This paper presents, in detail, facts about original structures of modern beaches, bars, and dunes, and stresses especially their stratification. It attempts also to formulate criteria for recognition of ancient bars, dunes, and stratified beaches that lack organic remains, which might reveal the origin of the deposits.
For more than a century, the subject has been dealt with by numerous writers but little order has been brought out of the confusion. It is hoped that by very detailed studies of the formation of modern beaches, bars, and dunes a better means of interpreting these deposits may be worked out.
The writer spent nearly a year along the coast of California, between San Francisco and San Diego, examining various deposits, some of which are modern beaches, and others contain fossils indicative of ancient beaches. In addition, beaches and bars of lakes, as well as eolian deposits, were examined . . .