xliv PROCEEDINGS OP THE GEOLOGICAL SOCIETT. 



of Santorin. It results that this eruption brings to Kght acidic as 

 well as basic rocks — and, indeed, the former in the beginning, and 

 the latter during the later stages of the eruption. 



" The renowned ore-bearing localities of the trachyte masses of 

 Schemnitz and Ej^emnitz have offered us likewise the opportunity 

 for comprehensive study. "Whilst Baron von Andiian surveyed the 

 geological phenomena of the country with greater exactness than had 

 -hitherto been the case, Bergrath Lipoid occupied himself with the 

 lodes themselves and the mining. A detailed monograph, printed 

 in the third number of our Jahi'buch for 1867, gives, along with a 

 geographical and geological review, a comprehensive statement of 

 the history of the Schemnitz mines, and, further, a complete descrip- 

 tion of all the lodes ; which appear partly in Rhy elite (at Konigsberg), 

 most abundantly in Greenstone trachyte and Dacite, but partly also 

 in Syenite. 



" But beyond those districts in which our detail surveys were at 

 work I have manifold labours to mention, which partly refer to 

 those portions of the country that had been earlier surveyed, and 

 enlarge our knowledge of them, and partly concern some districts 

 that had not yet been examined. The former of these have had a 

 special tendency to break up those great groups of sedimentary rocks 

 which were separately laid down in the maps of our survey, and to 

 correlate them with the subdivisions of the formations determined 

 outside the district of the Alps and Carpathians. In fact these in- 

 quiries have given proof that, at least in many cases, a parallel of this 

 sort may be carried much further than had hitherto generally been 

 believed. 



" With regard to the Alp-country I may here refer to the important 

 observations furnished by D. Stur* ' On the Occurrence of Silurian 

 Possils at the Erzberg, near Eisenerz, in Styria,' which gives not 

 only a very welcome further proof of the Silurian age of the Grey- 

 wacke zone of the iSTorthern Alps, but also allows us to assume the 

 presence of several successive zones in this formation, — 



" Also to the observations of Peters and Klav ' On the Devonian 

 Formation of the neighbourhood of Gratz 'f, fi^om which it appears 

 that in all probability the three divisions (the Lower, the Middle, 

 and the Upper Devonian) are represented, — 



"And to the labours of Suess and Mojsisovics on the Trias, Rhagtic, 

 and Lias formations in the Salzkammergut J, which attempt a highly 

 detailed arrangement of these formations, and, as an example, show 

 the Lias zone of the Ammonites planorhis and the A. angulatus, &c., 

 in a manner completely agreeing with occurrences beyond the Alps. 

 Some of these views are opposed by Mr. D. Stur§; whilst, on the 

 other hand, the accepted division of the Rhsetic beds has received 

 satisfactory confirmation in the researches carried out by Dr. Schlon- 

 bach in the neighbourhood of Kossen ||. 



* Jahrb. d. geol. Eeichsanstalt, 1865, p. 267, Yerh. p. 261 ; 1866, Verh. 

 p. 58. 



t Bid. 1867, Verh. p. 25. + Ihid. 1866, Verh. p. 158. 



§ md. 1866, Verh. p. 175. || Ibid. 1867, Verh. p. 211. 



