Palynological processing of organic-rich rocks, or: How many times have you called a palyniferous sample 'barren'?

Campanian-Maastrichtian organic-rich carbonate and marl successions in Israel contain abundant unstructured, fluffy organic matter. Samples from these sections, which were processed by standard palynological techniques, were found to be almost completely devoid of any structured palynomorphs. On the other hand, 8-12 hours of controlled bleaching by sodium hypochlorite (household bleach) yielded extremely rich and diverse palynological assemblages dominated by dinoflagellate cysts with rare terrestrial palynomorphs. It is suggested that by selectively bleaching the organic matter, dinocysts that were incorporated within the intricate fluffy organic debris were released. The fact that many samples contained high abundance of well-preserved thin-walled dinocysts suggests that use of the controlled bleaching did not 'attack' the dinoflagellate cysts and did not cause a biased assemblage. Compared to other oxidizing methods such as the 'Schulze Solution', this method is much simpler, faster, safer and, thus, better for palynological study. The proposed method enables obtaining palyniferous slides from samples that would have been considered barren if standard palynological techniques were utilized.