Table 1.

Salt Terms and Definitions

TermDefinition
Allochthonous saltA sheetlike salt body remobilized upward and emplaced within stratigraphically younger strata.
Autochthonous saltA salt layer, surface (weld), or body resting in the original stratigraphic position.
Expulsion rolloverA tectono-stratigraphic feature that forms over a flat layer of salt. This feature forms by a succession of basinward-shifting depocenters that follow basinward-spreading salt, giving the overall feature a progradational geometry.
RohoA salt system that soles onto a shallow salt nappe and has updip-extensional and downdip-contractional structures. A roho system is characterized by large, listric, basinward-dipping growth faults that sole onto a horizontal, flat salt weld and are balanced by reverse faulting in the downdip area (Schuster, 1995).
Salt bodyGeneral term referring to any individual salt feature. A salt body can be autochthonous (e.g., salt roller) or allochthonous (e.g., salt stock). An autochthonous salt body is composed of a salt stem and salt bulb. A salt body can be partially or completely welded out.
Salt canopyA composite salt structure formed by partial or complete coalescence of salt bodies or salt sheets.
Salt diapirA mass of salt that has flowed ductilely and appears to have discordantly pierced or intruded the overburden. Alternative definition: A relatively mobile mass of salt that intrudes into preexisting rocks. Salt diapirs commonly intrude vertically through denser rocks because of buoyancy forces associated with the relatively low-density salt.
Salt pillowA subcircular upwelling of salt that has a concordant overburden (Trusheim, 1960).
Salt rollerA low-amplitude, asymmetric salt structure composed of two flanks: a gently dipping flank with a conformable stratigraphic contact with the overburden and a steeply dipping flank with a normal-faulted contact with the overburden (Bally, 1981).
Salt sheetA subhorizontal salt body that originally forms, by salt expansion at or near the sea floor, from a salt-diapir configuration.
Salt stem (or feeder)The narrow part of the salt body connecting the source salt to the allochthonous salt body.
Salt stockA mushroom/bubble–shaped salt body that can have various shapes but has a deep feeder underneath connected to the mother salt (autochthonous salt) and a larger salt volume upward.
Salt sutureLimit of precursor salt bodies within the canopy is called suture.
Salt systemDefined by Jackson et al. (1994) as a system comprising a source salt layer and its overburden and subsalt strata. In the present study, an “allochthonous salt system” is defined as a group of structures that comprises (1) an allochthonous salt body (or genetically linked allochthonous salt bodies), (2) a source salt (autochthonous or deeper allochthonous salt layer), (3) salt-related stratigraphic forms, and (4) genetically related faults and folds.
Salt tongueAn unconformable salt body that intrudes obliquely into the overburden at the basinward limit of the salt layer. This term often refers to salt that is overthrusting the distal sediments at the basinward limit of the salt tectonic system.
Salt wallAn elongate upwelling of diapiric salt that forms in parallel, sinuous rows (Trusheim, 1960).
Salt weldA thin or narrow salt interval that forms when a salt layer becomes very thin resulting from salt movement, dissolution, or removal by faulting and when the overburden and the underlying subsalt strata become effectively welded together. Salt welds may also develop in the vertical direction by putting the sides of a former diapir in contact.