Knowledge of the factors affecting site selection for ancient man is continually being enhanced through the cooperation of archaeology with other scientific disciplines. This volume, the fourth of the Wadi a1 J u b a h archaeological project, is an excellent example of such enhancement. Its three-fold purpose is: 1) to establish for the archaeologist the geological evolution since Precambrian time of the Wadi alJubah area in the eastern part of the Yemen Arab Republic (Y.A.R.), and specifically of the al-Jididah basin, in which it appears that agriculture arose during the last third of Holocene time (ca 3300 years ago); 2) to stimulate interest in the complex processes represented in the Quaternary geologic and geomorphic environment and the little known resulting sedimentary deposits, so important in the agricultural development of the region; and 3) to present and preserve considerable chemical data on geological and archaeological materials collected and analyzed during the study.
In the introduction to the 14 part report Jeffrey A. Blakely, the project's Field Director, enumerates the questions posed by archaeologists, which led to the need for geologic and geomorphic expertise, the subject of the report.
In Part 1 Michael B. Toplyn discusses the excavation strategy of a burial cairn at al-Faraah and the interpretation of the findings. The pre-excavation preparation, the finds, the skeleton dating, sex, and age considerations are treated. In an appendix, the analysis of a brass fragment and of a glass bead found in the burial cairn are reported by John F. Merkle and Charles P. Swann, respectively.
Part 2 deals with an attempt to determine the method of origin of desert varnish on a cobble found in the stone burial mound. A new technique for cation-ratio determination by means of the scanning electron microscope is described by Charles D. Harrington. Harrington concludes, based upon similarity to rock varnishes from the southwestern United States, that the Y.A.R. desert varnish is composed mainly of manganese and iron oxides and formed in a sparsely vegetated area of little rain, similar to the climate that must have existed for the same time period in the Yucca Mountain area of the southwestern United States.
In part 3 Theodore Botinelli and David E. Detra report on the chemical and mineralogical composition of silts from a burial mound at al-Faraah as compared to similar sediments from elsewhere in the area. It appears that the burial mound samples in the <63 um range are similar in composition to samples of similar grain size range from elsewhere in the area. Eolian mixing, transport, and deposition are the most likely processes involved in the accumulation of the sediments. Sediments in the burial mound are slightly enriched in heavy mineral content, suggesting that the burial mound acted as a trap for the airborne silts.
In part 4 John R. Watterson, Michael R. Toplyn, and David Updegraff discuss the microbiology of the endospores associated with the silts from an ancient burial mound at al-Faraah, dated at 1370 2 70 yrs. (uncorrected). The evidence found by the study, undertaken to determine whether the entombed skeleton represents a primary human