The Hornblendic and other Schists of the Lizard District, with some additional Notes on the Serpentine

Abstract

I. Preliminary . In my paper on the serpentine and associated rocks of the Lizard district, I made a few remarks only on the hornblendic and other schists, as the investigation of that series was foreign to the purpose then in hand, and in the concluding paragraphs I incidentally mentionedm it as being “probably about Lower Devonian age.” Soon after the publication of that paper I began to pay special attention to the structure of metamorphic rocks of sedimentary origin, and before long to feel the gravest doubts as to the possibility of the great mass of schists associated with the Lizard serpentines being of the same age as the slaty and little-altered Cornish strata, which belong mainly, if not altogether, to the later Palaeozoic period. Each year's experience with the microscope and in other regions did but strengthen this conviction, which of late I have ventured to express frequently ; but it was not until last Easter vacation that I was enabled to revisit the Lizard. In about ten days of hard work I examined with considerable care the coast sections of “hornblende schists,” as indicated on Sir H. De la Beche's map, from the Lizard Head to Porthalla on the east, and to Polurrian Cove on the west. During the major part of this time I had the advantage of being accompanied by my friend and former colleague the Rev. E. Hill, Tutor of St. John's College, Cambridge, whose friendly aid I most gratefully acknowledge. A large series of

This publication has 0 references indexed in Scilit: