Soudan Formation: Organic Extracts of Early Precambrian Rocks.

Biological-type alkanes are present in rocks of the Soudan formation that are more than 2.7 x 10(9) years old, but evidence of life in Soudan times is marginal. The distributional patterns of the alkanes from various regions in the Soudan indicate an indigenous origin of these compounds. Isotopic analyses do not confirm the compositional analyses.