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The Pin Formation of the northern Indian Himalaya may contain a record of the late Katian (Late Ordovician) warming event (the Boda Event). Palynological samples collected from two members of this formation are investigated in order to evaluate the biostratigraphical potential of the different microfossil groups. Acritarchs and chitinozoans are the most abundant microfossils, but fragments of scolecodonts and melanosclerites are also present. Several of the acritarchs from the Pin Formation are long-ranging through the lower Palaeozoic, but other taxa can be compared to Upper Ordovician (Katian) assemblages described from other parts of the world. The chitinozoan assemblages, consisting of 13 species (including those in open nomenclature) belonging to seven genera, are mainly recorded from two layers. The chitinozoan assemblage collected from the sample at 87.3 m in the uppermost part of the Farka Muth Member, and that collected at 184.89 m from the Takche Member, indicate a late Katian age. This age interpretation is in accordance with conodont data from the Takche Member, a positive carbon isotopic peak from the top of a shale unit in the Takche Member, and the initial part of the rapid negative shift of the Paroveja isotopic excursion related to the Boda Event of late Katian age. Further detailed studies with a higher number of samples are needed, that describe better preserved and more diversified palynomorph assemblages, which would help to more precisely refine the Upper Ordovician biostratigraphy in this area. [ABSTRACT FROM AUTHOR]

Twenty-nine core and seven cuttings samples were collected from two boreholes penetrating the Middle Ordovician Hawaz Formation in the Murzuq Basin, south-west Libya. The samples were palynologically analysed in order to determine age and depositional environment. The palynological assemblages contain abundant sphaeromorphs, rare but diverse acritarchs, rare chitinozoans, and relatively abundant cryptospores. A total of 26 acritarch species, five chitinozoan species and 17 cryptospore species have been identified. The acritarch and chitinozoan assemblages provide biostratigraphical age dating and indicate that the Hawaz Formation is Mid Ordovician and most likely mid Darriwilian (Llanvirn) in age. The cryptospore assemblage is typical of those from the Mid Ordovician–earliest Silurian and does not permit further age refinement. Based on palynofacies analysis, the depositional environment of the Hawaz Formation is interpreted as shallowing upward from nearshore marine inner shelf to marginal marine. The cryptospores provide rare evidence for Middle Ordovician terrestrial vegetation at this very early stage in its development. [ABSTRACT FROM PUBLISHER]