BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 28, pp. 431-450, PLS. 22-28 JUNE 18, 1917 



OIMGIX OF DOLOMITE AS DISCLOSED BY STAINS AND 

 O^IMlEli METHODS ' 



BY l-:i)\VAJ?D STI'JIDT.MANy 



{Prescnied before the Societfj Deceinher 28, 1916) 



CONTENTS 



Page 



rntrodiietioii 432 



The bases for iiifeieuees 432 



Aim and inetliod of study 432 



I'riiiciples underlying caleite and dolomite stains 433 



Facts sliowinjj: the lack of complete isomorphism between calcite and 



dolomite 433 



Methods of different! a tinj:; calcite and dolomite by stains 434 



Preparation of Lemberg stain 435 



Time of dolomitization 435 



Two h.^■potheses 435 



rost-emerg:ent dolomites., 435 



I*re-emerj^ent dolomites 435 



Evidence from stains and other metliods of direct study 4:55 



Publislied facts indicatinjj; the marine oriijin of the majority of 



dolomites 436 



Manner of marine dolomitization 440 



The processes 440 



Dolomitization hy the replacement of lime carbonate at the sea-bottom. 440 



J'hidences of i-eplacement 440 



Relations of dolomite .irrains to the bedding as shown by stains.. 440 



Kelations of dolomite to fossils 440 



Relations of dolomite grains to c^ach other and to calcite grains 



a.s shown by stains 442 



Relations of doUmiite to jKM-vions mai-ine sti-uctnres 444 



Dolomitization by recrystallization of MgO-bearing aragonite and cal- 

 cite skeletons 444 



Crystallization of dolomite from sea-waters permeating the sediments 



of the sea-bottom 445 



Direct precipitation of dolomite from the sea 445 



1 :Mauiiscript receivtMl hy llio Scerclary of' tlio Society .Tanuary 25, 1917. 



(431) 



