Investigation of Thermal Maturity of  Organic Matter at the Cambro Ordovician Transition in the Zagros Basin, Iran

Sammanfattning: The thermal maturity of sediments from the upper Cambrian to lower Ordovician Mila and Ilbeyk  formations in the Zagros Basin in southwestern Iran is evaluated in this thesis. A number of low-cost,  fast, optical evaluation methods are utilised to assess their effectiveness for providing accurate, well  constrained thermal maturity results. Palynomorph colours under transmitted light are measured using  two optical evaluation methods (Palynomorph Darkness Index , PDI- Goodhue & Clayton 2010;  Acritarch Alteration Index, AAI- Legall et al., 1981) to study 540 acritarchs of three acritarch  morphotype-groups: acanthomorphs, Cristallinium-type and veryhachides. Correlation of the PDI and  AAI results collected in this study with UV fluorescence and rock-eval pyrolysis data taken from  previous studies suggests that the studied sediments are within the wet gas thermal maturity window.  Furthermore, investigating the PDI results of acritarchs allowed for the identification of reworked or  recycled acritarchs. Investigation of the stratigraphy of strata containing abundant reworked or recycled  acritarchs allowed for the identification of a ravinement surface in a transgressive shallow water  depositional environment in the studied strata.