Hunting Great Basin Elephants with Serial Transect Mapping
Chamberlain, Alan
Cordillera Resources, Inc, Eureka, NV
Serial transect mapping is an exploration method that involves
deliberately populating predetermined transect lines with geologic
constraints. This method is proving to be more efficient and cost
effective than seismic
or any other exploration method in the
essentially uncharted Great Basin of western Utah and eastern
Nevada.
Transects are planned to take advantage of well control, optimal
exposures of Paleozoic rocks, the structural grain, and any other
surface features and conditions. An experienced stratigrapher
navigates along the transect lines and collects geologic data from rock
exposures including structural, stratigraphic, biostratigraphic, and
other geological data using a survey-grade GPS.
Upon completion of the fieldwork, structural models are
constructed along the transect lines. These models are constrained
with the newly collected geologic and well data, knowledge of
structural style, and gravity, magnetic and any seismic
data and
models. Structural interpretation using structural
modeling
software
in conjunction with these geological data and geophysical data and
models where previous exploration methods have failed has revealed
sizable structures that could contain significant quantities of
hydrocarbons in this part of the Sevier Thrust Belt.
In this region, the quality of seismic
imaging is generally poor in
the pre-Tertiary strata, and consequently
seismic
interpretation is
plagued with serious limitations. As an alternative to reflection
seismic
data, serial transect mapping is about one tenth of the cost of
acquiring conventional
seismic
data, yet it provides superior
constraints on structural models over the sparsely mapped ranges of
the Great Basin.
AAPG Search and Discovery Article #90071 © 2007 AAPG Rocky Mountain Meeting, Snowbird, Utah