QUATERNARY DIVISION. 125 
The various facts collected in the First Geological District, and inferences from those facts, 
having reference to this formation, will be related under the following heads, viz. 
(a) . External and chemical characters of its various members. 
(b) . Topographical and agricultural characters. 
(c) . Range, extent, elevation, thickness, and terraces. 
(d) . Economical applications, and mineral contents. 
(c). Phenomena of water and springs; formation of valleys, slides, faults and wrinkling of the strata. 
(/). Direction and strength of currents engaged in depositing the different members, and the condition 
of this part of the earth’s surface at the quaternary period. 
(a). External characters. 
This formation is composed of three, and in some places of four distinct members, viz. 
gravel, sand, grey or buff-colored clay, and blue clay. The blue clay rests on a bed of gravel, 
boulders, hardpan, or on the underlying rock in place. The sand and gravel are mostly sili¬ 
ceous, but contain some feldspar, mica, magnetic iron-sand, garnet sand and epidote. The 
sand on the surface is nearly white, or slightly buff-colored, in consequence of the rain and 
surface waters having gradually dissolved out the oxide of iron, and transported it to the de¬ 
pressions and swamps, where it has accumulated to form bog iron ore. Where water oozes 
through the sand in contact with air, the sand is usually stained with the hydrated peroxide of 
iron (limonite). The causes of the solution and deposition of the oxide of iron have already 
been explained under the alluvial deposits. The sands and gravel, at a little depth below the 
surface, are striped, and show the direction and force of the currents from which they were 
deposited ; and by means of the materials of which they are composed, we can, in some in¬ 
stances, ascertain from whence the materials were derived. The usual color of the sand has 
been mentioned, but opposite New-Haven, and on the west part of Long island, some beds 
of sand and clay are red, or brownish red, derived from the redsandstone. Concretions of 
sand, cemented sometimes by calcareous matter, and sometimes by oxide of iron and oxide 
of manganese, are found in these beds ; and others of a tubular form, and cemented, it is said, 
by a partial fusion, where lightning has struck the earth. 
The sandy calcareous concretions, sometimes like a bunch of grapes, and other imitative 
forms, have been occasionally found around Newburgh bay above the Highlands. Some of 
these were in the Cabinet of the Lyceum of Natural History of West-Point. Those cemented 
by oxide of manganese were found by myself, near the brick-yards in the sand-banks over- 
lying the clay beds on West neck in Huntington, Long island, and at the localities of figures 
10 and 13, Plate 4. Specimens are preserved, and are in the State museum in the Old State 
Hall, Albany. It is possible that the sand beds on West neck just alluded to, may belong to 
the tertiary. The evidence thus far obtained is not sufficient to decide the question. 
Lumps of white clay were frequently seen imbedded in the sands of the south part of Long 
island, along the route of the Long-Island railroad, where the excavations had exposed them, 
in Jamaica, Hempstead and Oysterbay townships. 
