ABSTRACT

Gulf Coast anomalous zones in salt stocks, although highly variable, lenticular, and discontinous in detail, are commonly predictable in trend. Each zone contains several anomalous salt features, but cannot be characterized by any single feature. If anomalous features are found, look for others as they commonly occur in groups. But anomalous features can occur singly or in pairs, and these are not anomalous zones.

An anomalous zone may be of any origin, including "primary" (sedimentary), an external "sheath" around the salt stock, a "boundry" separating two spines of salt, or caused by toroidal flow within the salt. The anomalous zones observed in the Gulf Coast Stocks are vertical, linear, and concordant; most are reasonably straight, but some bend sharply, end abruptly, or coalesce.

Typical anomalous features involve:

Texture--Coarse-grain, piokiloblastic, friable

Inclusions--Sediments, hydrocarbons, brine, gases

Structure--Sheared salt, gas outbursts, brine leaks, undue slabbing, jointing, voids, a very slight porosity

Composition--Potash/magnesium, high anhydrite content, very black salt (disseminated impurities).