| Date: | Tuesday, March 2, 8:00 pm (dinner 7:00 pm) |
| Topic: | Ancient Landscapes of the American Southwest |
| Speaker: |
Wayne Ranney, geologist, author, supported by the Arizona Humanities Council |
| Where: | Sheraton Four Points, Conference Center |
Ancient Landscapes of the American Southwest
Wayne Ranney
March 2, 2010
Books will be available for sale
ABSTRACT:
The Colorado Plateau exposes vast layers of sedimentary strata, which contain a detailed record of the many ancient landscapes that once existed here. Seemingly ordinary layers of sandstone, limestone, and shale tell the history and climate of these past environments. These landscapes were previously “visible” only to professional geologists but with the advent of new technologies, state of the art paleogeographic maps reveal lifelike portrayals of these landscapes. These depictions describe the evolving distribution of the landscape and climate through time.
Paleogeographic maps are made when geologists study a discrete layer of strata and make an interpretation of the specific environment that produced it. Many lines of evidence are scrutinized including rock type, texture, and lateral relationships. Any environment found on planet earth today was also present in the past and making an interpretation for the environment of deposition is a relatively straightforward process. But when geologists perform multiple studies of the same layer through hundreds of miles of exposure, a large-scale geography of a past landscape can be reconstructed. Ancient Landscapes of the Colorado Plateau synthesizes voluminous amounts of previously disconnected data, allowing for these landscape reconstructions.
The process in creating the maps begins with images from space of modern features such as mountain ranges, deltas, or eolian dunes. Synthesized data permits these images to be placed in their ancient positions, over the faint outlines of modern reference points such as state, county or international boundaries. In this way, viewers are aided in locating an ancient geography relative to known political boundaries. Since a different map is constructed for each of the 70 or so named strata on the Colorado Plateau, viewing the maps sequentially appears to evolve the landscape through time. Viewers deduce how the landscape changed through time, creating a sense of discovery and awe that satisfies an intellectual and artistic curiosity. In our experience, no one is unaffected after viewing these maps! Ron Blakey has been producing the maps for almost 20 years and his maps are well known and used widely in a variety of professional and popular publications.
n>