Archaeological Geology
Over the last 10 years the Archaeological Geology Division of the Geological Society of America has provided a forum for geologists dedicated to the elucidation of humanity’s past.
During the division symposium held at the October GSA meeting in Phoenix, Ariz., the latest discoveries and hypotheses about our earliest ancestors were discussed by Donald C. Johnson (Institute of Human Origins, Berkeley, Calif.), Tim D. White (University of California, Berkeley), and J.W. K. Harris, Larry F. Boyer, and R.V. Bellomo (University of Wisconsin-Milwaukee). Among new discoveries is a partial skeleton of an adult hominid from Olduvai George (about 1.8 million years old) with similarities to both Homo Habilis and some early Australopithecine hominids.
Harris and colleagues suggest that emergence of Homo erectus, about 1.5 million years ago, may indicate selection for large body size associated with changes in habitat, mobility, and use of fire. Russell L. Ciochaong (University of Iowa) places the age of the Asian Homo erectus at no more than 1 million years old, but notes strong morphological continuity among Asian specimens. Fred H. Smith (University of Tennessee-Knoxville) contends that modern humans have greater ancestry outside Europe, and that the origin of modern Europeans is peripheral to initial emergence of modern human anatomy. According to Henry P. Schwarcz (McMaster University), recent advances indicating modern humans and their immediate ancestors from 40,000 to 1 million years ago include uranium series using alpha-spectrometry, electron spin resonance and thermolunminescene.
For older periods, advances in the 40Ar/39Ar laser-fusion and external detector fission-track methods and in K/Ar dating were reported by Robert C. Walter (INSTAAR, Boulder, Colo).
A recent development in geochronology is the advent of high-precision calibration. The emergence of modern humans, Homo sapiens sapiens, has traditionally been dated at about 45,000 to 35,000 years ago. Uranium-series dating of a Mousterian site, predating modern humans in Catalonia, Spain, yielded ages ranging from 60,000 to 39,000 years old, according to James L. Bischoff (U.S. Geological Survey, Menlo Park, Calif). The transition to Homo sapiens sapiens, suggests William Farrand (University of Michigan), was related to climatic changes. According to Tjeerd H. van Andel (University of Cambridge, England), technological advances, social complexity, and changing sea level by the end of the Pleistocene were among factors that contributed to a dependence on marine resources.
The next major event in human prehistory was the advent of agriculture and subsequent rise of civilization. Studies I conducted in Egypt reveal that both the rise and continuity of Egyptian civilization depended on a dynamic interaction between people and changing Nile floods.
Archaeologist Juris Zarins (Southwest Missouri State University) claims he has located the Garden of Eden. Landsat imagery reveals 4 biblical rivers at the head of the Gulf. By 4000 B.C. the rising sea level drowned Eden. William Melson and Gus van Beek (National Museum of Natural History, Washington, D.C.) have described a group of pumices dating from the first millennium B.C. in sites east of Gaza in Israel.
Among other investigations in that region, Frank L. Koucky (College of Wooster) has determined that the King’s Highway route was not passable in winter and spring, and that travel was diverted to cross the headwaters near the late Roman/early Byzantine fortress of Leijun. Reuben S. Bullard (University of Cincinnati) is working on the paleoenvironments of Abila in northern Jordan, as well as on the geoarchaeology of Cyprus.
In Greece, John C. Kraft (University of Delaware) and coworkers reconstructed the shoreline at Thermophylae. Their results indicate that historical accounts of the battle there between the Persians and Spartans are accurate. Geological/archaeological investigations of southern Argolid by van Andel and C.N. Runnels (Stanford) appeared in Beyond the Acropolis (Stanford University Press).
Van Andel and Lisa Well (Stanford) completed fieldwork on coastal processes and civilization in Peru north of Lima. Observations of the 1983 El Niņo permitted identification of past major El Niņos of the last 6,000 to 8,000 years.
Paleoenvironments were the subject of numerous sedimentological, faunal, and palynological studies in 1987. Larry D. Agenbroad and Jim I. Mead (Northern Arizona University) studied alluvial sediments, dry cave deposits, and pack-rat midden U.S. arid Southwest. A study of paleolakes in eastern Utah by Donald Currey (University of Utah) revealed the impact of lake hydrography on human settlement. Vance T. Holliday (University of Wisconsin, Madison), in a study of Quaternary eolian sediment, found 10,000-year-old Plainview projectile points on the uplands that flank the Lubbok Lake Site, Texas.
Late Paleoindian artifacts dating from 10,240 to 9,010 years ago have been recovered by Thomas Jorstad (Gilbert/Commonwealth Inc., Jackson Miss.), who is investigating the interaction between floodplain development and archaeological occupations of the Ohio River Valley near Cincinnati. In Wyoming, the lowering of Jackson Lake exposed Clovis sites associated with paleobeaches. Obsidian-hydration dating of those beaches, and other geoarchaeological investigations, are being done by Ken L. Pierce (U.S. Geological Survey, Denver). James D. Hume (Tufts University) reconstructed the paleogeographic setting of the Eddy Site in New England as the floodplain of a meandering river.
Robert M. Thorson (University of Connecticut) is investigating the Bolton Spring Site, Alaska..
Pollen from Zuni, N.M., according to Stephen A. Hall (University of Texas, Austin) is helping to explain that paleoenvironmental changes that may have attracted immigrants from Chaco Canyon and the Anasazi pueblo area during the 14th century. In Oklahoma, the first finding of Zea mays of Pre-European age was made by J.R. Wilson (University of Oklahoma). Pollen analysis by Herbert E. Wright Jr. (University of Minnesota, Minneapolis) is contributing to paleoecological constructions in the central Peruvian Andes, western Ireland (Lough Gur Neolithic site), and souther Germany (Kelheim iron-age site).
Extensive taphonomic and zooarchaeological investigations by Holmes A. Semken (University of Iowa) now indicate that rodents and insectivores associated with archaeological sites are useful in interpreting paleoclimate.
Paleoenvironmental and stratigraphic data were obtained from paleopedological studies at Paleoindian sites in the Pine Bluffs area, Wyoming, by Richard G. Reider (University of Wyoming), and from the Calico site in California by Roy J. Shlemon (Newport Beach, Calif.).
Alison E. Rautman (University of Michigan) has completed a perographic study of ceramics from the medieval city of Vijayanagara in South India. She identified 4 compositional groups associated with spatially segregated social groups. Pottery from Ban Chiang, Thailand, was examined by William W. Vernon (Dickinson College) using xeroradiography, thermal expansion, and petrography, who concluded that the pots were made by 2 techniques: coil-and-slab and lump-and-slab.
A non-destructive X-ray fluorescence method was developed by Thomas Latham (Cornell) and Kenneth Verosub (University of California, Davis) to determine the provenance of basaltic artifacts.
Archaeological geology is also making a
contribution to the history of mining. James C. Dawson (State
University of New York, Plattburgh) is studying archaeological
remains of 19th-century iron mining in the Adirondack region. The
geoarchaeology of gold mining in Mammoth lakes is being
investigated by J. Gary Caldwell (Mount San Jacinto College).
Samuel T. Pees (meadville, Pa.), who is studying the archaeology
of early oil exploration, is trying to interest archaeologists
and geologists in the prehistoric mining of oils. There are 2,000
to 3,000 oil pits near Titusville, Pa.
This wall painting of Queen Nefertari, wife
of 13th-century B.C. Egyptian
ruler RamesII, is among those Getty Conservation Institute and
the
Egyptian Antiques Organization are trying to preserve in
Nefertari's tomb
through geoarchaeological studies. Buckling and disintegration of
plaster
layers caused by salt crystallization are among the most serious
problems
facing restorers. (Photo courtesy of Farouk El-Baz, Boston
University)
Geologists in 1987 used various geophysical methods to resolve archaeological problems. A seismic survey along the Penobscot River in Bangor, Maine, was done by Thomas K. Weddle (Maine Geological Survey) to clarify the stratigraphy of archaeological sites. Magnetic prospecting for hearths in the Genesee Valley has been attempted by William J. Brennan (SUNY, Geneseo). In California it appears that grooves in some ‘petroglyph’ sites were actually formed during tectonic emplacement of rocks, according to Robert K. Mark (USGS, Menlo Park, Calif.). George R. Rapp Jr. (University of Minnesota, Duluth) suggests that geological phenomena other than earthquakes can explain ‘destruction’ layers in archaeological sites.
Our understanding of geological processes was enhanced by several geoarchaeological investigations in 1987. For example, a construction by Roger T. Saucier (U.S. Army, Vicksburg, Miss.) Of the chronology of the Mississippi River is heavily dependent on archaeological evidence. Robert J. Dineen (New York Geological Survey) is examining archaeological data to estimate the recurrence interval of floods in the Susquehanna River Basin. Long-term studies of the basin reveal 3 terraces from 10,000 to 1,500 years old.
Archaeological data are also providing a method for interpreting changing hydrological conditions in the coastal plain of the southeast U.S. Mark Brooks, Peter Stone, and Donald Colquhoun (University of South Carolina) concluded from a study of lateral and vertical disruption of occupation sites that the curve of fluvial sedimentation for the Savannah river valley mimics the South Carolina sea-level curve during the Holocene, with reduced accumulation father upstream.
Archaeological geology made the news in the June 12 issue of Science. Farouk El-Baz (Boston University) is leading a team of geophysicists in search of ancient Egyptian air trapped with a funerary boat in a chamber near the base of the Great Pyramid of Khufu. Space technology, specially designed air-lock drills, and a heat-free fiber-optic light source will be used to sample the air and obtain photographs of the hidden boat. Examination for chlorogluorocarbons, the ozone destroying chemicals, will show whether CFCs are from natural or human sources.
Daniel J. Stanley and V. Coutellier (Smithsonian Institution, Washington, D.C.) Have just completed a study of the late Quaternary stratigraphy and paleogeography of the eastern Nile Delta. A progradation of the delta in the last 5,000 years implies that Tanis was once near the coast.
Stanley also has discovered Upper Minoan ash in the eastern Nile Delta, perhaps from the eruption that might have caused the ‘plague of darkness’ of the Exodus. The 1645 B.C. (Minoan) Plinean eruption is under study by Floyd W. McCoy Jr. (Lamont-Doherty Geological Observatory). Charles J. Vitaliano (Indiana University, Bloomington) has identified Y-5 ask in deep-sea cores from the Aegean Sea in 2 new localities beyond the known perimeter of the ash.
Geological processes that contribute to the deposition or transformation of archaeological remains are now a subject of great interest. Michael B. Schiffer (University of Arizona) published Formation processes of the archaeological record (University of New Mexico Press), a comprehensive review with examples of applications to the chronology of the Hohokam and the archaeology of Broken K. Pueblo. Natural formation processes and the archaeological record (BAR International Series, Oxford, England), edited by D.T. Nash and M.D. Petraglia (University of New Mexico) has other applications.
In a monograph by Arlene Miller Rosen titled Cities of clay (University of Chicago Press), geomorphological, sedimentological, and stratigraphic studies were combined with archaeological data to provide a detailed amount of the formation of Near East tells (archaeological mounds).
Vistas for future research in archaeological geology are exhilarating, as may be judged from the review by G. Rapp Jr. in Annual review of earth and planetary science (v. 15, p. 97-113). Geoarchaeology in the year 1987 made significant contributions to the geological history of humankind. From discovery and dating of early hominids to archaeology of early oil exploration, the work continues.