Abstract
New major– and trace– element analyses of the Messozoic basalts of the Hartford Basin of Connecticut (the Talcott, Holyoke, and Hampden Basalts) indicate that the basalts are chemically very similar to the Mesozoic basalts of the Newark Basin of New Jersey (the First, Second, and Third Watchung Basalts). Our geochemical data impose some constraints on any time-stratigraphic correlation of the basalts in the two basins. We suggest that the Holyoke and Second Watchung Basalts are fractionation products of a Talcott-First Watchung parent magma. We also suggest that the Hampden and Third Watchung Basalts are synchronous fractionation products of a magma unlike any of the eastern North American basalt types described in the literature, but they may instead be the fractionation products of a magma resembling a magma of the same type as that of the Mid-Atlantic Ridge. From a petrologic standpoint, the most straight-forward time-stratigraphic interpretation is a one-to-one correlation of the three flows of the Newark Basin with the three flows of the Hartford Basin. Our geochemical and petrologic evidence is particularly supportive of time-stratigraphic correlations between the First Watchung and the Talcott basalts and between the Third Watchung and the Hampden basalts. Our data, however, are not inconsistent with the possibility that the Second Watchung may be slightly older than the Holyoke Basalt.