(/) '; 'l'^^^AL of THE 



canic outbreak, and ciuniit)- at least one period oi inactiv- 

 ity sedimentary ^Intc^ (tin- Monroe slates') were depos- 

 ited. 



These acid volcanics are accompanied by pyroclastic 

 breccias and basic eruptives. The basic rock^ are of 

 dark ^-reen color, and are perhaps pyroxenic in composi- 

 tion. They cover lar<^-e areas, and are often massive or 

 only partlv schistose; ag-ain the}^ are lar^^ely sheared into 

 schists. It is quite probable that most of the cJiloriiic 

 schists in this part of the Carolina Slate Belt are of this 

 nature. 



The breccias c;)n-iisL (A this basic material in which are 

 imbedded angular fra^ments/)f the lelsite (apo-rhyolite) 

 or pori)hyry up to one 'foot in diameter. Thev are dis- 

 tinctly pyroclastic breccias and hence the basic rock, or 

 ])<)rphyrite as it may be j)rovisionally called, is later than 

 the quartz pbri)hyries and rhyolites. This would a^-ree 

 with the ij-enerally accepted law of eruptions, i. e. from 

 tlie normal to the acid to the basic types. 



Kmmons, in his description of the Upper Taconic, men- 

 tions brecciated coni*-lomerates as the most remarkable 

 mass of this division. As he states, "It has an aroilla- 

 ceous or chloritic base. The mass is composed in the 

 main of fra^i'ments of other rocks, mostly retaining- an ant>-- 

 ular form; but frequently rounded and worn rocks are 

 enclosed in the mass. The fra^'ments are sometimes 18 

 inches and even 2 feet lon^-." (p. 59.) 



Kerr mentions brecciated and con^domerated (siliceous 

 slates, the pebbles sometimes a foot and upwards in di- 

 ameter, frequently chloritic and often passino' into horn- 

 stone and chert, and occasionally into quartzite" [p. 60]). 

 That these rocks correspond to the above described pyro- 

 cla.^tic breccias is at once evident. 



These ancient volcanics have also been found coverinff 

 lar<j;e areas in Chatham and Orange counties, near the 

 eastern ed^e of the Carolina Slate Belt, and full}^ 40 

 miles east of the re^'ion int;ludino- the above described 



