. The Quarterly journal of the Geological Society of London. , PhotO. Btmrose, Derby. Pseud otachylyte of Par us (0. ). Quart. Journ. Geol. Soc. Vol. LXX1I, , Photo. Bemrose,Collo . Derby. PSEUDOTACHYLYTE OF PaRIJS (0. F. S ), ETC. part 3] THE PSEUDOTACHYLVTE OF PAItUS. 221 between fused material and mylonite ought to be did not appear to be such a gradation ; while, on the otherhand, there was abundant evidence that the material had possesseda sufficiently high temperature to fuse the minerals of the invadedrocks. The question then arose : why
. The Quarterly journal of the Geological Society of London. , PhotO. Btmrose, Derby. Pseud otachylyte of Par us (0. ). Quart. Journ. Geol. Soc. Vol. LXX1I, , Photo. Bemrose,Collo . Derby. PSEUDOTACHYLYTE OF PaRIJS (0. F. S ), ETC. part 3] THE PSEUDOTACHYLVTE OF PAItUS. 221 between fused material and mylonite ought to be did not appear to be such a gradation ; while, on the otherhand, there was abundant evidence that the material had possesseda sufficiently high temperature to fuse the minerals of the invadedrocks. The question then arose : why had the black rock crystal-lized so badly ? One explanation might lie in the assumption thatthe intrusion was feebly supplied with volatile fluxes; and such acondition would naturally arise if some deep-seated rock that hadpreviously crystallized and lost its fluxes, were again to be raisedto its melting-point—by severe crushing, or rise of the geotherms,or any other cause. The Author stated, in the abstract of his paper, that the compo-sition of the rock was practically that of a granodiorite, and that itmight correspond to an average of the granite^pes in which theveins
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Keywords: ., bookcentury1800, bookdecade1840, bookidquarte, booksubjectgeology
