10 INTRODUCTION 



upon presentation of a theory more nearly fitting the known facts. 

 While the pine-barrens do occupy Tertiary soils, they do not 

 occupy all of them. It is just this lack of co-extensiveness of the 

 pine-barrens in New Jersey with the Tertiary that has led to Dr. 

 Stone's scepticism. 



1 8. At the risk of burdening the present work with more of 

 technical geological matters than are usually found in a purely 

 botanical survey, the writer feels it is only by a knowledge of what 

 the geological changes have been, on the coastal plain in New Jersey, 

 that we can arrive at the facts in the distribution of the plants 

 of the region. For here, it seems, the whole make-up of the flora 

 is directly attributable to the geological processes that are de- 

 scribed in the next succeeding paragraphs. 



19. Going back to the time when all the coastal part of New 

 Jersey south of a line from Jersey City to Flemington (see map, 

 pi. 1) was under water, owing to the last great general sub- 

 mergence of the continent, we find that during this period a great 

 deal of erosion of the unsubmerged land took place. This sinking 

 of the coastal part of New Jersey, and of course elsewhere, known 

 to geologists as the Miocene sinking,* had a profound influence on 

 the configuration of the lower part of the state. All the material 

 from the north and northwest that was washed down, or eroded, 

 went out with the water and was finally deposited over this sub- 

 merged area, and this deposition went on for countless ages. Ulti- 

 mately this Beacon Hill formation, as the deposited material is 

 called, became very thick, covering practically all the lower part 

 of the state. 



20. "After the deposition of the Beacon Hill formation, the 

 area over which it had been spread was again elevated, and the 

 history of the topography of all that part of the state, which was 

 covered by the formation, . . . dates from this reemergence of 

 the surface covered by the Beacon Hill formation. "f This emer- 

 gence of the land is spoken of by geologists as the Post-Miocene 

 uplift or Pre-Pensauken cycle of erosion. Whatever the termin- 

 ology used, the result was to bring above water most of the land 

 that had been previously submerged. Not quite all of it, however, 

 for the land was not perfectly level, and only the highest portions 



* Salisbury, R. D. Final Rept. Geol. Survey of New Jersey 4: <)2. 1898. 

 f Salisbury, R. D. hoc. fit. 93. 



