Different scales of salt-sediment interaction around passive diapirs

Passive diapirism entails ongoing, near-surface syndepositional growth of a salt stock or wall. As such, the diapirs and intervening minibasins influence the development and geometries of associated sedimentary strata. In this short overview, we distinguish between two scales and aspects of salt-sediment interaction that reflect a depositional continuum from the topographic highs of diapir roofs to the lows of depocenters. At the larger, multi-km scale, minibasin tectonostratigraphic successions form bowls, troughs, wedges, or layers that respond to differential evacuation of the deep salt layer. These successions have internal concordant, onlapping, or truncated geometries, and they stack into different patterns based on the evolution of active salt tectonic processes. At the smaller scale, passive diapirs create local sea-floor scarps due to drape folding of the diapir roof over the edge of the rising diapir. Depending primarily on the thickness of the roof, this results in tabular or tapered composite halokinetic sequences within 1 km or less of the diapir edge. It is important to keep these geometries and processes separate as they have distinct implications for sediment transport and deposition as well as the definition and detailed geometries of hydrocarbon traps in three-way truncations against diapirs and welds.