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Petroleum Geological Survey
Published in Muhammad Abdul Quddus, Petroleum Science and Technology, 2021
Palynology is the branch of bio-stratigraphy that studies small living species and their fossils. The main focus is on ‘pollens’ and ‘spores’. Pollens are fine to course powder-like materials and are produced by land plants. They occur in the seeds and flowers of a plant which produce a male gamete (sperm cell). Spores are asexual and uni-cellar organisms, for example lower organisms like algae and fungus. These spices have a microscopic structure (5–500 nm). They are chemically stable and decay very slowly. They are not only abundant in sediments and sedimentary rock but also spread in the vast area of the atmosphere and hydrosphere. Pollen and spores in the presence of oxygen in the atmosphere are not as stable as in the preserved sedimentary deposits in the absence of oxygen. Pollen and spores exhibit polymorphism. They exist in many forms. Pollen and spore fossils are important tools for the study of bio-stratigraphy and palynology of sedimentary rock. Palynology covers the recent geological period known as the ‘Quaternary period of Cenozoic era’, spanning from 2.58 million years ago to the present age.
Origins of clay-rich strata in Cenozoic paleochannel deposits: an example from Suttor Formation, Queensland
Published in Australian Journal of Earth Sciences, 2023
T. Yu, J. Cooling, J. Esterle, T. Chadwick, A. Babaahmadi
Both the sedimentary strata and the basalts are variably to deeply weathered, a process that is thought to have occurred during the mid to late Cenozoic and resulted in mottled and leached profiles (Hutton et al., 1998). As part of an in-depth study of oil shales, including those from the Suttor Formation, kaolinite is recorded as the dominant mineral in the clay-rich strata. This kaolinite is suggested to have been formed by the intense weathering and erosion of aluminium silicate minerals in the region’s highlands prior to deposition in the channels (Glikson-Simpson, 2021). However, kaolinite could also result from deep weathering of igneous intrusives associated with the basalt flows. The nature of the clay minerals, together with the palynology, can provide insight into paleoclimate and provenance of sediments, and contribute to understanding the geological history (Singer, 1984). Henderson and Nind (2014), working in the younger Pliocene Campaspe Formation in northeast Queensland, recorded a predominance of vermiculite and smectite-rich illite/smectite mixed-layer clays. They interpreted a complex origin for clay assemblages, involving erosion and deposition of weathered precursors, with subsequent modification by pedogenic processes with minor diagenesis following accumulation.