TO THE

Memory of his Father

DR. SAMUEL P. WOODWARD, A.L.S. F.G.S.

AUTHOR OF 'A MANUAL OF THE MOLLUSCA,'

This Book is Dedicated :

FOR TO HIS EARLY TEACHINGS AND INFLUENCE

THE WRITER IS LARGELY INDEBTED.

151177

PREFACE.

THE publication of a book intended to give an account of the Geology of England and Wales requires a few prefatory remarks from the writer who has to deal with so comprehensive a subject.

When, in the year 1822, the Reverend W. D. Conybeare and William Phillips issued their 'Outlines of the Geology of England and Wales,' the science had but commenced that rapid growth which has characterized it during the past fifty years. The philosophic teachings of Hutton, Playfair, and William Smith had as yet to be developed; and it was only after the true principles of Geology had been illustrated in the early writings of Scrope, and elaborated by De la Beche and Lyell, that its place among the Inductive Sciences was fully established.

No work has proved more useful to the field-geologist than that of Conybeare and Phillips; and, on account of its being essentially a record of facts, it is much appreciated and valued at the present day. But the labours of half a century have materially altered our views of the nomenclature and classification of the rocks, and increased to a very large extent our knowledge of their life-history. The work of the pioneers has been followed up by an ever-increasing band of geologists; while the labours of the Geological Survey, and those of the Palæontographical Society, have tended very greatly to the development of the science, in the eluci

dation of the minute structure of our country, and in the determination of the varied forms of life which have been entombed in the rocks.

As a natural consequence the progress of Geology is accompanied by increasing detail and subdivision, and a work based on the Geological theories prevalent fifty years ago is clearly unsuited to the requirements of the present day. This work has consequently been undertaken with the view of supplying an obvious want, and, bearing in mind the paramount importance of using the hammer and chisel, it is specially intended to furnish a guide for those who go out into the field to study. The descriptions of the different strata will probably be sufficient, with the help of a geological map, to enable anyone to identify them in the field, while the fossils enumerated have been selected as those most abundant and characteristic.

So far as possible, all the local names of rocks, many of them geographical ones, have been given; and it has also been my aim to include all Synonyms, it being frequently impossible to understand the various papers on isolated questions or localities without information relative to them. It is unfortunate that this necessity should exist, as these varieties of nomenclature are as confusing to the student as they are detrimental to the progress of Geology.

The enumeration of the various economic products of the rocks, with the indication of their geological age, will, it is hoped, be found a useful feature in the work.

The formation of our scenery-one indeed of the most interesting of geological topics-has been sketched briefly, and with the endeavour to avoid giving undue prominence to any particular theory.

The Igneous and Metamorphic rocks have been treated less fully than those of a Sedimentary character for the reason that their history and nomenclature require further illustration

and greater precision than they have at present received. Many of the names given to these rocks, solely from inspection in the field, have not borne the test of microscopic and chemical investigation; but of late years considerable attention has been given to the subject, and the harvest of knowledge to be expected is great. In the mean time the Tables included in this work, which have been very kindly furnished to me by Mr. F. Rutley for the purpose of showing the classification of these rocks, cannot fail to prove useful to the student.

It may be thought that the Fossils have received too little notice, and I would gladly have said more about them, could I have done so with justice. But I considered that the insertion of mere lists of names, unaccompanied by figures, would have been of little benefit to the student in the field; nor could full lists, and figures of even the characteristic fossils, have been given without doubling the size of the volume. Moreover, Mr. W. H. Baily has for some time been engaged upon a series of Figures of Characteristic British Fossils, with Descriptive Remarks;' and he has published the Paleozoic portion. May his task soon be completed! Mr. Lowry, too, has engraved and published an excellent Chart of British Fossils, and a stiil more useful one of British Tertiary Fossils.1 These will be found to answer most purposes of the student, who, as a rule, must be satisfied with determining the genus of any fossils he may collect, leaving the specific names to those whose special work lies in some department of Palæontology. Access, however, to the splendid Monographs published by the Palæontographical Society, or a comparison of his specimens with those exhibited in the cases of some Museum, will often enable the geologist to determine the species he has obtained.

1 A special Chart of Fossil Crustacea was prepared by Messrs. J. W. Salter and Henry Woodward.