OF PRE-CAMBRIAN ROCKS 193 
base their recommendations for the correlation of these rocks in the 
several areas under discussion. 
II. ITINERARY OF THE COMMITTEE 
A. ITINERARY IN THE EASTERN ADIRONDACKS 
(Under the guidance of J. F. Kemp) 
The committee was summoned to meet in Whitehall, N. Y., on the 
night of July 4. The first week was devoted to areas which had 
been mapped by J. F. Kemp in or near the Champlain valley. July 
5 the committee, represented by Messrs. Adams and Kemp, reviewed 
first the green syenitic gneiss in the southwestern portion of Whitehall 
village, where a massive eruptive rock has become so granulated and 
platy from crushing and shearing that it strongly resembles sand- 
stone and is quarried like a stratified sediment. Next in the rail- 
way cuts north of Comstocks, garnetiferous, thinly foliated, micaceous 
gneiss was seen, which is believed to be sedimentary. The gneiss 
was penetrated both by red granite, now rolled out into thinly foliated 
gneiss with many leaves of quartz, and by a stock or small laccolith 
of gabbro, which had produced extraordinary rolls in the foliation. 
Two miles south of Comstocks and just east of the canal two strata 
of white, crystalline limestone were exposed, of which the lower is 
seventy-five feet thick, the upper much less. The limestones are 
associated with black hornblendic gneisses and with granitic gneisses 
of whose nature, whether sedimentary or igneous, it was not possible 
to positively decide. From their mineralogical composition they 
might be either, but the almost constant association with the lime- 
stones throughout the area creates a presumption in favor of sedi- 
ments. ‘The limestone exhibited interesting results of dynamic effects, 
in dragged and squeezed inclusions of hornblendic schist. In the 
area between the limestones and Comstocks was the basal Potsdam 
in a thin coat over the gneiss. 
The following day Messrs. Coleman, Cushing, and Speacer 
joined the others in Whitehall, and all proceeded by the north road 
across the neck between Lake Champlain and South Bay. The 
party observed the syenitic gneiss which is believed to penetrate 
the rusty and somewhat calcareous sedimentary gneisses, and were 
impressed with the faulted nature of the topography. Crossing 
