TOO W. N. Benson — Origin of Serpentine. 



plete, dehydration, which have ensued within the zone 

 of anamorphism. Examples of these products are peri- 

 clase, spathic magnesite, dolomite, siderite, breunnerite, 

 regenerated olivine, specular iron, magnetite, etc. " "In 

 regard to the term * Hydrometamorphism, ' whether in 

 the sense of Lindgren, referring to the action of meteoric 

 or vadose waters, or that of G. P. Merrill, to the action 

 of waters from deep-seated sources or from magmas, I 

 find no application for it below the belt of weathering. 

 There only has the highest hydration, below it every 

 change has been attended with a progressive loss of 

 water." "Even the remarkable rocks of the Stubach- 

 thal (discussed below) are explained in this manner." 

 "Antigorite and talc, crystalline and never colloid, have 

 merely served as insoluble fixatives to harden and record 

 the transformations of their mobile and protean prede- 

 cessors. Chrysotile is but a pseudo-fibrous variety of 

 antigorite, in fact a pseudomorph in antigorite, after a 

 pseudomorph in deweylite, after nemalite, the fibrous 

 form of brucite." 



While the writer must record his dissent from some of 

 these conclusions, it should be noted that Dr. Julien 

 closed his paper by stating : ' i The evidence in confirma- 

 tion of these views, from field, observations, optical exam- 

 inations, etc., together with a review of the literature of 

 brucite, serpentine, antigorite and the hydrous magne- 

 sian minerals, have been gathered for presentation in a 

 separate monograph." By Dr. Julien ? s lamented death 

 in the Titanic disaster, this record of extensive and 

 valuable observation has been lost to science. 



In 1891, Weinschenk stated that in the case of the ser- 

 pentine of the Stubachthal, primary antigorite occurred 

 intergrown with olivine, and had been formed from a 

 hydrous magma crystallizing under high pressure, and 

 that further the water emitted from the magma on con- 

 solidation converted the remaining olivine into secondary 

 antigorite. The distinction made between these is that 

 the primary antigorite (which is admitted to be very 

 rare) occurs in large well-formed plates regularly inter- 

 grown with the olivine, generally parallel to the dome- 

 face, while the secondary antigorite forms more or less 

 irregular fine scaly aggregates. Moreover, there occur 

 sharply defined veins of coarsely granular olivine and 

 antigorite, which were injected after the serpentinization 



