150 KUMMEL AND WELLER LIMESTONES OF KITTATINNY VALLEY 



cut west of Hamburg station, a true quartzite occurs. Here a thin band 

 of slightly arkose, vitreous quartzite is shown resting upon the granite. 



Drift conceals all exposures for 10 or 12 feet, bej^ond which there are 

 calcareous sandstones and sandy limestones for 45 or 50 feet. Fifty feet 

 higher in the series a shaly limestone is exposed in an old quarry. Near 

 Allamuche an arkose conglomerate occurs at the base of the formation. 

 Pebbles 2 to 4 inches in diameter occur, although they are usually less 

 than one inch. Pebbles of slate were noted in addition to the quartz, 

 feldspar, mica, granite, and gneiss commonl}'- present. 



The quartzite is usually a blue-gray color when fresh, but some beds 

 are a light yellow-brown, and others are nearly white. The arkose con- 

 glomerate layers vary considerably, owing to the varying shades of color 

 of their constituents. 



The thickness of the formation as given by Wolf and Brooks is from 

 " 30 feet to a foot or less." In our wider studies it has frequently been 

 found to have a much greater thickness. The conglomeratic phase is 

 known to exceed 100 feet at a number of localities. In the railroad 

 cuts at Washington, New Jersey, where the quartzite can be seen to rest 

 on the slightly undulatory surface of a coarse grained pegmatitic grani- 

 toid-gneiss, it has a thickness of 100 feet, grading upward into a sandy 

 limestone, of which 15 feet are exposed, and.which is in turn succeeded 

 by at least 10 or 15 feet of sandy sliales. If these transition beds are 

 to be included in the quartzite formation, its thickness here is at least 

 140 feet. Thin beds of shale, sandstone, and impure limestone have 

 elsewhere been noted at about the same distance, 120-140 feet above the 

 base of the formation. North of Clinton, on the southeastern flank of 

 the highlands, the conglomeratic quartzite is over 185 feet thick, the 

 top not being exposed and the transition beds not being included in the 

 measurement. 



" The varying constitution, the local derivation of the material, and the 

 great range in thickness indicate that the conglomerate is a shore de- 

 posit. Its increase in thickness toward the southeast locates the Cam- 

 brian land in that direction. Its occurrence on the southeastern flank 

 of the highlands proves that the land lay farther east than the present 

 highlands and probably even east of the present limits of the state. 



r.ower Cambrian trilobites have been found by Beecher, Foerste, and 

 others in this formation near Franklin Furnace and Andover, and by 

 Weller at various points from Franklin to Washington. They can be 

 recognized onl}^ in the calcareous sandstone beds and here only in the 

 weathered portion of the rock, from which the calcareous matter has 

 been dissolved. This weathered rock is of a deep brown color, arena- 

 ceous and friable. It splits readily along the planes where the trilobite 



