208 =f. D. Dana—Taconic Rocks and Stratigraphy. 
jectural, because the surface is to so large an extent earth- 
covered, or have the rocks displaced by growing forest te 
Good outcrops of the schist and limestone are oun 
they largely fail along the limits between the formations, w 7 
of most interest, because these limits are generally nee : 
base of the ridges, and there the limestone has usually een 
worn away and concealed by the action of descending waters; 
and not unfrequently has become the bottom of a marsh. ie 
Outcrops along the limits between the quartzyte and ae as 
are still more rare, because very much of the quartzyte 
b. General geological characteristics of the Taconic region. 
: ] 
By way of introduction, I here briefly state the gene™ 
geslogind dust sade of the region as deduced from my 
present knowledge of the facts. : ‘de and 
a. Lhe most striking geological feature is the wide hic) 
complicated distribution of the crystalline (or cy ae 
limestone formation in north-and-south lines. se orth- 
marked topographical feature is the existence of bee alleys 
ward trending plains or valleys and narrower parallel v 
