Permian
stratigraphic data for the Western Interior USA, including isopachs and
paleocurrents, were digitized, compiled, and organized into a GIS database. The
data were gathered from numerous stratigraphic sources including analog maps and
cross sections. GIS, a developing geoscientific tool, is explored and
implemented to merge, systematize, present, and perform tedious calculations of
large stratigraphic datasets. Consolidating the information into a georeferenced,
visual format allows for the identification of regional trends in complex
stratigraphic sequences. The database permits easy updating and correction of
information by an individual user.
The Permian
was divided into four sequences based on previous work: 1) Cedar Mesa-Esplanade,
2) Schnebly Hill-DeChelly-Coconino, 3) Toroweap, and 4) Kaibab. These rocks
comprise a diverse suite of shallow marine, eolian, sabkha, fluvial, and coastal
plain deposits that formed in several basins adjacent to and distal from the
greater Ancestral Rocky Mountains. The presentation format readily allows the
rocks of these sequences to be visually presented as a series of rectified
graphics that can be analyzed independently or compared and contrasted with each
other. Visuals include Permian isopach, paleotectonic, paleoenvironment, and
paleogeographic maps that contain hyperlinks to stratigraphic columns and
outcrop photographs. Metadata files accompany each shapefile and specify the
data source, original data format, map datum, data manipulations, date of
construction, and designer.
The
completed project will create a single database that combines, organizes, and
displays the collections of Permian data for the Western Interior. The project
is mirrored in a website so as not to be software dependent. The website,
http://jan.ucc.nau.edu/~rcb7, contains a downloadable copy of the GIS database
and web pages with the final products. This presentation method is significant
because it orchestrates varying, complex, and independent information from a
variety of sources, formats, and presentation styles that can be readily
manipulated by the individual user.
ZAHLER, Michael A., &
BLAKEY, Ronald C., Geology, Northern Arizona University,
Box 4099, Flagstaff, AZ 86011,
michael.a.zahler@gmail.com
Introduction
The following maps give the viewer, laymen
through professional, an interpretation of the stratigraphic record from 299-251
Ma with current bed thickness overlain. The five final maps produced are
available in a web browser so as not to constrain the curious by
hardware/software needs. The stratigraphy for the Western Interior is
complicated by 299 million years of changing tectonic controls. The continued
uplift of this region from the sea and coastal elevations and migration of the
North American plate clockwise and north of the equator has driven many
depositional environment changes and structural controls. These factors, and
many others, have resulted in differential weathering and preservation of the
original Permian deposits.
Created by Zahler, M.A. Dated 10/06
Zahler, M.A., 2006 Senior Thesis