Generalizations respecting the Erratic Tertiaries or Northern Drift, founded on the Mapping of the Superficial Deposits of a large portion of Norfolk

Abstract

In exhibiting to the Society a map of the variations of soil over a considerable portion of Norfolk, by which the dependence of those variations on contours is shown, I avail myself of the opportunity to communicate a brief outline of the conclusions to which I have been led, respecting the erratic phaenomena, by a very minute examination of a district where they are well exhibited, and where their place in the geological scale of time is well defined. These variations were laid down by me, during parts of the years 1844, 1845, and 1846, on the Ordnance Map—a work which was undertaken as the basis of a paper on the Distribution of Soils, written for the Journal of the Royal Agricultural Society*. In that paper I confined myself, as much as possible, to subjects having a practical agricultural interest; reserving others of a purely geological character for publication in some scientific journal. They were embodied, at the request of Sir Henry De la Beche, in a memoir which I prepared in the beginning of 1847, for the Memoirs of the Geological Survey of the United Kingdom; in which the erratic tertiaries of Norfolk were compared with a small portion of those of South Wales, which I had mapped, during part of the preceding summer, for the Government Geological Survey. As various unexpected circumstances have delayed the publication of that paper, and as I understand there is no prospect of its appearing at present, I am desirous of now placing