About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
AAPG Bulletin
Abstract
AAPG Bulletin, V.
DOI:10.1306/04240605144
Hyperpycnal flow variability and slope organization on an Eocene shelf margin, Central Basin, Spitsbergen
Andrew L. Petter,1 Ronald J. Steel2
1Department of Geological Sciences, University of Texas at Austin, 1 University Station, C-1100, Austin, Texas 78712; [email protected]
2Department of Geological Sciences, University of Texas at Austin, 1 University Station, C-1100, Austin, Texas, 78712
ABSTRACT
Identification of bypass at the shelf margin is critical to deep-water exploration. We examine the shelf margin of an early Eocene fourth-order sequence with an attached basin-floor fan in the Spitsbergen Central Basin. Turbidity currents were fed mainly by hyperpycnal flow emerging from shelf-edge deltas. The life span of any turbidity current was determined primarily by the sediment concentration of the flow and the duration of the river flood. High-density hyperpycnal flows created sand-filled slope-channel complexes 10–15 m (33–49 ft) thick and 100–200 m (328–656 ft) wide that served as conduits for bypass to the basin floor. Low-density hyperpycnal flows were unconfined and deposited heterolithic lobes on the slope. Shelf-margin accretion of about 1.5 km (0.9 mi) during the falling stage gave way abruptly to bypass in the early lowstand. Most of the basin-floor fan growth was achieved after shelf-edge incision and before relative sea level rise. Coastal-plain aggradation in the late lowstand sequestered sediment from the shelf-edge distributaries, effectively diminishing high-density hyperpycnal flow output. The late lowstand was therefore marked by a second phase of shelf-margin accretion with only limited bypass to the basin floor, and a heterolithic, prograding complex downlapped the early lowstand channels. Transgression ultimately led to the abandonment of the shelf-edge delta complex and the accumulation of mainly mudstone on the margin. The shelf-margin architecture exhibited by this sequence should serve as a type example of a deep-water feeder system in which hyperpycnal flow is the primary initiator of turbidity currents for sand accumulation on the slope and basin floor.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |
AAPG Member?
Please login with your Member username and password.
Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].