Notes on mineralogy. No. II. On the chemical composition of the granites of the south-east of Ireland / by Samuel Haughton.

  • Haughton, Samuel.
Date:
[1855]
Catalogue details

Licence: Public Domain Mark

Credit: Notes on mineralogy. No. II. On the chemical composition of the granites of the south-east of Ireland / by Samuel Haughton. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    grained granite from Kiltealy, on the Wexford slope of lilackstairs. No. 8. Bulhjleigh.—%\)cc\^c gravity, 2-6.27. A fine-gi-ained granite taken from near Poulinoiinty Bridge, at the south- west extremity of the granite chain. Calculating the atomic quotients from Table L, we construct the following Table, contaming the values of a, b, c, and of Q, F, M, calculated from equations (1). Table II.—Atoms of Granitic Minerals. Atoms of silcx = «. Atoms of peroxi<le^s = /). Atoms of l^rotoxides = c. Atoms of quartz. Atoms of felspar. Atoms of mica. 0-280 0353 1-587 0296 0274 0-513 0252 0-022 1-528 0-.'}52 0-287 0-1-45 0-222 0 065 liruiiskerrv 1 0282 0-225 0-770 0 168 0 057 1 .lU) 0-.S17 0-283 0-442 0-249 0034 Killballviiu^'h 1 ■3'J2 0 321 0-232 0-753 0143 0089 1-587 0-322 0-23:) 0-714 0156 0-083 liallylcigh 1 5!)3 0-271 0-257 o-57y 0243 0014 Calculating, by the method already described, the per-ccntages of quartz, felspar and mica, contained in the different granites, we tind the following: — Table III.—Per-centages. Locality'. Quartz. Kel.^par. Mica. Dalkey 6-71 23-60 6!)-66 Tlirce Rock 20-47 59-68 19-82 35-42 45-83 17 38 20-;i3 68-97 10-37 34-64 38-37 2714 Blackstairs 32-84 4119 25-31 liallvleigh 26-63 67-45 4-27 From the foregoing calculations, it follows, that, with the ex- ception of the Dalkey granite, the granites of the main chain examined might be represented by combinations of quartz, fel- s])ar and mica, in which the (inartz is the most regular mineral, considered witli reference to its per-centagc. The following Table contains analyses of granites belonging to the second grou]), and supposed to be newer than the others.