WHITING, B. M.1, C. L. HANKS2, W. K. WALLACE2, R. LILLIE3, and J. WILLIAMS3
1Central Washington University,
Ellensburg, WA
2Geophysical Institute and
Department of Geology and Geophysics, University of Alaska Fairbanks, Fairbanks,
AK
3Department of Geosciences, Oregon State
University, Corvallis, OR.
Abstract: Evaluating alternative
models for crustal scale evolution of the central Brooks Range, Colville
Basin, and North Slope of Alaska: Insights from basin modeling
The Colville basin and North Slope of
Alaska preserve a stratigraphic record of complicated interaction among
the formation of a collisional orogen, the development of an adjacent foreland
basin, and the evolution of a nearby passive margin. Understanding the
interplay among these elements can provide new insights into tectonic controls
on the stratigraphy of many hydrocarbon producing regions. In this context,
basin modeling
is needed to: 1) constrain the shape, size, position, and
density of the Brooks Range tectonic load through time; 2) quantify large-scale
tectonic controls on sequence architecture, hydrocarbon migration, and
trap formation; and 3) estimate thermal history of source rocks. Inverse
modeling
, based on backstripping of well and
seismic
data, uses the size
and shape of the foreland basin to constrain thrust-belt properties and
lithospheric response to tectonic load emplacement and unroofing. Forward
modeling
exploits available information about the nature of the tectonic
load and eustatic signal to develop predictive models of basin architecture.
In this paper, we present basin modeling
results
for a series of time steps through the evolution of the Brooks Range and
contemporaneous basins.
Modeling
is constrained by publicly available well,
outcrop, and
seismic
data, as well as by published fission-track data.
The starting point for basin-
modeling
input is a set of crustal-scale,
area-balanced kinematic models (constrained by gravity
modeling
); each
of these represents different alternative initial configurations for the
northern Alaska Paleozoic passive margin. The implications of each alternative
model are explored through inverse
modeling
, which addresses burial depth
and basin curvature, and through forward
modeling
, which evaluates tectonic
and eustatic controls on depositional systems and stratigraphy. Results
illustrate how different sets of tectonic boundary conditions can have
profound impacts on basin stratigraphy.
AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas