SOFT SEDIMENT DEFORMATION AND INJECTITES OF THE JURASSIC CARMEL FORMATION, SOUTHERN UTAH: SEDIMENTARY RECORDS OF STRONG GROUND MOTION
The pipes have a complex diagenetic history showing preferential fluid flow via the vertical fluid conduits, particularly where the grain size is coarser around the perimeter. Bleaching rinds record the movement of reducing fluids, where there is common carbonate cement, localized iron oxide cement, and some large sparry calcite crystals.
These clastic pipes form under a unique set of circumstances including a high water table, which saturates a body of loose unconsolidated sand beneath a lower permeability layer. The dense field of pipes with broad vertical and lateral extent suggests large Jurassic earthquakes that affected the liquefaction-susceptible sabkha sediments. Repacking of the grains increases the pressure within the system and liquefies the sand causing it to scour upwards into pipes. The liquefaction likely occurred in one major event sourced from local fluvial sandstones within the Crystal Creek Member. Although seismites have been commonly recognized in the stratigraphic record, these pipes are closely tied to the complex interplay between sabkha and fluvial depositional environments along with a high water table, with pipe alignment approximately parallel to the paleoshoreline.