Abstract
A coorongite sample (black elastic material occurring as sheet- like deposits around lagoons or in dried-up basins) was analysed by (super 13) C NMR, GC-MS, and other techniques. The results indicate derivation of the coorongite from organic matter of the microalga. Highly specific pyrolysis products indicate that C (sub 27) ,C (sub 29) and C (sub 31) alkadienes and alkatrienes, originally present in the alga, were cross-linked by oxygen during early diagenesis under oxic conditions. Under specific conditions kerogen consists of preserved biomacromolecules and insoluble, cross-linked, low-MW lipids.