Brookian maturation and erosion framework of North Alaska
- Arco Alaska, Inc., Anchorage, AK (United States)
- Arco EPT, Plano, TX (United States)
Quantifying the timing and magnitude of syn- and post-orogenic loading and unroofing within fold and thrust deformation belts and adjacent foreland basins is critical for evaluating reservoir quality, the timing and degree of source rock maturation, and the timing of trap development. The present-day sub-surface thermal structure and the timing and amount of eroded section during the Brookian Orogeny in North Alaska have been quantified by integrating DST and log temperature, apatite fission track, vitrinite reflectance, and sonic velocity data. Constraining the present-day thermal structure is particularly important for interpretation of thermal indicator data in this area, because thermal gradients systematically vary within the range 25-55 {degree}C/km with the highest gradients present along the crest of the Barrow Arch. Erosion estimates range from 0-0.6 km in the Prudhoe Bay/East Beaufort Sea area, and increase to the west and south, reaching {approximately}1.8 km in the Point Barrow area, and >3.7 km along the Brooks Range mountain front. The spatial and temporal distribution of erosion reflects contributions form short-term compressional and long-term isostatic processes. Significant erosion (>2-3 km) during short periods (<5 Ma) is localized along thrust sheets in-board of the deformational fonts and was responsible for synchronous deposition of clastic wedges outboard of the deformational fronts. Surface fission track data delineate the culmination of several discrete Brookian thrust belts (ca. 60, 45, 20 Ma), the latter two of which are localized in the NE Brooks Range. Protracted post-orogenic erosion west of the Shaviovik Fron since 60 Ma is due to flexural tilting of the foreland and represents an isostatic response to unroofing of the orogen.
- OSTI ID:
- 425509
- Report Number(s):
- CONF-960527-; TRN: 96:004994-0142
- Resource Relation:
- Conference: Annual convention of the American Association of Petroleum Geologists, Inc. and the Society for Sedimentary Geology: global exploration and geotechnology, San Diego, CA (United States), 19-22 May 1996; Other Information: PBD: 1996; Related Information: Is Part Of 1996 AAPG annual convention. Volume 5; PB: 231 p.
- Country of Publication:
- United States
- Language:
- English
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