DELESSE SACCHAROID LIMESTONE OF THE VOSGES. 19 



On the Saccharoid Limestone m the Gneiss of the Vosges. 

 By Prof. A. Delesse*. 



[Annales des Mines, 4 Ser. vol. xx. p. 141 et seq.'] 



The saccharoid limestone in the gneiss of the Vosges is met with 

 at Chippal, Laveline, Gemaingoutte, Wisembach, Sainte Marie, and 

 Sainte Croix aux Mines. It is always completely enveloped by the 

 gneiss, in which it forms irregular or lenticular masses, like those 

 which have been noticed as occurring in Scandinavia by MM. 

 Scheerer and Keilhau. These Vosges limestones have been inciden- 

 tally noticed by former writers, and are remarkable for the beauty 

 and great variety of the minerals they contain. 



Chippal. — The saccharoid limestone of Chippal, near Croix-aux- 

 Mines, forms an irregular mass, of 15 to 20 metres in width, and .50 

 in length ; and is enclosed in a schistose gneiss, which contains 

 quartz, orthose, and much brovvniish mica. The limestone is tra- 

 versed by a granitoid rockf, of a rose or brownish colour, granular 

 in structure, and almost entirely consisting of orthose-felspar. Being 

 much penetrated by calcareous matter, it effervesces strongly vdth 

 acids. The gneiss and limestone appear to have been brought to- 

 gether in a melted state and to have mutually interpenetrated each 

 other, the irregular granitoid veins being injected into the latter. 

 At its contact with the limestone the granitoid rock is edged, to a 

 thickness of several centimetres, with a hydrosilicate, which is green, 

 with a greasy lustre, softer than felspar, and often accompanied or 

 impregnated by quartz. This hydrosilicate is produced by an in- 

 cipient pseudomorphosis of the felspathic matrix of the granitoid 

 rock, and, from researches made by M. Delesse, appears to be nearly 

 allied to the pyrosklerite noticed further on. 



The line of separation between the limestone and the granitoid 

 rock is constantly marked by a kind of seam, which is intimately 

 connected with the limestone in the form of very thin laminse having 

 the structure of the hackee variety of quartz. These are seen by 

 dissolving the contact-surface of the limestone in acid. The laminae 

 are moulded in the interstices of the cleavage of the carbonate of 

 lime, which they represent in relief. 



The Chippal limestone is a fine white marble, crystalline and 

 lamellar, like the Paros marble ; sometimes, however, it is compact. 

 It is quarried for the marble-works of Epinal and for lime-burningi- 

 It is a pure carbonate of lime. ifi 



Several minerals occur in this limestone, especially in the quarries 

 on the upper part of the hill. They are sometimes disseminated 

 irregularly, sometimes they form series of nodules and druses or 



* The abstract here given of M. Delesse's detailed account of the Vosges lime- 

 stones forms a necessary accompaniment to the foregoing papers, on limestones in 

 crystalline rocks, by MM. Scheerer and Cotta {supra, p. 4 and p. 15), who appear 

 to have been induced to publish their observations by the publication of this 

 Memoir, and by communication with M. Delesse on the subject. 



t The relations of the limestone and the granitoid rock are shown in the plate 

 accompanying M. Delesse's Memoir. 



