Geological Society. 4'61 



merate, which appeared between them on the opposite side, 

 being absent. 



In conclusion, the author traces this dyke of serpentine, 

 pursuing its course in a direct line to the N.E. and S.W. of 

 the locality in which it occurs on the Carity. It is found re- 

 curring at intervals for the space of at least fourteen miles from 

 the bridge of Cortachie to Bamff, near Alyth, in Perthshire. It 

 is always unconformable to the strata through which it passes, 

 and its course is never interrupted by any other rock. 



A notice was then read. On the serpentine of Predazzo ; 

 by J. F. W. Herschel, Esq. 



In this communication the author mentions that at Canzocoli, 

 near Predazzo, in the Tyrol, where a junction is seen of a 

 gi-anite-form sienite with dolomite, a layer of serpentine is 

 found to intervene between the sienite and the dolomite. 



The dolomite dips at an angle of 50° or 60= beneath the 

 sienite, and near the junction an alternation takes place in its 

 mineralogical character ; as it presents, instead of its usual 

 highly crystallized saccharine structure, a flaky and very 

 talcose appearance. The incumbent sienite is no less affected. 

 Its grain is smaller, and it is intersected with innumerable 

 veins parallel to the plane of junction, of a white mealy sub- 

 stance, which partly dissolves with effervescence, and partly 

 gelatinizes with nitric acid. In the midst of this white substance 

 occurs the thin lamina of serpentine, which is extremely well 

 characterized. The whole of the transition from the sienite 

 to the dolomite takes place within a diickness of about 18 

 inches or 2 feet. 



A notice was read. On carbonate of copper, occurring in 

 the magnesian limestone at Newton Kyme, near Tadcaster ; 

 by William Marshall, Esq. M.G.S. 



The green carbonate of copper, found by the author in a 

 large cjuarry of magnesian limestone near Tadcaster, runs 

 through the limestone in thin veins, dipping to the west, the 

 dip of the limestone being in the same direction, but at a less 

 angle. At Farnham, a small village two miles N. W. of Knares- 

 borough, which is also in the magnesian limestone, a conside- 

 rable quantity of copper was formerly obtained : and these are 

 the only two instances in which Mr. Marshall has heard of 

 any of the ores of copper having been found in the magnesian 

 limestone. 



June 3.— A paper was read, entitled " Remarks on qua- 

 druj)eds imbedded in recent alluvial strata ;" by C. Lyell, Esq., 



Sec. G.S. 



In a former communication to the Society, the author had 

 stated that he had found it dilHcult to explain the circumstances 



under 



