OCR Text |
Show Donald K. Grayson Burke Memorial Museum, Box 353010 University of Washington Seattle, WA 98915 GREAT BASIN MAMMALS AND LATE QUATERNARY MOISTURE HISTORY To paleocologists and archaeologists, one of the most enduring legacies of the volume whose anniversary we are now celebrating was provided by Ernst Antev's short contribution. Here, in an article that was to become widely- cited and even more widely- read, Antevs recounted his tripartite Neothermal climatic sequence and demonstrated apparent correlations between that sequence and the general nature of the arid western archaeological record. There were several reasons for the influence that this article, in conjunction with others that Antevs had written and was soon to write, had on paleoecologists and archaeologists. From an archaeological perspective, Antevs' " geo- climatic dating" provided a means of assigning ages to prehistoric sites that could be dated in no other way. In addition, Antevs' climatic scheme was, in fact, generally correct, as was his argument concerning the interrelationships between climatic change and human population density in the Great Basin. Less widely realized, however, is the fact that Antevs soon changed his interpretation of the climatic nature of the basal unit in his Neothermal sequence. In 1948, and in a series of other publications extending into the early 1950s, Antevs characterized this period of time as both moist and warm, with temperatures at first like those of today, but soon becoming warmer than modern. By the mid- 1950s, however, Antevs had changed his assessment of this period of time, now arguing that while it was moister than modern, it was also cooler, with temperatures slowly rising as the Altithermal was approached. There is now little question that Antev's general characterization of that period of time we now call the Early Holocene was correct for much of the Great Basin. All seem to agree that the Early Holocene was, in fact, moister than what came later. He must also have been correct concerning the general nature of Early Holocene temperatures, though whether it was Antevs I ( warmer than modern) or Antevs II ( cooler than modern) that got it right is not at all clear. Climatic models suggest that the Early Holocene of the Great Basin was both moister and warmer than anything that has come since. Indeed, some of those models suggest that the Early Holocene was even warmer than the Middle Holocene. Relevant data provided by vertebrate paleontology, particularly for small mammals, has long been available but has largely overlooked in making these assessments. This is unfortunate, both because small mammal sequences provide sensitive, if not always transparent, information on moisture and temperature histories in the Great Basin, and because these data pose significant challenges to current model- based paleoclimatic reconstructions. |