The Geology of the Isle of Man
by G W Lamplugh
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from ... Show synopsis This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1903 Excerpt: ...the field, in small exposures, the dykes of this kind were very difficult to distinguish from the hard bands of fine-grained greywacke which sometimes occur isolated among the striped slates intermediate between the Barnile Slates and tbe grits of the Manx Series.., A large number of slides were therefore cut and examined to aid in tie mapping of these rocks; the five following examples will show their general characters': --TE. 1945. Dyke at landing stage in ianer harbour. Port St. Mary. lightgrey fine-grained diabase. Micro. A very fine-grained rock in which twinned needles of felspar are embedded in a fine ground-mass of felspar and chlorite; pyrites is present, and carbonates, probably of lime. Traces of flow-structure in direction of phenocrysts. Ferromagnesian minerals not observable. A fine aggregate of white mica. E. 1951. 1 ft. dyke, apparently intruded into a larger greenstone dyke 8--10 ft. thick. Cliff 122 yards s. of Viet Aldrick, s. of lort Erin. Greenish-grey highly schistose rock. Micro. Fine-grained ground-mass of felspar and chlorite, embedding small phenocrysts of felspar, not quite so much elongated as in case of 1945 though the rock is clearly of the same type. There are some traces of flow-structure and also shearing. Some rather large slivers of chlorite occur, and idiomorphic dolomite crystals are very abundant. E. 1962 20 ft. band: Cliff at Fhewtal, Niarbyl Bay. Medium-grained grey rock; decomposed diabase. Micro. Shows igneous structure; possibly was porphyrihe, little or no shearing perceptible. A confused aggregate ot quartz, calcite, chlorite, and more sericite than usual; linMite; a few small felspars. E. 2099. Boss or dyke: Coast at end of Gob y Deigan, N, of Peel. Decomposed diabase. Micro. Larger felspars altered to masses of..