide with lithostratigraphic and shale geochemical data and the combined datasets (see below) suggest that climate control was a player for the C-isotopic variability.  This is significant when considering the age of the Chuar Group (>742 Ma) and how it may be coeval or precursory to global-scale glaciations.  See Karlstrom et al, 2000, Porter and Knoll, 2000; Dehler et al, 2001; Timmons et al., 2001, Dehler et al., 2005; Dehler et al., 2012 for more information.  Research on this amazing unit continues.


 





 




Figure to left:  Multiple  datasets collectively indicate climate as a control on the carbon cycle in the mid-Neoproterozoic (see Dehler et al., 2005, GSAB)

    






     
 


Photo to right:  The Jupiter and Carbon Canyon members of the Chuar Group, ~400 m in view.  
Sweet strata!














Photo to left:  The "brain bed"--complex stromatolites often referred to as Baicalia or Boxonia.  Note the intimate relationship with variegated siliclastic shale.  These microbial buildups likely grew when climate was dryer and sea level was relatively lower (and there was more glacial ice on the planet).  See Dehler et al., 2001 for reasoning.
.












Photo to right:  Meter-scale cycles in the Carbon Canyon Member of the Chuar Group,
interpreted to be glacioeustatic.  See Dehler et al., 2001
.



 







Photo to left:  The Sixtymile Formation unconformably overlies the Chuar Group.  
At least the upper part of this unit is now known to be Cambrian!  







splitPAHRUMP GROUP--NEOPROTEROZOIC RECORD OF THE EASTERN MOJAVE DESERT


Got a sample!  Is this the same one I sampled before and it is actually Tertiary?




splitChUMP HYPOTHESIS (Chuar-Uinta Mountain-Pahrump groups).
This idea has been proposed by many workers.  Recent detailed work on all three of these successions will allow testing the idea that the Chuar, Uinta Mountain, and Pahrump groups, are, atleast in part, correlative and were part of a western Interior  Seaway in the Neoproterozoic. (George Gehrels, Susannah Porter, Karl Karlstrom, Matt Heizler, Alan Rooney, Mike Timmons, Laura Crossey, Grant Cox)  These projects focus on mid- to late Neoproterozoic strata and their implications for global paleoclimate, regional tectonics, ocean geochemistry, and correlation. 



 
splitOTHER RESEARCH:

split Taking the ChUMP hypothesis to another paleocontinent.  Study of the Neoproterozoic Visingso Group in southern Sweden.  We have collected preliminary stratigraphic, stratigraphic, and paleontological samples towards characterizing this poorly understood unit. (with Susannah Porter, Alex Zumberg, Alan Rooney, Noah Planavsky, student Katherine Paukert)

split Correlation of mid- to late Proterozoic deposits in Utah and Idaho.  The goal here is to answer questions about the style and timing of the rifting of the western Laurentian margin.  This project will also address the timing and style of glaciations during this time, and test the snowball Earth hypothesis.

In this picture (looking west on Antelope Island into the Great Salt Lake) we are all sitting on the same dropstone
within the Mineral Fork Formation.

split Paleoecology and the carbon cycle prior to the Sturtian glaciation.  Susannah Porter and I are looking at fossil and stratigraphic data from mid-Neoproterozoic units to try and understand the cause(s) for ensuing low-latitude glaciations.


Vase-shaped microfossil from the middle Neoproterozoic Horse Thief Springs Fm, Kingston Range, CA.  
The geologic community is optimistic about using this group of microfossils (thought to be testate amoebae)
as not only an environmental indicator, but also an index fossil for ca. 750 Ma.
 

split Detrital zircon geochronology of the southern Congo Margin from ca. 800 Ma to ca. 500 Ma.  We have collected and run samples to characterize the rift history of Rodinia and the almalgamation of the Gondwana. (with Mary Hubbard and Dave Foster).


Watch out for the camelthorn!
split Neoproterozoic-Cambrian stratigraphy and paleontology of the Geertsen Fm and overlying units. (with Mike Strange and Steve Reynolds), northern UT.







TEACHING:


Above:  Return from Capitol Reef...time travel complete.



Current courses:
GEO2500 GEOLOGIC EXCURSIONS
GEO3200  EARTH THROUGH TIME
GEO4900 FIELD CAMP
GEO5400/6400  FACIES ANALYSIS
GEO6450/7450 DEEP TIME



Other courses taught:  Field Methods,  Earth Systems Science, Physical Geology, Sedimentology and Stratigraphy, Advanced General Geology (graduate-level), Tectonics and Sedimentation (graduate-level)




ETC: