38 research outputs found
Recommended from our members
The Colorado Plateau Coring Project (CPCP): 100 Million Years of Earth System History
Lasting over 100 million years, the early Mesozoic (252 to 145 Ma) is punctuated by two of the five major mass extinctions of the Phanerozoic (Permo-Triassic and Triassic-Jurassic) plus several smaller extinction events. It witnessed the evolutionary appearance of the modem terrestrial biota including frogs, salamanders, turtles, lizards, crocodilians, dinosaurs, birds, and mammals, and spans a time of dramatic climate changes on the continents. What is arguably the richest record of these events lies in the vast (- 2.5 million km2) complex of epicontinental basins in the western part of Pangea, now largely preserved on the Colorado Plateau (Fig.l). Since the mid-19th century, classic studies of these basins, their strata, and their fossils have made this succession instrumental in framing our context of the early Mesozoic Earth system as reflected in the international literature. Despite this long and distinguished history of study of the Colorado Plateau region, striking ambiguities in temporal resolution, major uncertainties in global correlations, and significant doubts about paleolatitudinal position hamper incorporation of the huge amount of information from the region into-tests of major competing climatic, biotic, and tectonic hypotheses and a fundamental understanding of Earth system processes
Recommended from our members
Geologic Map of Petrified Forest National Park, Arizona
This geologic dataset covers the area within the boundaries of Petrified Forest National Park (PEFO), located in northeastern Arizona (Figure 1) as defined prior to the expansion approved in December of 2004 (Figure 2); much of the land in the approved expansion has not yet been acquired by the National Park Service, and is inaccessible to the public. The map is based on unpublished mapping by Billingsley (1985b), Johns (1988), Woody (2003), published mapping by Martz and Parker (2010), and new mapping. The geology of the Little Colorado River Valley in eastern Arizona, including the PEFO area (Figures 1, 2), is characterized by widespread exposures of Triassic and Jurassic terrestrial sedimentary rocks. The Upper Triassic Chinle Formation constitutes the bulk of the non-Quaternary exposures within the Park (Figure 3). The Chinle Formation unconformably overlies the Lower- Middle Triassic Moenkopi Formation. Although this latter unit is not exposed within PEFO, widespread exposures are present to the west and south in the Little Colorado River Valley.Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact [email protected]