Results of an Examination of the Crystalline Rocks of the Lizard District

Open Access
Publisher Website
Google Scholar
Abstract
I. I ntroductory . G eologists during the last decade have devoted much more attention to the rocks of the L i z a r d t h a n in previous years. At the same time the effects of pressure as an agent of metamorphism, especially in producing ibliation and simulating stratification, have become increasingly appreciated. Hence it is not surprising that the correctness of the view advocated by Prof. Bonuey in 1883, viz., that the crystalline schists of the Lizard were in the main of sedimentary origin, has been contested, some writers even going so far as to express doubts whether the relation of these masses to the serpentine, gabbro, and other rocks of igneous origin had been correctly understood. The results of work in other regions had raised suspicions in the author's own mind as to the trustworthiness of some of the data on which his inductions had been founded, and after spending several days in 1886 at the Lizard with Mr. Teall, who was more disposed than himself to regard pressure as a potent agent of metamorphism, he felt convinced that his earlier views would have to be modified, though to what extent could only be determined by further study of the district and by comparison with other regions. In 1889 a paper was read before this Society by Gen. M cMahon , in which the igneous origin of many of the foliated crystalline rocks was maintained, and an hypothesis put forward to explain, in certain cases, the banded arrangement of

This publication has 0 references indexed in Scilit: