Solving archaeological problems using techniques of soil magnetism

Archaeological investigations into the processes and factors controlling the magnetic enhancement of soils were initiated in the 1960s in conjunction with the application of magnetic prospection surveys. After a highly productive period of research, archaeological interest in soil magnetism experienced a downswing, which has just recently been reversed. Continuing research within the fields of rock magnetism and environmental magnetism has refined our understanding of the processes and products of magnetic enhancement and demonstrated the broad applicability of soil magnetic analyses. Using this information, together with recent archaeological studies, we update archaeologists on the variety of soil magnetic techniques and how they can be utilized to define, detail, and understand archaeological sites, features, and environments. A case study at the Cahokia Mounds Site in southwestern Illinois illustrates how soil magnetic techniques can be interfaced with other methods to understand archaeological landscapes and landscape change. © 1998 John Wiley & Sons, Inc.     

Geophysical identification of unmarked historic graves

Down‐hole magnetic susceptibility techniques were explored as a means of improving near‐surface geophysical surveys in historic grave detection. These techniques were used to document distinctive magnetic characteristics of grave shafts at three historic cemeteries first surveyed using various near‐surface geophysical methods. Tests revealed a low magnetic susceptibility signature that soil magnetic studies indicated was largely related to differential soil compaction associated with the excavation and refilling of grave shafts. Most apparent at depths beyond those reached by soil penetrometers, this magnetic signature offers a way to assess anomalies identified by near‐surface techniques that potentially represent graves. At one cemetery, magnetic studies of the interments themselves suggested spatially patterned, magnetically enhanced zones that might also aid in burial identification in certain contexts. While down‐hole techniques will not be foolproof, they do provide another geophysical tool that can be used to improve grave detection. © 2010 Wiley Periodicals, Inc.     

贡嘎山海洋性冰川发育条件及分布特征

贡嘎山５０００ｍ以上山体面积占全区总面积的六分之一，这样高大的山体为冰川发育提供了有利的地势条件和宽阔的积累区。同时，据观测推算东坡冰川积累区的年降水量可达３０００ｍｍ，雪线处的年平均气温在－４．１—－５℃；西坡冰川积累区的年降水量达１８００ｍｍ为本区冰川发育提供了丰富的冰雪物质条件和必要的低温。冰川形态类型基本齐全，冰川分布比较集中，但东西坡冰川在规模上有明显差异，东坡冰川条数较西坡少，但冰川规     

Geophysical indicators of culturally emplaced soils and sediments

Archaeologists dealing with earthen forms must distinguish those constructed by humans from those with a natural origin. Geophysical techniques can help identify culturally loaded soils and sediments. We suggest that intrinsic changes in geophysical properties, due to cultural loading, can serve as fingerprints in determining whether a mound or other earthen form is natural or culturally constructed. Culturally emplaced soils might be identified through anomalous values in geophysical properties or through unusual spatial or stratigraphic complexity. The identification of this “lumpiness” in geophysical properties may involve geophysical techniques quite different from those employed in traditional archaeogeophysical surveys. Experiments at three prehistoric mound sites (the Cahokia Mounds State Historic Site, Effigy Mounds National Monument, and the Hopeton Earthwork) illustrate a number of these techniques including studies of the anisotropy (directionality) of geophysical properties, seismic Rayleigh (surface) waves, and magnetic susceptibility. © 2002 Wiley Periodicals, Inc.     

A magnetic susceptibility logger for archaeological application

Investigations of magnetic susceptibility have been used to (1) define sites, activity areas, features, buried soils, and cultural layers, (2) build and correlate stratigraphic sequences, and (3) understand site‐formation and postdepositional processes. Archaeologists are limited in these endeavors, however, by the instruments available for field studies of susceptibility. A prototype instrument developed for archaeological application logs volume magnetic susceptibility down a small‐diameter (ca. 2.2 cm) core‐hole made with a push‐tube corer. Measurements can be made rapidly, approximately 10 times faster than collecting samples either by coring or from an exposed section, to depths of 1.6 m below the surface. The prototype logger was field‐tested on a mid‐Holocene stratigraphic section in southeastern North Dakota where it clearly distinguished various soils and sediments, including a buried occupation layer. © 2001 John Wiley & Sons, Inc.