A Primary Observation on Palynofacies of the Chuangde Section (Late Jurassic-Cretaceous), Gyangzê, Southern Tibet

A primary study on palynofacies, which concerns the paleoenvironments from the sight of association of sedimentary organic matter preserved in sedimentary rocks, is conducted for a Late Jurassic-Cretaceous succession at Gyangzê, southern Tibet. Two palynofacies are recognized, which are formed in different sedimentary environments. The one in the pelagic is infertile in organic productivity and monotonous in component and is dominated by AOMA, while the other, being closely bound up with the slope, is characterized by abundant black phytoclasts that are possibly of algal origin and contains much AOM. The influence of terrestrial input is clear in the latter, for particles generated from terrestrial plants are common. A number of fossil spores and pollen together with some dinocysts are discovered, but they are normally in a bad condition of preservation. Nevertheless, this convinces us that the late Jurassic-Cretaceous succession in the Gyangzê area has a potential for palynological stratigraphy. We have also proved that the volume of PM can achieve similar results in presenting the productivity of organic matter as the weight of TOC does. This technique is much easier in the laboratory than that we do with TOC.

A Primary Observation on Palynofacies of the Chuangde Section (Late Jurassic‐Cretaceous), Gyangzê, Southern Tibet

A primary study on palynofacies, which concerns the paleoenvironments from the sight of association of sedimentary organic matter preserved in sedimentary rocks, is conducted for a Late Jurassic-Cretaceous succession at Gyangze, southern Tibet. Two palynofacies are recognized, which are formed in different sedimentary environments. The one in the pelagic is infertile in organic productivity and monotonous in component and is dominated by AOMA, while the other, being closely bound up with the slope, is characterized by abundant black phytoclasts that are possibly of algal origin and contains much AOM. The influence of terrestrial input is clear in the latter, for particles generated from terrestrial plants are common. A number of fossil spores and pollen together with some dinocysts are discovered, but they are normally in a bad condition of preservation. Nevertheless, this convinces us that the late Jurassic-Cretaceous succession in the Gyangze area has a potential for palynological stratigraphy. We have also proved that the volume of PM can achieve similar results in presenting the productivity of organic matter as the weight of TOC does. This technique is much easier in the laboratory than that we do with TOC.