94) Mr Ainsworth 071 the Physical Geography 



An examination of the geognostical structure of tlie Malvern Hills offers 

 the following positions : 



liY, That, throughout the whole range, the various rocks entering into the 

 composition of the mountain-masses contain no organic remains. 



2d, That in no place are they found superimposed on, or alternating with, 

 rocks containing organic remains, or which, from mechanical analysis,' 

 are known to be formations deposited subsequent to the appearance 

 of organization. 



From the most northerly point to as far as their structure can be investi- 

 gated in the south, they present an uniform series of primitive rocks, from 

 highly crystalline granite to the more compact chlorite-slate ; and the transi- 

 tions between these two rocks may, with a little patience of research, be traced 

 throughout all their gradations ; — not that these gradations occur exactly in 

 accordance with the relative situation of the mountain-masses, but that, in 

 particular localities, such transitions are distinctly marked out. The central 

 part of the range, comprising the Herefordshire Beacon and its table land, 

 the hill extending to the north to Whyche road, and the hill above Eastnor 

 Wood to the south of the Beacon, arc all composed of granite, with slight lo- 

 •cal variations of texture. Dr MacCuUoch has remarked, that specimens may 

 frequently be obtained from beds of gneiss, undistinguishable from genuine 

 granite, an example of which he mentions as occurring in South Uist ; and fur- 

 ther remarks, " that the views of the geologist, embracing a wide field, must 

 not be limited by variations which are minute, irregular, and inconsistent, and 

 which do not affect the broader principles that regulate his investigations." 

 However just these remarks may be, they admit of too much latitude of ex- 

 pression to accord with the severe science of a philosophy founded on obser- 

 vation alone. From the slaty appearance Avhich these rocks sometimes pre- 

 sent, — ^from the general tendency which, throughout the whole mountain 

 range, they show towards assuming the appearance of gneiss, the more crys- 

 talline portion of the series might be considered as mere varieties of that for- 

 mation. This suggestion I would, however, strongly oppose. To assign the 

 proper denomination to a rock whose connexions and mechanical texture offer 

 distinctive and recognizable characters, is a basis to all strict geognostical 

 science. When, therefore, we find a rock in all its characters a representa- 

 tive of granite, assuming the highest situation in the range, independent in 

 itself, and only varying through gradual transitions into subordinate forma- 

 tions, it becomes a genuine granite, and in situation and chemical constituents 

 marks itself out as the oldest rock and basis of the mountain range. Its in- 

 vestigation in situ is interesting, and affords in its localities very marked dis- 

 tinctions. The hills which it forms, though bold and rugged in their outline, 

 are nevertheless the most rounded at their summits of any in the range. 

 The Herefordshire Beacon, which I have already mentioned, may be divided 

 into two summits, each having the remains of a Roman encampment on it, 

 as well as the neighbouring southern hill, formed of a red granite, in which 

 flesh-coloured felspar is by far the most abundant ingredient, mica being a 

 rare component, and often entirely wanting. The whole rock appears so liable 

 to decomposition, that near Eastnor Wood it is quarried and sieved for gra- 

 vel It bears a great analogy to the red granite met with between Loch 



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