So contentious have been the arguments about possible pre-Clovis man in the Americas that it appeared inevitable that acceptance would only occur if such a site contained skeletons or artifacts of unambiguous human origin, was well dated both by stratigraphic context and by unequivocal numeric dating techniques, and was excavated by highly regarded traditional archaeologists. Such a site has finally been found, not in North America geographically close to a presumed Beringia migration route, but at Monte Verde in Chile (Dillehay, 1966; Meltzer, 1997).
By 1997, some 80 earth-science specialists visited Monte Verde, many participated in the excavations, and still others collected samples and conducted laboratory analyses. The results are remarkable: now documented are 70 species of plants collected by Early Man, the remnants of mastodon meat, the remains of wooden canoes, mortars, and hundreds of stone artifacts including projectile points and cutting and scraping tools. Additionally, some 30 radiocarbon dates were obtained from abundant charcoal, wood and ivory found within the artifact-bearing strata. These dates indicate that Monte Verde was occupied about 12.5 ka ago, a full thousand years before Clovis (Meltzer, 1997). Now, perhaps, even the most skeptic, pre-Clovis non-believers may well have been converted.
But questions still remain: How long did it take for man to migrate from Beringia to Monte Verde? Did this occur thousands of years before 12.5 ka ago? If so, could such migration(s) have taken place during times of maximum ice extent, even though the environment would have been extremely inhospitable. Or did such migrations really take place before the last major glaciation, perhaps before about 20 ka, or even 35 ka ago? Prior to Monte Verde, the conventional answer would be "where is the evidence for such Early Man?" In reality, such evidence may well have been seen previously, but largely dismissed owing to the traditional dogma of "no pre-Clovis sites in the Americas." Accordingly, with Monte Verde now reasonably accepted, it seems likely that traditional archaeologists will soon "find" other pre-Clovis sites in the New World.
(There is another site near Monte Verde that is believed to date to 35-50,000 years old)
Though Calico and many other previously inferred pre-Clovis sites may ultimately be accepted as "legitimate," the real challenge is to predict the general location and to actively explore other such sites. But where? Logically, they should occur on surfaces about 200 ka old. But such surfaces are rare owing to rapid fluvial dissection or to later covering by sediments. Indeed, most of the world's geomorphic surfaces are no older than Holocene (~10.5 ka). There are exceptions, however. For example, some remnant, high-level alluvial fans in the Mojave Desert are more than about 100 ka old, recognized by their tightly packed desert pavement, their dark- colored patina (desert varnish), and their strongly developed surface soils (relict paleosols; Shlemon, 1978). But such desert surfaces are, and were, inherently inhospitable for continued human occupance. Therefore, few high concentrations of undisturbed artifacts are likely to be found.
In contrast, the most promising, unequivocal Early Man targets are buried, often under many meters of sediments. Only a fraction of the ancient surfaces (buried paleosols) are ever seen, usually in fortuitous road or mining cuts. The most favorable Early Man targets are old shorelines that mark the junction of diverse environments, and thus are particularly susceptible to artifact concentration and preservation (Budinger, 1992).
Though rare, such paleo-environments may also be exposed in natural cuts. Ironically, one of the best Early Man "targets" are natural exposures that occur very near the Calico site. Indeed, the full acceptance of Calico may not come from collecting more on-site artifacts, but from systematic observation and possible excavations in the nearby Manix Lake beds (Shlemon and Budinger, 1990). The stratigraphy of the well exposed Manix beds is remarkable, for these beds range in age from about 20 ka to 290 ka, recording climatic and sedimentation change in this part of California for much of middle and late Quaternary time; they interfinger distal fan sediments that emanated from the Calico Mountains and other nearby "quarry sites;" they bear several datable ash beds, one of which is an estimated 185 ka, tantalizing close to the 200 ka age for the Calico artifact-bearing beds; and they contain abundant vertebrate fossils. In sum, the Manix Lake beds are a classic Early Man target. They may indeed be the place for a new breed of archaeologists and their geoscience colleagues to explore unabashedly for pre-Clovis sites. Such endeavors are no longer far fetched, particularly in light of the recent Monte Verde and Diring discoveries. Accordingly, it appears that we will soon see a "quiet revolution" in New World archaeology whereby mainstream archaeologists reinterpret their data and thus "document" pre-Clovis sites. If so, New World archaeology will take a giant step forward, perhaps analogous to the now-famous 1970's "plate tectonic revolution" in geology.
Wow, just found this from your link. That’s fascinating and if the 200K dating holds it certainly upends a lot of other ‘theories’.