BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 VOL. 16, PP. 347-366, PL. 65 MAY 31, 1905 



COCKEYSVILLE MARBLE 



BY EDWARD B. MATHEWS AND W. J. MILLER 



(Read before the Society December 30, 190 Jf) 

 CONTENTS 



Page 



Introduction 347 



Rocks of the region 348 



List of the formations 348 



Baltimore gneiss 348 



Setters quartzite 349 



Cockeysville marble 349 



Wissahickon schist 351 



Igneous rocks .... 352 



Areal distribution of the rocks 352 



In general 352 



Distribution of Baltimore gneiss 352 



Southern area 352 



Northern area 353 



Distribution of Setters quartzite 354 



General characteristics of the exposures 354 



Southern area 354 



Northern area 355 



Distribution of Cockeysville marble 357 



Areas in general 357 



Greenspring valley 357 



Dulany valley 358 



Worthington valley— Butler area 359 



Distribution of Wissahickon formation 360 



Structure 361 



General characteristics 361 



Folding 362 



Faulting 363 



Introduction 



In earlier papers * the senior author has presented an interpretation 

 of the structure of the Piedmont region as exhibited in Maryland, and 



*Amer. Jour. Sci., 4th ser., vol. xvii, pp. 141-159, 1904; see also paper in this volume, pp. 329-346. 

 Xf.VII-BuM,. Geol. Soc. Am.,Voi,. 10,1904 (347) 



