38 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



formations). He remarks the huge blocks of granite and 

 schist which bestrew the exposed surfaces of the Scaglia rocks, 

 saying that they have been clearly carried here from Primitive 

 rocks exposed in the neighbouring Tyrol. But it remained for 

 a future age to penetrate the mystery of the transport of these 

 massive blocks by ice. Arduino's Monies tertiarii consist of a 

 younger and highly fossiliferous series of limestone, sand, marl, 

 clay, etc., and he observes that the materials of these can 

 in many cases be shown to have been derived from the 

 Secondary series. 



The volcanic rocks of Northern Italy were comprised by 

 Arduino in a separate group, and their different origin was 

 clearly pointed out; he included in the volcanic group not 

 only true lavas and tuffs, but also the fossiliferous strata with 

 which the volcanic rocks were interbedded. Arduino accord- 

 ingly referred the origin of the volcanic group to recurrent 

 eruptions and intermittent inundations of the sea. 



The first coloured geological map was published by Gottlieb 

 Glaser at Leipzig in 1775. Wilhelm von Charpentier published 

 three years later the Mineralogy of Chur-Saxony, which ranks 

 along with the works of Lehmann and Fiichsel as a classic in the 

 early geological literature of Germany. The distribution of the 

 principal rocks and formations is shown by means of colours 

 on a large map, and the occurrence of the less important 

 rocks, of mineral veins and volcanic dykes, is indicated by 

 various signs. 



Charpentier grouped granite, gneiss, mica schist, porphyry, 

 and limestone together as a basal formation belonging to one 

 and the same geological epoch. Above this basal formation 

 Charpentier distinguished argillaceous schists and slates, and 

 the greywackes of the Carboniferous series ; then the Flotz, or 

 ore-bearing group, which he sub-divided according to Lehmann 

 and Fiichsel. 



Some years later, by the discovery of Goniatites and fossil 

 plants in the slates and greywackes, Von Trebra, an overseer 

 of mines, was able to confirm Charpentier's conclusion, that 

 the true position of these rocks in the succession was above, 

 and not along with the basal formation. 



While the foregoing authors were conducting stratigraphical 

 researches in special localities, others were endeavouring to 

 enlarge our arena of knowledge by means of travel and by 

 observations of a more general character extended over wide 



