1856.] 



CHARTERS CLEAVAGE AT MONT LACHA. 



385 



2. Scrutineers were appointed, who, after the Ballot, reported 

 that Col. Portlock, K..E., F.R.S., was unanimously elected Presi- 

 dent; and tbat Hugh Falconer, M.D., F.R.S., was unanimously 

 elected a Member of Council. 



ORDINARY MEETING. 



Col. Portlock, President, in the Chair. 

 The following communications were read : — 



\. On a Section near Mont Blanc. 

 By Major S. Charters, F.G.S. 



[In a letter to Dr. Fitton, F.G.S.] 



On looking over an old note-book I found a Section which satisfies 

 me that Mr. D. Sharpe is correct in the view he has taken of the 

 cleavage. I send you a copy of it, which, if you have an oppor- 

 tunity, you may show him, — not that the observations of so unscien- 

 tific a geologist as I am can have any weight, but it may be satisfac- 

 tory to him, now that his paper has been attacked, to see that the 

 difference between cleavage and stratification, as exhibited at Mont 

 Lacha, attracted the attention of such a mere dilettante as myself, 

 now five years ago, — and that I scouted the idea of strata plunging 

 under the igneous rock that had upheaved them ; and that, until I 

 had made out the cleavage of Mont Lacha, I had attributed the 

 anomaly to reversal. 



M. Blanc. 





« 









JTh 



cS 



s 



•c 





o 



•SjvOJ 



d 



<u B 



^ 



S.E. a« 



"3 



Cm 

 O (D 





■ ^ 



o 



So 



Eh 



N.W. 



Crystalline schist. 



Anthraciferous schist. 



Crystalline schist. 



The dotted lines represent the lines of cleavage perpendicular to those of stratification, 

 which dip to the north-west at an angle of 75°. 



Ascending the torrent of La Gria, which nearly marks the sepa- 

 ration of the calcareous rocks of Mont Lacha from the crystalline 

 rocks of the Aiguille de Goute, we find a dark-coloured compact 

 limestone, the strata of which dip at an angle of 7^° to N.W. Pro- 

 ceeding further up the ravine, the calcareous rock becomes more 

 schistose, and frequently talcose. Belemnites and Ammonites^ in 



