IRON ENRICHMENT IN BASALTIC ROCKS OF THE NEWARK BASIN: CRYSTALLIZATION IN AN OPEN SYSTEM

Recent models for the evolution of internal geochemical layers within the Mesozoic Palisades Sheet of New York and New Jersey emphasize the roles of in situ compaction and transport processes. However, presently evolving throughput models emphasize key correlations of the suggested magma pulses of the Palisades with members of the Watchung flood basalt series. Iron-enriched CAMP magma of the third Watchung flow is presently linked with a late Palisades pulse that is associated with along-strike thickening of the iron enriched horizons in the northern section of the Palisades. This is consistent with structural elements suggesting either a) the internal migration and concentration of additional magma late in the evolution of the Palisades or b) the impaction of a late pulse at the northern extreme of sill. The throughput model proposes that a subset of the internal facies of the Palisades represent resident members of one or more through-going pulses. This supports previous arguments for a zoned sub-Palisades chamber that vents into the Palisades-Gettysburg system accounting for the bulk of the mineralogical and geochemical heterogeneity observed in the CAMP magmas in the Newark Basin. We presently emphasize new correlations between the northern Palisades at Upper Nyack with the Hook Mountain Basalt that further establish a common source for horizons near the base of the Palisades and portions of the first two Watchung flows.