WHITING, B. M.¹, C. L. HANKS², W. K. WALLACE², R. LILLIE³, and J. WILLIAMS^3
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