HAWKINS, LOCEATONG FORMATION OF THE TRIAS SIC 14^ 



L:_L 



Where continuous exposures are available near 

 Princeton, the succession of beds usually can be ob- 

 served to be about as follows : At the lowest portion 

 of the section examined (as in McCarthy's quarry, 

 Princeton) there is a thick series of strata of dense, 

 reddish brown, flaggy argillite. At its upper limit 

 the brown bed suddenly loses its characteristic color, 

 and passes, without change in other respects, into a 

 dark gray rock, the most tj^pical argillite of the series. 

 A short distance higher up in the dense gray rock, 

 radiating crystal growths occupy a horizon about a 

 foot thick, with irregularly scattered white crystal 

 specks in the la3'er immediately above, as hereafter 

 described. Above this horizon there is apt to be an 

 inch or so of very black, carbonaceous shale, followed 

 by one or two inches of a light gra}^, thoroughly crys- 

 talline magnesian limestone. This is again succeeded 

 bv an inch of black shale, above which there are gray 

 argillite beds. Still higher more red rocks may ap- 

 pear, and the whole series, as above described, may be 

 repeated. 



CoLUMXAR Sections 



Columnar sections of the Lockatong series are 

 shown in Fig. 1. The » sections are numbered from 

 1 to T, beginning at the west. They are arranged im 

 order of occurrence, being spaced at approximately 

 correct relative distances horizontally. The vertical, 

 scale is made, for convenience, ten times the horizon- 

 tal. The datum plane selected for correlation of the- 

 various sections is the top of the massive argillites',.. 

 whose deposition marked the time of steadiest sedi-- 

 mentation and most sluggish drainage, which in turn: 

 signifies a nearly level surface throughout the area.. 

 It is to be noted that this arrangement brings the; 

 prominent Estheria beds, near the base of the three 

 western sections, to about the same level. The transi- 

 tion beds are represented by black bands where they 

 occur, in the upper and lower part of each section, 

 and the outline of the basin has been completed to 

 show how a repeated interdigitation of the Stockton 



