A middle Ordovician faunule from the Tetagouche Group, Camel Back Mountain, New Brunswick
DOI | 10.1139/e79-049 |
---|---|
Aasta | 1979 |
Ajakiri | Canadian Journal of Earth Sciences |
Köide | 16 |
Leheküljed | 540-551 |
Tüüp | artikkel ajakirjas |
Keel | inglise |
Id | 50435 |
Abstrakt
The Tetagouche Group is a 10 000 m geosynclinal sequence of slates, greywackes, rhyolite tuffs, and greenstones underlying parts of northern New Brunswick. It hosts the well-known stratabound massive sulphide deposits of the Bathurst–Newcastle mining area. Few fossils have been found in the group and its age is poorly known. More than 890 conodonts have been recovered from a locality near Camel Back Mountain in the Metabasalt unit. Coelocerodontus? lacrimosus and Protopanderodus liripipus are described as new species. The faunule contains species indicative of the Prioniodis alobatus Subzone of the Amorphognathus tvaerensis Zone and is the first record of the subzone in North America. The subzone equates with the middle Caradocian (approximately the Soudleyan Stage) or late Wildernessian Stage of the Middle Ordovician Epoch. During this interval the Proto-Atlantic Ocean is considered to have been undergoing closure, hence recent interpretations that regard the Metabasalt unit as forming during an earlier phase of opening must be reexamined.