BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 5, pp. 259-280 March 3, 1894 



GEOLOGIC ACTIVITy OF THE EARTH'S ORIGINALLY 



ABSORBED GASES 



BY ALFRED C. LA^'E 



{Read before the Society December 28^ 189S) 

 CONTENTS 



Page 



Introduction 259 



Scope of the Paper 261 



Synopsis of Argument 261 



Relative Importance of Points discussed 262 



Absorbed Gases 262 



Given off rather than combined 262 



Their Nature 262 



Importance in Crystallization of plutonic Rocks 264 



Deep-seated Cracking 265 



Its mental Conception difficult ' 265 



Direct Evidence as to its Occurrence 266 



Its Possibility a priori 267 



Its Production by Stresses 268 



Explanatory of volcanic Phenomena 2<)9 



Igneous Phenomena and Causes 270 



Increasing Heat and Basicity toward Earth's Center 270 



Chemical Complexity of igneous Rock Series 271 



Source and Diminution of acid Eniptives 272 



Contact Zones 272 



Intrusive Rocks , 272 



Textures of Rock . 273 



Formation of Veins 273 



Magmatic Zones 274 



Relation of Depth and increasing Pressure and Temperature 274 



Probable Reactions of gas-making Elements 276 



Basis of Kock Classification 277 



Other possible Activities of Ab.sorbed Gases 278 



Suggested Lines of In(iuiry 279 



Comments 279 



Introduction. 



In view of the fact that one or two friends have spoken to me of this 

 paper as propounding oriojinal theories, a word of personal explanation 



XXXVI -Bull. Geol. Soc. Am., Vol. 5, 1893. (259) 



