Ordovician conodonts from the Bulltinden Formation, Motalafjella, central-western Spitsbergen

Seven samples from the Limestone and Boulder Conglomerate Members of the Bulltinden Formation have yielded poorly preserved conodonts. On tentative identifications Periodon aculeatus Hadding and Prioniodus cf. P. alobatus Bergstrom at the base of the formation suggest an Ordovician lower Caradoc, or older age. This confirms that the Vcstgotabrcen Formation unconformably beneath underwent high-pressure mctamorphism during the Taconic and/or Finmarkian phases of the Caledonian orogeny. The conodonts show affinity to the North Atlantic Province suggesting a deeper water marine depositional environment. Conodont colour alteration indices of five indicate that the Bulltinden Formation was heated to temperatures in excess of 300°C, probably during the middle-upper Silurian main Caledonian uplift event.