About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

AAPG Bulletin, V. 107, No. 1 (January 2023), P. 7-22.

Copyright ©2023. The American Association of Petroleum Geologists. All rights reserved.

DOI: 10.1306/0104202221069

Different scales of salt–sediment interaction during passive diapirism

Mark G. Rowan1 and Katherine A. Giles2

1Rowan Consulting, Inc., Boulder, Colorado; [email protected]
2Institute of Tectonic Studies, Department of Earth, Environmental, and Resource Sciences, The University of Texas at El Paso, El Paso, Texas; [email protected]

ABSTRACT

Salt–sediment interaction during passive diapirism typically occurs at two distinct scales that are related to depositional relief from the highs above diapirs to the lows of adjacent depocenters. At the large scale, subsidence into salt generates horizontal to gently dipping depositional surfaces and consequent minibasin tectonostratigraphic successions. These have widths of multiple kilometers and geometries categorized as (1) layer minibasin tectonostratigraphic successions, with strata maintaining their thickness approaching the diapir; (2) thinning-wedge minibasin tectonostratigraphic successions, in which the bounding surfaces converge toward the diapir; and (3) thickening-wedge minibasin tectonostratigraphic successions, where they expand toward the diapir. Internally, wedge minibasin tectonostratigraphic successions comprise smaller-scale stratal wedges that are concordant, discordant, base-discordant, or top-discordant. Minibasin fill may form a single minibasin tectonostratigraphic succession or have one or more switches between different minibasin tectonostratigraphic succession types. At the small scale, drape folding of the roof over the steep diapir edge generates a topographic scarp and resultant diapir-flanking, unconformity-bound halokinetic sequences that are less than 1 km wide. Halokinetic sequences stack into composite halokinetic sequences: hook halokinetic sequences form when the roof is thin and stack into tabular composite halokinetic sequence within 200 m of the diapir; and wedge halokinetic sequences represent thicker roofs and stack into broader, Previous HittaperedTop composite halokinetic sequences. Distinguishing between the two scales of salt–sediment interaction is important because they have different implications for exploration and production in three-way traps against diapirs or equivalent welds. Different stacking patterns of minibasin tectonostratigraphic successions impact risk assessment of trap size, reservoir thickness trends, and hydrocarbon charge, whereas composite halokinetic sequences complicate the updip portions of traps and impact both reservoir distribution and seal.

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].