31. CHLOROPHYLL DERIVATIVES IN DSDP LEG 31 SEDIMENTS

A continuous history of the chemical degradation of chlorophyll to petroporphyrin in marine environments is recorded in deep ocean sediments. An understanding of the reactions and mechanisms of the early phases of chlorophyll diagenesis was the goal of the investigation of a suite of Leg 15 Pleistocene cores (Baker and Smith, 1973). Next, attempts were made to unravel and extend the diagenetic scheme into the Tertiary and Upper Cretaceous through a study of Leg 22 and Leg 29 sediment cores (Smith and Baker, 1974; Baker and Smith, in press). However, samples from these legs were very low in tetrapyrrole pigment concentration, and consequently pigment characterization depended entirely upon electronic absorption spectroscopy and chromatographic properties of the compounds. Due to extremely limited pigment availability, application of mass spectroscopy was not possible. In the present study, 11 sediment samples spanning a geologic age from early Pleistocene to Miocene were selected from Leg 31 cores (Table 1), and analyzed for tetrapyrrole content. The results reported herein represent a preliminary investigation of those samples which afforded pigment in sufficient quantity for mass spectral analysis.