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I.—Four Theories of the Age and Origin of the Dartmoor Granites

Published online by Cambridge University Press:  01 May 2009

A. K. Hunt
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Extract

Four Theories of the Age and Origin of the Dartmoor Granites have been lately current, viz.:—

(1) The ordinary Plutonic of Sir H. de la Beche.

(2) The Laccolitic-Plutonic of Mr. W. A. B. Ussher.

(3) The Volcanic of Mr. K. N. Worth.

The above all assume the exclusively post-Carboniferous age of the granite, owing to its intrusion into the adjacent Carboniferous rocks;one of the best attested facts in geology.

(4) The combined pre-Devonian non-intrusive and post-Carboniferous intrusive (both plutonic), advanced by myselfin1889.

Mr. Ussher has recently withdrawn his provisional laccolitic hypothesis, on stratigraphical grounds,infavour of one which is practically equivalent to No. 4.

As it is impossible to compress the work of some four years into a magazine article, the present paper must be confined to a sketch of my main argument.

My friend Mr. Worth has, with characteristic generosity, lent me the diagrammatic woodcut illustrating bis ideal volcano;accompanied by the following remark:“Please do not limit your views of me;you owe it to yourself to make your case as strong as possible, and we shall not differ outside our theories.”A too generous opponent indeed, and one hard to oppose.

Type
Original Articles
Information
Geological Magazine , Volume 1 , Issue 3 , March 1894 , pp. 97 - 108
Copyright
Copyright © Cambridge University Press 1894

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References

page 97 note 1 Trans. Devon. Assoc. vol. xx p. 154.Google Scholar

page 97 note 2 “The Dartmoor Volcano,”Trans. Plymouth Institution, etc., 1888–1889.Google Scholar

page 97 note 3 Trans. Devon. Assoc. vol. xxi. p. 238.Google Scholar

page 97 note 4 Trans. Devon. Assoc. vol. xx. p. 156.Google Scholar

page 97 note 5 Proc. Som. Archaeological Soc. vol. xxxviii. p. 204.Google Scholar

page 97 note 6 Q.J.G.S. vol. xlvi. pp. 80–82.Google Scholar

page 97 note 7 SeeGeikie, , Text Book of Geology, pp. 241–242.Google Scholar

page 99 note 1 Note. Withdrawn, GEOL. MAG. 1892, p. 291.Google Scholar

page 100 note 1 See Characteristics of Volcanoes, Dana, J. D., p. 8.Google Scholar

page 100 note 2 Report Brit. Assoc. 1890, p. 815.Google Scholar

page 100 note 3 Q.J.G.S. vol. xlix. p. 397.Google Scholar

page 100 note 4 Loc. eit. p 397Google Scholar

page 101 note 1 Proc. Somerset Archaeological Soc. vol. xxxviii. p. 217.Google Scholar

page 101 note 2 Loc. cit. p 208.Google Scholar

page 101 note 3 See ante, p. 99.

page 101 note 4 Q.J.G.S. vol. xxxi, p. 517.Google Scholar

page 101 note 5 Q.J.G.S. vol. xlix, p. 422.Google Scholar

page 101 note 6 See ante, p. 98.

page 101 note 7 Report Brit. Assoc. 1889, p. 570.Google Scholar

page 102 note 1 SeeTrans. Devon. Assoc. vol. xxi. p. 261, plate, fig.3.Google Scholar

page 105 note 1 Report on the Geology of Cornwall, Devon, etc., p. 378.Google Scholar

page 105 note 2 Lnc. cit. p. 387.

page 105 note 3 Mr. J. B.Hannay has kindly informed me that he has dissolved quartz in superheated steam and produced transparent quartz crystals thereby.Google Scholar

page 105 note 4 Phil. Mag. 1873 (2), p. 32.Google Scholar

page 105 note 5 Loc. cit. p. 45.

page 106 note 1 SeeWorth, Trans. Dev. Assoc. vol.xix, p. 494.Google Scholar

page 106 note 2 Rep. Brit. Assoc. 1880, p.Google Scholar