Early Silurian conodonts from the Quinton Formation of the Broken River region (North-Eastern Australia)

The Early Silurian Quinton Formation in the Broken River region of north Queensland is a thick, largely turbiditic sequence with several small allochthonous carbonates. These limestones yield an Early Silurian conodont fauna of late Llandovery celloni Zone to late Llandovery/early Wenlock amorphognathoides Zone. To the south the lateral equivalent of the Quinton Formation (previously referred to as the Poley Cow Formation), is thinner and less turbiditic; it includes one isolated, presumably allochthonous, carbonate at the Broken River Crossing which has also yielded Early Silurian conodonts of similar age. These allochthonous units therefore align chronologically, indicating probable derivation from the same general source. The lack of any major chronological disparity between conodonts from the allochthonous limestonesand late Llandovery graptolites of the enclosing clastics indicates the penecontemporaneous nature of erosion and redeposition of these carbonates.