ABSTRACT

The Harang and Hackberry are seaward thickening argilliaceous facies in the younger Tertiary of South Louisiana and adjacent areas. The Harang facies is identified by the presence of the Harang foraminiferal fauna and is found near the middle of the South Louisiana Miocene of the eastern coastal parishes. The older Hackberry facies contains the Hackberry foraminiferal assemblage and is found in the Frio formation, which extends across coastal Louisiana and Texas. The Hackberry is best developed, in Louisiana, in the southwestern part of the state.

Study subsequent to previous publication on the Harang facies indicates: (1) the lower limit of the facies in fringe areas is the approximate top of the Amphistegina zone rather than the Discorbis zone; (2) the approximate updip limit of the facies trends southeast from New Orleans, generally excluding areas east of the Mississippi river; (3) an area of typical development exists in central Lafourche Parish; and (4) Planulina harangensis Cushman and Ellisor is not necessarily the best marker for this facies.

Good possibilities for production of hydrocarbons exist both above and below these facies, although production from within the Harang and the Hackberry in their areas of typical development is negligible.