The Palisades Sill & Watchung Mountains: A tale of Pangea Rifting in the Newark Basin

The Palisades Sill & Watchung Mountains of New Jersey and New York reflect rifting of the Pangea supercontinent from Laurentia during the Triassic Period. This booklet offers an introduction to the Palisades Sill along with its geochemical signatures which reveal the sill's plume source and geological history. Part I presents the Palisades Sill offering a discussion of the geologic history, trace element geochemistry, and discussion of the plume source for the sill's emplacement.The Watchung Mountains consists of three mountain ranges paralleling each other in northern New Jersey forming coincidental with the Palisades Sill. Geologic setting of the Watchung Basalt flows, glaciation, structure, stratigraphy of the adjacent rocks, and igneous activity are presented in Part II of this booklet. Part II discusses the Watchung Mountains and its geologic setting, glaciation, stratigraphy, and geologic age, upper Triassic eruptions in New Jersey, igneous activity and its geologic age, regional and local stratigraphic relations, nature and products of basaltic eruptions including sites of fissures, pre-eruptive character of the Newark Basin graben, surface character of the vesicular traps, and geologic processes of jointing systems. Part II finishes out with petrochemistry, megascopic characteristics of the basalt, characterization of pristine gases, history of tectonic subsidence and volcanism in the Newark Basin, structure of the Newark Basin at the close of the Triassic and post Triassic deformation, Triassic tensional history, and supplementary topics discussing bubble formation processes.