BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



VOL. 11, PP. 461-474, PLS. 43-49 JUNE 30, 1900 



THOMSONITE, MESOLITE, AND CHABAZITE FROM GOLDEN, 



COLORADO 



BY HORACE B. PATTON 



{Read before the Society December SO, 1899) 



CONTENTS 



Page 



Work of previous investigators 461 



Place and mode of occurrence , 462 



Thomsonite 463 



General description 463 



Type I 464 



Type II 466 



Type Ila 466 



Type III .467 



Type Ilia 467 



Mesolite 468 



Chemical analyses 469 



Chabazite 470 



Other zeolites 472 



Analcite 472 



Apophyllite 472 



Stilbite and laumontite 472 



Calcite and aragonite 473 



Order of deposition 473 



Summary 473 



Work of Previous Investigators 



The zeolites of North and South Table mountains at Golden, Colorado, 

 have already become known to mineralogists mainly through the ex- 

 cellent descriptions of these minerals and of their occurrence by Cross 

 and Hillebrand in Bulletin 20 of the United States Gelogical Survey.* 

 In this bulletin the above named authors f have given a brief description of 



* Contributions to the Mineralogy of the Rocky Mountains, Bull. no. 20, U. S. Geol. Survey, 

 f A briefer, preliminary paper by the same authors was published in Am. Jour. Sci., 3d ser., vol. 

 xxiii, 1882, p. 452, and 3d ser., vol. xxiv, 1882, p. 129. 



LXVI— Bull. Geol. Soc. Am., Vol. 11, 1899 (161) 



