A sample of the Salt Mountain Limestone (Paleocene) from Jackson, Alabama, has yielded a diverse nannoplankton flora. Preservation differs greatly between species. Some forms are well preserved whereas others have been subjected to extensive dissolution and/or recrystallization. Placoliths generally are well preserved, but the centers of many specimens are obscured by pelatoid overgrowths. Many specimens also bear sparry extensions of isolated shield elements.

The presence of Discoaster gemmeus, and the absence of recognizable specimens of Discoaster nobilis and Heliolithus riedeli, places the Salt Mountain Limestone within the Discoaster gemmeus Zone. This suggests that the Salt Mountain Limestone is older than the Nanafalia Formation which has been placed in the Heliolithus riedeli Zone. Toulmin suggested that the Salt Mountain Limestone was an offshore facies equivalent of the Ostrea thirsae beds of the Nanafalia Formation.

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