Palynological calibration of Devonian events at near-polar palaeolatitudes in the Falkland Islands, South Atlantic

Abstract

AbstractIn the Devonian, the Falkland Islands were part of the high-latitude Cape Basin. West Falkland palynological assemblages are at a low thermal maturity level but also very low in diversity and dominated by simple spores with rare chitinozoans and acritarchs. The South Harbour Member contains rare verrucate and sculptured trilete spores, and is early Lochkovian. The Fish Creek Member palynofloras are late Lochkovian. The best correlative datum is the transgressive Fox Bay Formation where the palynological assemblage includes Ramochitina magnifica and is equivalent to the Sequence B transgression in Brazil (dated as late Pragian–earliest Emsian). The early Eifelian upper Fox Bay Formation spore assemblage is comparable to the Sequence C transgression in Brazil and the ?Choteč Event. The facies and position of the base Port Philomel Formation prasinophyte-rich black shale suggests the late Eifelian transgression (Kačák Event). Above this level is the inception of Geminospora lemurata (base Givetian). The upper Port Stanley Formation contains a late (but not latest) Famennian assemblage. Comparisons with both South Africa and South America indicate a number of correlative transgressive and regressive events that match to Euramerica. These correlations are at a continental scale and confirm eustatic control of these Devonian events.