Desertification in southern Europe
The threat of desertification appears in southern Europe when periods of prolonged drought are followed by torrential rains falling on steep, unstable terrain. The plant cover of many regions has been degraded since very ancient times. Some are now recovering as a result of emigration and reduce pressure on the land. Tourist and commercial agricultural developments threaten habitat values and water supplies, especially in certain coastal areas. Relatively abundant archeological and literary resources offer excellent opportunities for tracing land use histories and throwing more light on the nature and direction of environmental change. Such longitudinal studies should be integrated with remote sensing and nested sampling on the ground of current landscape conditions and monitoring of current processes.
Observations on the Historical Ecology of Boeotia
This study was part of the work of the Cambridge-Bradford expedition to Boeotia. It gathers information on wild vegetation as part of the environment of, and resources available to, human activities. It is concerned with vegetation, with the structure, maintenance, and history of plant communities, rather than with flora, with individual plant species as such. The survey extends beyond the area of the archaeological survey (Mavromati), a highly cultivated area; in order to search for plant communities of a more nearly natural kind, this botanical study includes a much wider area covering almost the whole of the modern Boeotia (and beyond) from Mt. Parnassos to Chalkis. The land, geology, and soils are described as the essential context for the vegetation. Factors affecting modern vegetation are analysed, and the historical and archaeological evidence is discussed. It is concluded that, contrary to the general assumption, prehistoric Boeotia was a semi-arid land, both in classical and late Turkish times. The main features were very much as they are now, but this was not necessarily constant.
Sedimentation in Permian Castile Sea
The Permian Castile formation is a favorable starting point for a study of precipitated marine sediments because of its relatively simple stratigraphy. It is 1,300 to 2,000 feet thick and consists principally of "banded" or laminated anhydrite, but it contains some salt and other materials. It was deposited within the deep steep-walled Delaware Basin of western Texas and southeastern New Mexico. Throughout Castile time communication with the open sea was maintained through a restricted channel near the southwest corner of the basin. Paucity of detrital material indicates that the deposit consists almost exclusively of marine evaporites. It is suggested that the water within the basin consisted of a body of brine lying below average wave base and a less dense surface layer lying above average wave base. Some of the dense brine continuously returned to the open sea; otherwise the volume of halite deposited would have been about 30 times as great as the volume of anhydrite instead of somewhat less than the volume of anhydrite. The barrier must therefore have been incomplete. Either the top lay partly below wave base or the barrier was permeable. This theory of reflux is presented as a modification of Ochsenius' bar theory. The calcium sulphate presumably was deposited as anhydrite rather than as gypsum because of the salinity of the brine. The banding is ascribed to seasonal variation in temperature. The average net rate of evaporation in Castile time is calculated as 114 inches a year.