The Gibsland Salt Stock Family in Northwestern Louisiana

ABSTRACT A semi-regional isopach map of the Hosston-Sligo interval in North Louisiana suggests the existence of a salt family similar to Sanneman's (1968) example in the Zechstein Basin of northwestern Germany. The mother salt stock appears to be the Gibsland Salt Dome in Bienville Parish which the isopach map indicates had a well developed rim syncline in Hosston time. Withdrawal of salt into the Gibsland dome appears to have triggered the growth of peripheral salt pillows such as Vacherie, Minden, Athens, Sugar Creek, and Arcadia. Some of these pillows subsequently developed into salt stocks. The centrifugal or outward growth of salt structures continued with the withdrawal of salt from beneath the Minden sub-basin into the Minden and Bistineau salt domes. This accentuated growth of the Sligo, Bellevue, and Cotton Valley salt pillows which in turn, triggered development of the Pine Island salt pillow in latest Early Cretaceous time. The growth of the salt structures progressed outward from deeper to shallower portions of the North Louisiana Salt Basin. An older salt family may be centered on the Winnfield or Cedar Creek salt domes in the deepest part of the salt basin. Centrifugal growth of these stocks should be discernible in seismic profiles. A knowledge of the relative ages of these structures is important in predicting sites of Lower Cretaceous reefs and hydrocarbon migration paths.