1859.] 



MURCHISON NORTH HIGHLANUS. 



221 



section, fig. 4, drawn and sent to me by Prof. Harkness, confirms 

 distinctly my view of the limestone being merely a subordinate part 



Fig. 4. — Section South-ivest of Cnoc-an-drein. Inchnadamjiff. 

 W.S.W. E.^.E. 



1. Lower Limestone, cherty. 



2. Thick- bedded white quartz-rock. 



3. Purple quartz-rock, with Serpulites. 



4. Tldn limestone. 



5. Tliick-bedded quartz-rock. 



of the quartz-rock series. He has detected one thin course of 

 limestone at the spot indicated, above the Manse of Inchnadampff. 



By walking along the summit of Cnoc-an-drein, and about 150 

 feet above the limestone, I observed in one spot a small portion of 

 apparently intrusive felspar-rock ; but it bad no persistence right or 

 left, and did not affect the dip of the strata, any more than the 

 syenitic greenstone in the heart of the limestone. Continuing this 

 section, however, the upper quartz -rock is soon seen to be affected 

 by a down-cast fault on the east ; though the strata, rising with a 

 reversed inclination, are seen, as in fig. 3, to be the same as those 

 to the west of the fault, as they also exhibit a pink tint*, and contain 

 similar Annelide-tubesf. Thence the upper quartz, which is a con- 

 tinuation of tbe chief mass of the adjacent lofty mountains, including 

 Ben More of Assynt, undulates for great distances to the east-by-north, 

 and finally in Kinloch-Ailsh dips under another limestone covered by 

 mica-schists and gneissose strata, of which hereafter. 



I have first dwelt on the parts of this section near Inchna- 

 dampff to show, first, that igneous rocks included in the heart of the 

 limestone and overlying quartz-rock do not operate as lines of se- 

 paration ; and secondly, that the first notable fault which can be 

 detected is not between the lime-tune and the overlying strata, but 

 is actually within the upper quartz itself J. It will presently be 

 shown that such faults are very numerous, and arc quite irrespect- 

 ive of the ago of the deposits. Several of these were laid down, 



* This distinction of colour is purely local ; for the upper quartz also 

 weathers while over large area*. 



t Since the memoir was read, more extended and more perfect evidences of 

 the existence of these large Sea-worms or Annelida* have bean found in the hard 

 quartz-rocks of the l<>fty mountain of Fionsvin (porous quarts-rook), by thi 

 of Mr. Clark of Eriboll. These burrows, many inches deep, and ss large as a 

 man's Bnger, resemble oloeeh those made bj the great lob- or lug-worm of the 

 fishermen (Arenicota piacatorum\ and, bji the arrangement of the once sandy 



matt-rial, afford evidence of the Upward and downward movement* of the ancient 

 worm. They are for the mOSl purl i" pain, like those \1111elide- >.i well de- 



Bcribed bj Mr. Binney from the paving-flags near afanohi 



} Bee Professor Niool'e statement, thai a great fault oooun between the lime* 

 stone and the upper quarts; and ma diagram, bringing up the older quarts on 

 the dip-side of the limestone (Quart Joura Gfool, Boa fol \iii. p. 2 



