Loess and Palaeolithic Chronology

Abstract

In the present paper it is intended to summarize the reasons why loess sections must be regarded as important for the chronology of the Palaeolithic, and to discuss an important problem to which loess sections have contributed in recent years, that of the chronological relations between the Mousterioid and the Upper Palaeolithic industries. This problem has received particular attention in the Geochronological Laboratory of the Institute since its formation by Sir Robert Mond in 1936. Several hundred analyses have been made, some of which will be published shortly in these Proceedings, from sites ranging from the Iberian Peninsula, Italy, Hungary and Poland through France and Germany to southern England, as well as from India, Africa and northern Arabia. During the later stages, the work was supported by the Central Research Fund of London University, whose help is recorded with gratitude.Loess analysis comprises the study of grain size by mechanical analysis, determination of calcium carbonate and organic matter, the study of its porosity and texture and of the shape and quality of its grains. Two years were spent in the laboratory on the testing and improvement of various methods in use, and especially of mechanical analysis, so that the laboriousness of the work has been much reduced and results can be obtained more quickly.The aeolian origin of loess is no longer disputed. Loess is essentially rock dust blown about and deposited from an air current. This necessitates a dry environment due either to aridity or to frost, and scarcity of vegetation. Loess dust is thus picked up on bare surfaces and deposited mainly in the steppe, where low and sparse vegetation acts like a comb, slowing down the air current and compelling it to deposit its load. Any dust that reaches the humid forest zone is incorporated in the soil that is forming there, and it thus disappears.