Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/59

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49
Dr. Berger on the Isle of Man.

fracture is vitreous, but sometimes displays a sort of lamellar texture. The crystallized garnets are much less fusible than the basis or massive garnet: the latter passes into a brownish bead. There are besides in one of the specimens some nodules of radiated zeolite or mesotype. In another the mass of garnet is blended with white felspar.

At B. Wodden I noticed a large block of granular quartz with garnets? and hornblende. The rock has a greenish-grey colour. The fracture in the small is granular scaly. Another rock, related to the preceding, is amongst the Druidical stones of Kirk Ballaugh.

(b). Transition-rocks not in Situ.

Greywacke.

Between Ramsay and Aire-Point I saw in some heaps of stones a number of pieces and blocks of greywacke, passing from large grained into a small grained texture. The basis is greyish, the imbedded fragments are mostly nodules of white quartz with scraps of a dull and black sort of slate, fusible into a whitish enamel, and abraded plates or broad spangles of mica. The cavities that receive the nodules of quartz when freed from them, appear smooth and even. The pieces of slate turn sometimes clayey, micaceous, and of a brown ferruginous colour.

(c) Flœtz-Rocks.

Limestone.

I shall merely speak here of some water-worn limestone pebbles found in great plenty from Kirk-michael to Jurby point, though no solid strata of this kind can be seen in situ. They are picked

Vol. II.G