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THE 



AMERICAN JOURNAL OF SCIENCE 



[FIFTH SERIES.] 



I 



Aet. I. — Relations of Subjacent Igneous Invasion to 

 Regional Metamorphism; by Joseph Baeeell.^ 



CONTENTS. 

 Summary. 



Part I. Eegional relations. 

 Introduction. 



Subjacent igneous invasion in mountain provinces. 

 Underground extension of Cordilleran batlioliths. 

 Batholiths of New England- 



Eelations in New England between batholithic and metamorphic limits. 

 Preliminary statement. 



The pre-Newark floor of the Connecticut Triassic. 

 The section across southwestern Connecticut. 

 The section across northwestern Connecticut. 

 Lack of metamorphism in Pennsylvania folds. 

 Part II. Metamorphic and metasomatic relations of orogenic batholiths. 

 Heating and crystallizing effects of magmas. 

 Chemical or metasomatic effects of emanations. 

 Prevention of deep penetration of meteoric waters. 

 Development of anhydrous or hydrous silicates. 

 Silication in relation to igneous intrusion. 

 Eelation of magmatic gases to atmosphere and ocean. 

 Limited depth of zone of anamorphism and rock flow. 

 Part III. Interpretation of dynamo-metamorphic features in the roofs of 

 batholiths in mountain provinces. 

 Preliminary statement. 



Features produced by movement of solutions and selective crystallization. 

 Development of lit-par-lit structure by the force of crystallization. 

 Development of banded orthogneisses as a result of successive injections. 

 Eejuvenescent and decadent stages of injection. 

 Alternatioii of injection and mashing. 



SUMMARY. 



[In summary, evidence is presented (Part I) that 

 batholithic invasions widen downward and may occur 

 close below many rocks where they have not been sus- 

 pected. 



^ This paper was written by Professor Barrell apparently in the year 1913 

 or 1914. He later added some marginal notes and rearranged it, but never 

 put it in finished form. He had mentioned to me certain plans for using the 

 material and on the basis of those statements and the marginal notes, I have 

 edited the manuscript. It is evident from his notes that he planned a re- 

 arrangement to include definitions given by other authorities. This I h^ive 

 attempted, putting in brackets all the essential parts which have been added. 



Frank F, Grout. 



Am. Jour. Sci.— Fifth Series, Vol. I, No. 1. — January, 1921, 

 1 



