EOS: Report on Workshop
Results (.pdf download)
Supplementary material to EOS report
Colorado Plateau Coring Project Workshop, Phase 2: 100 Million Years of Climatic, Tectonic, and Biotic Evolution in Continental Cores
(John Geissman et al.)
A workshop was convened in May, 2009, in Albuquerque, New Mexico, to further advance planning for the Colorado Plateau Coring Project (CPCP), based on an initial meeting in November, 2007 (Olsen et al., 2008), and identify the target site for initial coring. The giant continental and paralic epicontinental basins of the American southwest are particularly well exposed on the Colorado Plateau and its environs and contain one of the richest records of lower Mesozoic strata. This time period was punctuated by two of the major mass extinctions of the Phanerozoic and is notable by the evolutionary appearance of the modern biota, and dramatic climate changes on the continents.
Since the mid-19th century, classic studies of these basins, their strata, and their fossils have made this sequence instrumental in framing our context for the early Mesozoic world. Nonetheless, striking ambiguities in temporal resolution, uncertainties in global correlations with other early Mesozoic strata, and major doubts about latitudinal position still hamper testing of the major competing climatic, biotic, and tectonic hypotheses. A scientific drilling experiment is essential as the most continuous sections in outcrop are either inaccessible in vertical cliffs or are weathered and geochemically altered, making observations and sampling at the appropriate level of detail impossible. Furthermore, the characteristic shallow bedding attitudes in combination with facies changes compromise the ability to determine superposition in sections compiled over long geographic traverses.
Thirty seven researchers from nine countries participated in the CPCP workshop and focused their discussion on refining the initial phase of a coring plan for the American Southwest. In the 2007 CPCP workshop, participants identified five major stratigraphic packages on and near the Colorado Plateau as key coring targets: Early to Middle Triassic Moenkopi Formation, Late Triassic Chinle Group, latest Triassic to (?) Middle Jurassic Glen Canyon Group, Middle to (?) Late Jurassic San Rafael Group, and the Late Jurassic Morrison Formation. Approximate locations targeted for coring (Fig. 1, “see o-line version) involve three long (~1 km) cores and two shorter cores designed to recover the critical early Mesozoic transitions in the area. The Triassic section (Moenkopi Formation and Chinle Group) at Petrified Forest National Park, northern Arizona, was identified in this meeting as the logical initial target for coring. The planned Petrified Forest core, about 460 m in length, will provide pristine, unweathered material to allow the development of a quantitatively robust reference section where geochronologic, magnetostratigraphic, environmental, and paleontologic information can be registered to a common thickness and an unambiguous superposition of observations. Several discrete levels in this section of Triassic strata have recently yielded high precision U-Pb zircon dates and these as well as additional age determinations on the retrieved core will provide an age-calibrated chronostratigraphy for the core that can be used to address major questions concerning early Mesozoic biotic and environmental change.
The May, 2009, CPCP workshop, which included a field trip to the proposed Petrified Forest site, endorsed development of drilling proposals to be submitted to the US NSF Sedimentary Geology and Paleobiology (in August, 2009) and International Continental Drilling Program (ICDP) (in January, 2010) to support the drilling of and research on the Petrified Forest core. The workshop was supported by the ICDP and NSF (Sedimentary Geology and Paleobiology) and was hosted by the New Mexico Museum of Natural History and Science.
CPCP 2009 Additional Links