PROJECT PROPOSAL

Colorado Plateau Drilling Project

Colorado Plateau Drilling Project

Early Mesozoic epicontinental basins of western North America contain a spectacular record of the climatic and tectonic development of north-western Pangea as well as what is arguably the world's richest and most-studied Triassic-Jurassic continental biota. Intensely studied since the mid-nineteenth century, the basins, their strata, and their fossils have stimulated hypotheses on the development of the Early Mesozoic world as reflected in the international literature. Despite this long history of research, the lack of numerical time calibration, the presence of major uncertainties in global correlations, and an absence of entire suites of environmental proxies still loom large and prevent integration of this immense environmental repository into a useful global picture. Practically insurmountable obstacles to outcrop sampling require a scientific drilling experiment to recover key sedimentary sections that will transform our understanding of the Early Mesozoic world.

The idea presented for the Colorado Plateau Drilling Project is scientifically important. To bring our insight into this critical time in Earth history to a new level, we propose the concept of the Colorado Plateau Coring Project (CPCP), an effort to recover continuous core spanning the early Mesozoic (Triassic-Jurassic) section of the Colorado Plateau and adjacent areas.

The CPCP is a proposed five-year, interdisciplinary, multi-institutional coring project designed to decipher the biotic, climatic, and tectonic evolution of the first 100 million years of the Mesozoic (Triassic and Jurassic, ~250 - 150 Ma) Earth System as expressed in epicontinental basins of the Colorado Plateau and its environs. This project is based on the results of an international workshop involving broad segments of the Earth science community held in November 2007, which provided a community-driven science and coring concept for the CPCP.

Motivating the CPCP is the need to understand the links between major events in the history of life, climate change, and Earth System crises, particularly the two major and two minor mass extinction events, the ascent of the dinosaurs, and the origin of modern biota that would be spanned by the project. The CPCP will result in a major improvement in our ability to address outstanding issues of chronology, paleogeography, paleoclimate, and biotic evolution in this sector of the Pangea supercontinent. A scientific coring program is essential because the most continuous sections in outcrop are either inaccessible in vertical cliffs or are intensely weathered and geochemically altered, making geological observations and sampling at the appropriate level of detail practically impossible (Figure 1.) Furthermore, the shallow bedding attitudes, lateral facies changes, and covered intervals compromise unambiguous superposition in surface sections over long geographic traverses.

Figure 1 - Opportunities and problems present themselves in the superb outcrops of muddy facies of the Colorado Plateau early Mesozoic showing near 100% outcrop.

This idea is original. Recent research shows that the mudstones are often bentonitic and have a partial volcanic source, which means there are datable ashes, however it also means that the outcrop surfaces present horrendous sampling problems where freshness and competency are at premium as for geochemistry or ...