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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 31. 



line of foliation. In the different beds of limestone I did not observe 

 any mica whatever. 



(Case 8.) — On the other side of Christiansand, about five miles 

 from the town, west of Torresdale River, we have very extensive beds 

 of a white crystalline limestone, very similar to, and foliated like, the 

 last-mentioned. A section is seen in fig. 4, and represents a quarry 

 near the top of a mountain called Pusaasen. 



Fig. 4. — Section of gneiss and limestone at Pusaasen Mountain, 

 near Christiansand, Norway. 



a. Granitic gneiss ; not distinctly foliated. 



b. Quartzose, brownish, foliated gneiss. 



c, c. White, crystalline, foliated limestone (about 15 feet exposed). 

 ■r, x. Indeterminable broken and weathered mass, filling joint. 



The section is taken about parallel to the strike, or 40°N."W.--S.E. 

 The strata incline towards the south, and dip at 15° S.W. At the 

 top of the section on the north side we have a considerable mass of 

 gneiss (a), without a grain (or nearly granite-gneiss), with no foliated 

 arrangement apparent, very quartzy, and containing but very little 

 mica. This abuts against a bed of very quartzy gneiss (Z>), where the 

 lines of the foliation give the appearance of its having been doubled 

 up. This gneiss contains numerous crystals of iron-pyrites in the 

 lines of foliation, and by their oxidation it has acquired a rust-brown 

 colour. Between these two gneiss rocks we have a joint filled up 

 with a broken, decomposed, and weathered mass (x), of undistin- 

 guishable character ; but below the whole is a large bed of white 

 crystalline limestone, foliated by lines of augite-crystals, precisely as 

 in the last case ; the foliation is here parallel to the upper and lower 

 surfaces, or the foliation, of the gneiss above it. About 15 feet of 

 the limestone bed is uncovered ; the lower 3 feet is coarser-grained 

 than the upper 12 feet. At a few spots mica is seen present, foliating 

 the limestone in a similar direction. 



(Case 9.) — On the same side of the Torresdale River, and about 

 two miles west of the last locality, can be seen an extremely interesting 



