434 REPOET ON NATIONAL MUSEUM, 188(). 



Meriden, in Connecticut; the ralisndes along- tlic Hudson Tiiver, in New 

 York ; Bergen Hill and otlier elevations in New Jersey. 



" In Nova Scotia trap ridges skirt the whole red-sandstone region and 

 face directly the Bay of Fundy ; Cape Blomidon, noted for its zeolitic 

 minerals, lies at its northern extremity on the Bay of Mines. 



" In Connecticut the ridges and dikes are extremely numerous, show- 

 ing a vast amount of igneous action. * * * They commence near 

 Long Island Sound, at New Haven, where they form some bold emi- 

 nences, and extend through the State and nearly to the northern bound- 

 ary of Massachusetts. Mounts Ilolyoke and Tom are in the system. 

 The general course is parallel to that of the Green Mountains. 



"Although the greater part of the dikes is confined to the sandstone 

 regions, there are a few outside, intersecting the crystalline rocks and 

 following the same direction, and i^art, at least, of the same system. 



"Even the little Southbury Triassic region, lying isolated in western 

 Connecticut, has a large number of trap ridges, and such a group of 

 them as occurs now^here else in New England outside of the Triassic. 

 Their direction and x>ositious in overlapping series are the same as in 

 the Connecticut valley. 



"The trap usually forms hills with a bold columnar or front and slop- 

 ing back. When nearly north and south in direction the bold front is to 

 the westward in the Connecticut Valley, and to the eastward in New 

 Jersey. It has come up through tissures in the sandstone, which varied 

 irom a few inches to 300 fet^t or more in breadtli. In many cases it has 

 made its way out by opening the layers of sandstone, and in such cases 

 it stands with a bold front, facing in the direction toward which it thus 

 ascended." 



Connecticut. — The extensive diabase outcrops noted above as occurring 

 at East and West Rocks, north of New Haven in this State, are (piarried 

 ibr foundation walls and for leaving purposes in the near vicinity. The 

 rock is too dull in color for oi'uamental work. 



Maine. — Diabase is quarried at three localities in this State, Addison, 

 Vinalhaven, and Tenant's Harbor. At Addison the rock occurs in ex- 

 tensive outcrops close by the water's edge. Single blocks 00 by 10 by 

 20 feet have been moved in the quarries, and natural blocks 00 by 10 by 

 J 5 feet occur. The chief defects in the stone are said to be the so-called 

 " knots," Avhich consist of irregular patches of coarse feldspar and dark 

 crystals of hornblende. There are also occasional seams, causijig the 

 rock to split unfavorably. The rock is moderately tine grained, very 

 dark gray, sometimes almost black or spotted bla(;k and white on a 

 polished surface and of a tine ai^pearance. It has been used in the walls 

 inclosing the Capitol grounds at Washington, in the construction of a 

 bank at Montreal, and is quite generally used for monuments in Boston, 

 New York, Brooklyn, Washington, Montreal, and (JuebcM;. The Vinal 

 haven diabase is less extensively worked on account, of its hardness 

 It is of fluer grain than the Addison stone and uniformly dark-gray^ 



