Reflectance and composition of dispersed organic matter at DSDP Leg 67 Hole

Dispersed organic matter of plant origin from three sites of the Middle America Trench transect was investigated by coal petrographic methods. Samples from the slope region are rich in lipoid and inert substances. Humic matter is predominant in the trench sediments. Reflectance measurements show that the rank of the organic matter is peat, independent of the tectonic position and age of the samples in question. A slow increase of coalification with depth is observed.