122 
I Assembly 
The sand of the tertiary is extensively used in the towns along the 
Hudson, in lime mortar, for walls, plastering, for laying pavements, and 
for brick making, and for moulding sand. For the latter use, it is worth 
25 cents per bushel, and sand banks for these various uses on the banks 
of the Hudson, are valuable. 
The gravel banks, also, when near the towns, are valuable, and yield 
a handsome revenue to their proprietors, for supplying earth for grading 
streets, filling, and for furnishing paving stones. 
The soils of the tertiary formation in these counties are good, and 
yield abundant crops. The land lies well for cultivation, and is easily 
tilled. Gypsum has been extensively applied on these soils, and with 
the aid of good cultivation, has rendered them very productive. It is 
to be hoped that the marls which exist abundantly in this region, will 
be applied as a substitute. The marl of the ponds and marshes is near- 
ly a pure carbonate of lime. Another, a clay marl, may be found al- 
most every where in tertiary formation, underlying the pebble and sand 
beds. It is the same as the clay used in the manufacture of bricks. It 
contains lime, and would be a good dressing on light soils. 
Trap Rocks. 
The general distribution of these rocks, and their position as over- 
laying the red sandstone, and as cutting through its strata in dykes, 
have been mentioned. They vary much in mineralogical character, from 
coarse crystalline to a perfectly compact greenstone, and from a slaty 
clinkstone to a coarse amygdaloid. The steep escarpments along the 
shore of the Hudson present a rude columnar aspect, without having 
any regular columnar forms. These cliffs have long been called the Pa- 
lissades — a name which most persons will acknowledge, is appropriate. 
Many facts of scientific interest were observed while examining these 
rocks. They will be detailed in the final report of the survey. 
The soil overlying the trap rocks, where it is deep enough for culti- 
vation, is rich and productive. The trap rock of the Palissades is ex- 
tensively used in New- York as a docking stone, and for foundations. 
It is not quarried from the cliffs, but the masses that have tumbled from 
the cliffs above, and formed a slope of debris, are transported on slight 
rail-roads to vessels on the shore. 
Jacob Voorhis has two of these quarries, from which he has shipped 
during the past season, about 100 sloop loads of 60 tons each, or 6,000 
tons of stone. 
