152 A. F. BUDDINGTON 



Avondale Volcanics owe their formation to metasomatic replace- 

 ment and alteration of previously silicified rhyolites or rhyolitic 

 volcanics by thermal waters, under conditions of dynamic stress 

 and intermediate temperatures and pressures, operating along 

 channels primarily determined by fault or shear zones. Chemi- 

 cally, the salient features of these alterations have been the intro- 

 duction of alumina, the more or less complete substitution of the 

 hydroxyl element in place of the alkalies, and the solution of soda. 

 The solutions instrumental in causing these alterations may have 

 been to a greater or less extent juvenile waters emanating from 

 the intrusive granite batholith and monzonite stock at some 

 period subsequent to the time of their injection. 



May, 1 91 5 



BIBLIOGRAPHY 



Bell, W. H. "New Localities for the Mineral Agalmatolite with Notes on 



Its Composition," Miner : Mag., VII (1887), 28. 

 Chrustchoff, von K. "Artificial Zircons," abstract in Miner. Mag., X (1894), 



259- 

 Clapp, C. H. " The Geology of the Alunite and Pyrophyllite Rocks of Kyuquot 



Sound, Vancouver Island," Summary Rept. of the Geol. Surv., Dept. of 



Mines, for igij (1914), pp. 109-26. 

 Clarke, F. W. "Data of Geochemistry," U.S. Geol. Surv., Bull. 4Qi (1911), 



P- 567- 

 Cole, G. A. J. "On the Alteration of Coarsely Spherulitic Rocks," Quart. 



Jour. Geol. Soc, XLII (1886), 186-87. 

 Crosby, W. O. "Pinite in Eastern Massachusetts, Its Origin and Geologic 



Relations," Am. Jour. Sci., 19 (1880), 116. 

 Dana, E. S. A System of Mineralogy (1909), p. 691. 

 Hillebrand, W. F. Quoted by H. W. Turner (1895). 

 Howley, J. P. Geologic Map of Newfoundland (1907). 

 Lacroix, A. Mineralogie de la France (1895), I, 471. 

 Le Chatelier, M. H. "De TAction de la chaleur sur les argiles," Bull. Soc. 



Min. France, X (1887), 207. 

 Powers, F. D. "The Pambula Gold Deposits," Quart. Jour. Geol. Soc, 



XLIX (1893), 233-35- 

 Pratt, J. H. "Talc and Pyrophyllite Deposits in North Carolina," N.C. Geol. 



Surv., iqoo, Economic Paper No. 3, pp. 23-29. 

 Turner, H. W. " Further Contributions to the Geology of the Sierra Nevada," 



U.S. Geol. Surv., 17th Ann. Rept., 1895. P art 1, P- 529. 



