The palaeobiogeographic significance of lower carboniferous crustaceans (ostracodes and peracarids) from western Newfoundland and central Nova Scotia, Canada

Abstract

Lower Carboniferous sediments of the Maritime Basin of eastern Canada were deposited in a predominantly fluvial environment subjected to transgressive marine episodes. A dominantly shallow marine peracarid and ostracode fauna, the latter consisting mostly of paraparchitaceans, palaeocopids and bairdiaceans, has been recovered from sediments in the area. The Maritime Basin is considered to have been a tectonically active epicontinental extension of the northern Hercynian Ocean. Its lower Carboniferous crustacean fauna shows a strong affinity to contemporaneous western European and Russian faunas. The high degree of similarity exhibited by these faunas, and also the lack of similarity to contemporaneous North American and North African faunas, are explained in terms of a circulation model for the Hercynian Ocean and adjacent areas. The circulation model is based upon the application of the physical principles that define the behaviour of oceanic surface waters, to a palaeogeographic reconstruction of the Visean northern Hercynian Ocean and surrounding regions.