Scenic Lawrence Brook -  Geology

 (click  for  a full  map)  



Maps source : New Jersey Geological  survey

The Lawrence Brook  flows SW  to  NE, mostly between the  piedmont region (light blue)  and the  inner costal  plain (light green).

Jurassic diabase appears along  the upper Lawrence Brook (pink).

The areas crossed by the Lawrence Brook are  Mesozoic (Triassic, Jurassic and Cretaceous).
Million  years  Where it appears along the Lawrence Brook
Cenozoic   today


Mesozoic Cretaceous -150 Most of the right  bank of the Lawrence Brook
Jurassic -200 Diabase boulders along upper parts of the Lawrence Brook
Triassic -250 most of the  left bank of the Lawrence Brook
Jurassic diabase boulders along  Mayes  brook. 

Diabase is  magma that had cooled underground (plutonic); it  has been partly exposed by erosion of upper layers. This is  a continuation of the Palisades.

The  brook in the  native forest (Helyar Woods), flows into  the Weston Mill Pond Triassic red shale in Helyar forest