New geographic information systems (GIS) technology allows
us to rapidly combine the traditional color gravity and magnetic
maps with pseudo-sun shading and a variety of geologic and geographic
overlays. This approach can be used to readily identify and characterize
structural and stratigraphic features within the basement, and
correlate these features with structural and stratigraphic features
in the overlying strata, including the location of oil and gas
fields. Interpretation of the color and sun-shaded gravity and
magnetic maps show major Precambrian tectonic features, as well
as numerous but more subtle structures and lithologic trends associated
with these features. On these maps, the important features for
petroleum exploration and development are the boundaries between
anomalies, and alignments of anomalies. These lineaments are indicated
by steep gravity or magnetic gradients which cause increased shading
on the maps, or by the regional alignment of gravity and magnetic
gradients and the anomalies associated with them. The lineaments
appear to correlate with numerous geologic features, including
Precambrian lithologic boundaries and structures interpreted from
well control, flexures or faults that cut various levels of overlying
strata, variations in Paleozoic lithofacies and stratal geometries,
and trends of numerous oil and gas fields. These lineaments are
interpreted as simple lithologic boundaries or Precambrian structures,
some of which may have influenced deposition, structural evolution,
paths of fluid migration, and the location of oil and gas fields
in overlying strata. In light of this interpretation, the gravity
and magnetic maps could be used as a low cost way of identifying
structures and stratigraphic changes that affect oil and gas accumulations,
and thus, continue trends of existing fields and plays.