C. Dehler - Academia.edu (original) (raw)
Papers by C. Dehler
Recent work suggests that Fe-rich, Archean-like ocean conditions returned during the Neoproterozo... more Recent work suggests that Fe-rich, Archean-like ocean conditions returned during the Neoproterozoic. This provocative finding raises a number of questions about the triggers for this transition and the geochemical and biological consequences. To better address these questions, we present a high-resolution geochemical record through the early Neoproterozoic Chuar Group. The Chuar Group is composed of more than 1500 meters of gently folded, unmetamorphosed inter-bedded fossiliferous shales and meter scale carbonate- sandstones. Focusing primarily on the shales, Fe-speciation and sulfur isotope data provide the backbone of the study. Fe-speciation data, in particular, allows for the story of Neoproterozoic ocean anoxia to be updated and extended. Interestingly, these data illustrate transitions between Fe-rich and S-rich anoxic conditions, and shed light on how these reversions behave and are initiated. Just as important as the local information gained from the Chuar sediments, these d...
Journal of the Geological Society, Feb 8, 2018
Precambrian Research, 2014
ABSTRACT The Mesoproterozoic and Neoproterozoic Pahrump Group of Death Valley, California spans c... more ABSTRACT The Mesoproterozoic and Neoproterozoic Pahrump Group of Death Valley, California spans ca. 1300-635 Ma and provides a >500 million-year record of geologic events in southwestern Laurentia. The strata analyzed include preserved sequences separated by unconformities recording syn-Rodinia basin development (Crystal Spring Formation); Rodinia stability; regional extension culminating in Neoproterozoic rifting of the Laurentian margin of Rodinia (Horse Thief Springs through Johnnie Formations); and multiple phases of glacial sedimentation and subsequent cap carbonate deposition (Kingston Peak Formation and Noonday Dolomite). U-Pb detrital zircon analyses were conducted on samples from the entire Pahrump Group and the Noonday Dolomite in the southeastern Death Valley region (20 samples, 1945 grains) to further constrain hypotheses for regional basin development during the development of the southwestern Laurentian margin. Our interpretation of provenance data expands upon and clarifies previous models defining a series of tectonostratigraphic units including: (A) the <1400 Ma basal conglomerate of the Crystal Spring Formation, comprised of metasedimentary quartzite clasts, and exhibiting a unimodal detrital zircon sample distribution at 1690 Ma with northerly source; (B) the ca. 1320-1080 Ma Crystal Spring Formation exhibiting unimodal zircon distributions derived from southerly, local Paleoproterozoic basement sources punctuated by a ca. 300 Ma duration unconformity;
The Devils Gate Limestone at Red Hill, Simpson Park Range, Eureka Co., Nevada is composed of seve... more The Devils Gate Limestone at Red Hill, Simpson Park Range, Eureka Co., Nevada is composed of several conformable transgressive sequences cropping out in a series of step-like cliffs 1--5 m high. The general sequence is as follows: (1) a 1--4 m thick in situ boundstone dominated by large, period rugosans, domical and stratiform stromatoporids and rare, 1--3 cm diameter oncolites.
71st Annual Meeting, …, 2006
Geological Society of America Bulletin, 2010
... Maximum depositional age and provenance of the Uinta Mountain Group and Big Cottonwood Format... more ... Maximum depositional age and provenance of the Uinta Mountain Group and Big Cottonwood Formation, northern Utah: Paleogeography of rifting western Laurentia. Carol M. Dehler 1 , , C. Mark Fanning 2 , Paul K. Link 3 , Esther M. Kingsbury 3 and Dan Rybczynski 1 ...
Geoarchaeology, 2008
... DOI:10.1002/gea.20240 *Corresponding author; E-mail: bonnie.pitblado@usu.edu. Page 2. volcani... more ... DOI:10.1002/gea.20240 *Corresponding author; E-mail: bonnie.pitblado@usu.edu. Page 2. volcanic (eg, obsidian) or microcrystalline (eg, chert) materials, both rock classes with tried and true, if imperfect, sourcing track records. ...
Earth and Planetary Science Letters, 2010
Earth and Planetary Science Letters, 2007
... to a close as more sophisticated interactive technologies find their way into everyday distan... more ... to a close as more sophisticated interactive technologies find their way into everyday distance education practice (Dede, 1996, Ullmer, 1994; Kozma, 1994). ... is an emerging paradigm that has been suggested as a basis for re-conceptualizing distance education (eg, Tam, 2000). ...
Earth-Science Reviews, 2014
Recent work suggests that Fe-rich, Archean-like ocean conditions returned during the Neoproterozo... more Recent work suggests that Fe-rich, Archean-like ocean conditions returned during the Neoproterozoic. This provocative finding raises a number of questions about the triggers for this transition and the geochemical and biological consequences. To better address these questions, we present a high-resolution geochemical record through the early Neoproterozoic Chuar Group. The Chuar Group is composed of more than 1500 meters of gently folded, unmetamorphosed inter-bedded fossiliferous shales and meter scale carbonate- sandstones. Focusing primarily on the shales, Fe-speciation and sulfur isotope data provide the backbone of the study. Fe-speciation data, in particular, allows for the story of Neoproterozoic ocean anoxia to be updated and extended. Interestingly, these data illustrate transitions between Fe-rich and S-rich anoxic conditions, and shed light on how these reversions behave and are initiated. Just as important as the local information gained from the Chuar sediments, these d...
Journal of the Geological Society, Feb 8, 2018
Precambrian Research, 2014
ABSTRACT The Mesoproterozoic and Neoproterozoic Pahrump Group of Death Valley, California spans c... more ABSTRACT The Mesoproterozoic and Neoproterozoic Pahrump Group of Death Valley, California spans ca. 1300-635 Ma and provides a >500 million-year record of geologic events in southwestern Laurentia. The strata analyzed include preserved sequences separated by unconformities recording syn-Rodinia basin development (Crystal Spring Formation); Rodinia stability; regional extension culminating in Neoproterozoic rifting of the Laurentian margin of Rodinia (Horse Thief Springs through Johnnie Formations); and multiple phases of glacial sedimentation and subsequent cap carbonate deposition (Kingston Peak Formation and Noonday Dolomite). U-Pb detrital zircon analyses were conducted on samples from the entire Pahrump Group and the Noonday Dolomite in the southeastern Death Valley region (20 samples, 1945 grains) to further constrain hypotheses for regional basin development during the development of the southwestern Laurentian margin. Our interpretation of provenance data expands upon and clarifies previous models defining a series of tectonostratigraphic units including: (A) the <1400 Ma basal conglomerate of the Crystal Spring Formation, comprised of metasedimentary quartzite clasts, and exhibiting a unimodal detrital zircon sample distribution at 1690 Ma with northerly source; (B) the ca. 1320-1080 Ma Crystal Spring Formation exhibiting unimodal zircon distributions derived from southerly, local Paleoproterozoic basement sources punctuated by a ca. 300 Ma duration unconformity;
The Devils Gate Limestone at Red Hill, Simpson Park Range, Eureka Co., Nevada is composed of seve... more The Devils Gate Limestone at Red Hill, Simpson Park Range, Eureka Co., Nevada is composed of several conformable transgressive sequences cropping out in a series of step-like cliffs 1--5 m high. The general sequence is as follows: (1) a 1--4 m thick in situ boundstone dominated by large, period rugosans, domical and stratiform stromatoporids and rare, 1--3 cm diameter oncolites.
71st Annual Meeting, …, 2006
Geological Society of America Bulletin, 2010
... Maximum depositional age and provenance of the Uinta Mountain Group and Big Cottonwood Format... more ... Maximum depositional age and provenance of the Uinta Mountain Group and Big Cottonwood Formation, northern Utah: Paleogeography of rifting western Laurentia. Carol M. Dehler 1 , , C. Mark Fanning 2 , Paul K. Link 3 , Esther M. Kingsbury 3 and Dan Rybczynski 1 ...
Geoarchaeology, 2008
... DOI:10.1002/gea.20240 *Corresponding author; E-mail: bonnie.pitblado@usu.edu. Page 2. volcani... more ... DOI:10.1002/gea.20240 *Corresponding author; E-mail: bonnie.pitblado@usu.edu. Page 2. volcanic (eg, obsidian) or microcrystalline (eg, chert) materials, both rock classes with tried and true, if imperfect, sourcing track records. ...
Earth and Planetary Science Letters, 2010
Earth and Planetary Science Letters, 2007
... to a close as more sophisticated interactive technologies find their way into everyday distan... more ... to a close as more sophisticated interactive technologies find their way into everyday distance education practice (Dede, 1996, Ullmer, 1994; Kozma, 1994). ... is an emerging paradigm that has been suggested as a basis for re-conceptualizing distance education (eg, Tam, 2000). ...
Earth-Science Reviews, 2014