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ACS-PRF grant 47346-B2 supported the completion of the following tasks during 2009-2010:

a)    Determination of trace element data related to Early Triassic paleoproductivity and paleoxygenation from one drill core in the Western Canada Sedimentary Basin (WCSB).

b)   Determination of total organic carbon (%TOC) and total carbonate carbon (%TIC) data from 8 drill cores from northwestern Alberta

c)    Presentation of those results at the Spring 2010 Cordilleran section meeting of the Geological Society of America with 3 undergraduate students as authors or coauthors and submission to the Fall 2010 annual meeting of the Geological Society of America with 2 undergraduate student collaborators as authors or co-authors.

d)   Collection of additional outcrop samples from the west-central WCSB that sampled deep-water facies (Ursula Creek locality).

e)    Completion of one undergraduate thesis (Liodas).

Much of 2009-2010 was spent collecting %TOC and %TIC data from drill core and outcrop samples.  Technical problems with the ICP-AES for much of 2009-2010 limited the amount of data that the PI and his students were able to collect, however, the PI was recently granted funds to acquire a new ICP-OES from NSF, which will allow elemental data to be collected without further technical delays.  During May 2010, the PI travelled to east-central British Columbia with an undergraduate student, Ryan Wakefield, and collected samples from the Ursula Creek section, a key deep-water locality that will allow comparison of environmental data across a broad swath of depositional environments in the WCSB.  %TOC and %TIC data from these samples will be used in Wakefield’s undergraduate thesis.   Sean Keffer was previously trained on the ICP-AES, and collected data for his thesis during the Fall of 2009 from a drill core (A8-7-85/18w6) from the Pedigree-Ring Border-Kahntah River area in the northern Peace River Basin, the central sub-basin of the WCSB.  This data will be used in Keffer’s undergraduate thesis, and will provide a means to examine temporal and spatial changes in paleoproductivity and paleoxygenation across a wide latitudinal swath of western North America during the Early Triassic.  Nate Liodas collected total organic carbon (%TOC) and total carbonate carbon (%TIC) data from samples from the same drill core as Keffer for his undergraduate thesis, which he completed in December 2009.  Keffer and Wakefield plan to complete their undergraduate theses during the Fall 2010 semester.  Wakefield presented the results of his research at the Spring 2010 Cordilleran GSA meeting; Liodas and Keffer also presented the results of their research at that meeting, and will additionally present results at the national GSA meeting in Denver in November 2010.

Trace element and %TOC and %TIC data has been collected from two outcrop localities (Opal Creek in the southernmost subbasin of the WCSB, the Spray River Basin and Cadomin in the central subbasin of the WCSB, the Peace River Basin), and from multiple drill cores from the Pedigree-Ring Border-Kahntah River area in the northern Peace River Basin.  In general, results suggest that productivity collapsed at the Permian-Triassic boundary, but recovered quickly in the Griesbachian (earliest Triassic).  Productivity remained robust through the remainder of the Early Triassic based on trace element data from Opal Creek, Cadomin, and one core (A8-7-85/18w6) from the Pedigree-Ring Border-Kahntah River area that samples sedimentary rocks deposited across the Dienerian-Smithian boundary (middle Early Triassic).  In addition, the typically organic-rich nature (typically 3-5% TOC) of shales and siltstones from other drill cores from the Pedigree-Ring Border-Kahntah River area is further evidence of a rapid, sustained recovery of primary producers following the Permian-Triassic mass extinction.  Results from Opal Creek are indicative of deposition under suboxic to anoxic conditions from the Permian –Triassic boundary through the Griesbachian, after which deposition occurred under oxic conditions for the remainder of the Early Triassic.  These results differ from the Cadomin locality where periods of enhanced paleoproductivity correlate with periods of low oxygenation across much of the Early Triassic, suggesting that productivity may have been a primary control on benthic oxygenation for this area.  Sedimentary rocks in the Cadomin area were deposited at shallower depths than those from Opal Creek or the Pedigree-Ring Border-Kahntah River area, which may reflect the Cadomin locality being closer to the locus of upwelling, or may be due to local paleobathymetric variations.  Trace element data from the Pedigree-Ring Border-Kahntah River area (from core A8-7-85/18w6) are indicative of suboxic conditions and higher primary productivity during periods of higher sea level as reflected by laminated silty shales, and deposition under oxic conditions during periods of lower sea level, as reflected by turbiditic and hummocky cross-stratified sandstones.  Overall, the data from the Pedigree-Ring Border-Kahntah River area suggests that shifts in the redoxocline closely tracked rising and falling sea levels.  Continued analysis of trace element data from samples collected elsewhere from the WCSB should shed further light on the interplay between productivity, paleoxygenation, and sea level during the post-extinction interval. 

This research has positively impacted the PI by allowing him to expand his research interests and knowledge beyond his previous expertise (primarily the sedimentology and petrography of unusual Lower Triassic carbonates) and by fostering collaborative relationships with several international colleagues (Tyler Beatty, J.-P. Zonneveld, Charles Henderson).  The undergraduate students involved with the research have learned technical and analytical skills that they would not likely have obtained otherwise, and are collecting and interpreting data related to a large, multidisciplinary problem.  In addition, the students have the opportunity to interact with other researchers, potential graduate advisors, and future employers when they present their data at national and regional meetings.