J. G. Goodchild — Granite Junction in Mull. 447 



that the time has yet come for doing so. The work which I have 

 done in the Lake District, both alone and with Prof. Nicholson and 

 Mr. Harker, is merely preliminary to the elucidation of the general 

 history of the district. Much remains to be done, both by careful 

 microscopic study of the rocks and by examination of all the 

 available fossil evidence, before the full history of the rocks of the 

 Lake District and adjoining areas can be written. Mr. Goodchild 

 has given us his interpretation, though without full discussion of 

 the palseontological evidence.^ Whether that interpretation is correct 

 time alone will show, but in the meantime I shall bow down to no 

 conclusions which, are not fully supported by the evidence of the 

 fossils, for the past history of geology shows us the errors which 

 have arisen from misinterpretation of such evidence. 



IV. — Note on a Granite Junction in the Ross of Mull. 



By J. G. Goodchild, F.G.S. ; 



of Her Majesty's Geological Survey. 



[Communicated by permission of the Director General of the Survey]. 



IN a review of Nicholson's " Geology of Cumberland and West- 

 moreland," which appeared in the Geological Magazine about 

 a quarter of a century ago, the reviewer observes, in I'eferring to some 

 remarks upon the Shap Granite, that this and other granites have 

 clearly taken the place of the rocks whose position they occupy, and 

 that, in fact, intrusive rocks can be shown, in a great majority of 

 instances, to have replaced, rather than to have displaced, the rock 

 masses which they invade. The reviewer's identity with a well- 

 known Professor of Geology at one of the English Universities is 

 sufficiently evidenced by his intimate acquaintance with the geology 

 of British Silurian and Cambrian rocks.'^ Like much else that has 

 emanated from the same source these particular observations were 



^ In support of this statement, I may quote a remark made by Mr. Goodchild in 

 a paper read before the Geologists' Association on July Sth, 1889, in which he 

 refers to the paper by Professor Nicholson and myself on the Stockdale Shales. 

 " If we listen to our palseontologists we must classify the Graptolitic Mudstones 

 with the Ordovicians ; while, if we are guided by the physical evidence alone, then the 

 Graptolitic Mudstones with their Ordovician fauna must go in the same group with 

 the beds above, and be classed as Silurian." If Mr. Goodchild had studied our 

 paper, he would have discovered that the Graptolitic Mudstones (there called the 

 Skelgill Beds) do not contain a single Ordovician form, with the possible exception 

 of Climacograptus normalis. Again, in the same paper Mr. Goodchild states that 

 during the accumulation of the Browgill Beds ' ' deep oceanic conditions prevailed, 

 and the old colony of graptolites either migrated still further, or else it became 

 completely extirpated here." A glance at our paper would have shown that two 

 well-marked graptolitic zones occur in the Browgill Beds of the Cross Fell area, 

 and that the graptolites of these zones are intermediate between those of the Skelgill 

 Beds and those of the Lower Coniston Flags, which according to Mr. Goodchild 

 "migrated from a diiierent zoological province!" Mr. Goodchild's depressions, 

 elevations, and migrations belong to a past generation who made much of " Colonies " 

 and similar ingenious explanations ; but it is refreshing to meet with them again, 

 after the accurate work on Graptolites of Lapworth, Linnarsson, Tullberg, and 

 others. 



^ A reference to the same phenomena is given in the Geological Survey Memoir on 

 the Sedbergh District, in connection with some minette dykes there. 



