372 HENRY B. KUMMEL 
siliceous phase elements of the Hornerstown fauna occur in association 
with forms characteristic of the calcareous phase. Its thickness 
varies from 25 to 70 feet, but well-borings have shown that it thickens 
greatly down the dip’ It rests conformably upon the Hornerstown 
marl and is overlain conformably by the Manasquan marl or over- 
lapped by Miocene beds. It includes the “limesand” and “yellow 
sand” of Cook, the former of which was regarded by him as a part of 
the Middle Marl. 
Manasquan marl.—The Manasquan marl in its lower portion 
(13-17 feet) is composed chiefly of glauconite, but the upper part 
(8-12 feet) is made up of very fine sand mixed with greenish-white 
clay, piles of which look like heaps of ashes—hence the name “ash 
marl.” The fossils are not abundant and are poorly preserved, 
the commonest occurring also either in the Hornerstown or Vincen- 
town. Its thickness is about 25 feet. It corresponds to the “green” 
and ‘‘ash” marls of Cook’s Upper Marl bed and is the youngest of 
the Cretaceous formations exposed in New Jersey. It probably 
rests conformably upon the Vincentown and at most exposures is 
succeeded unconformably by Miocene or Pleistocene deposits, 
although locally it is overlain by a bluish marl of Eocene age with- 
out apparent unconformity. 
Correlation of the Hornerstown, Vincentown, and Manasquan.— 
The faunas of these three formations are closely related, and form 
a larger fauna sharply separated from the Ripleyian fauna of the 
underlying Magothy and Tinton beds. This fauna has not been 
recognized south of Maryland. It shows certain affinities with the 
lower or Maestrichtian division of the Danian series of Western 
Europe (Weller). 
EOCENE SYSTEM 
Shark River marl.—Eocene deposits in New Jersey are limited 
in outcrop to small areas near Long Branch in Monmouth County 
where a mixture of greensand and light-colored earth 11 feet in thick- 
ness and carrying Eocene fossils rests without apparent unconformity 
upon the “ash” marl of the Manasquan. ‘The conformity, however, 
is only apparent, well-borings indicating that the Shark River, as 
this formation has been called, probably overlaps the Cretaceous. 
