Palynofacies studies examine the preservation of particulate organic matter and palynomorphs to provide information on the depositional environment of sediments and depositional palaeoenvironments of sedimentary rocks. The term Palynofacies was introduced by the French geologist Combaz in 1964. Palynofacies studies are often linked to investigations of the palynology and organic geochemistry of sedimentary rocks.
Palynofacies can be used in two ways:
- Organic palynofacies considers all the acid insoluble particulate organic matter (POM), including kerogen and palynomorphs in sediments and palynological preparations of sedimentary rocks. The sieved or unsieved preparations may be examined using strew mounts on microscope slides that may be examined using a transmitted light biological microscope or ultraviolet (UV) fluorescence microscope. The abundance, composition and preservation of the various components, together with the thermal alteration of the organic matter is considered.
- Palynomorph palynofacies considers the abundance, composition and diversity of palynomorphs in a sieved palynological preparation of sediments or palynological preparation of sedimentary rocks. The ratio of marine fossil phytoplankton (acritarchs and dinoflagellate cysts), together with chitinozoans, to terrestrial palymomorphs (pollen and spores) can be used to derive a terrestrial input index in marine sediments.
Both types of palynofacies studies are used for geological interpretation of sedimentary basins in exploration geology, often in conjunction with palynological analysis and vitrinite reflectance.