The fluvial and geomorphic context of Indian Knoll,an Archaic shell midden in West‐Central Kentucky

Indian Knoll is the largest Archaic shell midden excavated by WPA archaeologists in Kentucky. Situated in a large alluvial valley, the site is not associated with a known river shoal as might be expected, making its fluvial and geomorphic setting of interest. Based on sediment cores and auger samples, undisturbed portions of the site remain despite extensive excavations. In undisturbed portions, a shell‐bearing layer is overlain by a shell‐free midden layer. Profiles of organic matter and calcium carbonate content for both layers are similar to those of other Green River shell middens. New radiocarbon determinations date the shell deposit at 5590–4530 cal yr B.P. Analysis of mussel species collected from the Indian Knoll indicates that shell fishing took place in a swiftly flowing, shallow to moderately deep setting of the main river channel. Overall, the prehistoric river setting adjacent to Indian Knoll was characterized by deeper water on average with variable but finer‐grained substrate compared to other Green River shell midden sites. © 2002 Wiley Periodicals, Inc.     

Holocene geoarchaeology of the Sixteen Mile Beach barrier dunes in the Western Cape, South Africa

Holocene evolution and human occupation of the Sixteen Mile Beach barrier dunes on the southwest coast of South Africa between Yzerfontein and Saldanha Bay are inferred from the radiocarbon ages of calcareous dune sand, limpet shell (Patella spp.) manuports and gull-dropped white mussel shells (Donax serra). A series of coast-parallel dunes have prograded seaward in response to an overall marine regression since the mid-Holocene with dated shell from relict foredunes indicating periods of shoreline progradation that correspond to drops in sea level at around 5900, 4500 and 2400 calibrated years before the present (cal yr B.P.). However, the active foredune, extensively covered by a layer of gull-dropped shell, has migrated 500 m inland by the recycling of eroded dune sand in response to an approximate 1 m sea level rise over the last 700 yr. Manuported limpet shells from relict blowouts on landward vegetated dunes indicate human occupation of coastal dune sites at 6200 and 6000 cal yr B.P. and help to fill the mid-Holocene gap in the regional archaeological record. Coastal midden shells associated with small hearth sites exposed in blowouts on the active foredune are contemporaneous (1600-500 cal yr B.P.) with large midden sites on the western margin of Langebaan Lagoon and suggest an increase in marine resource utilisation associated with the arrival of pastoralism in the Western Cape.     

Geoarchaeology of the Nehalem spit: Redistribution of beeswax galleon wreck debris by Cascadia earthquake and tsunami (∼A.D. 1700), Oregon,USA

A coincidence of the Beeswax galleon shipwreck (ca. A.D. 1650–1700) and the last Cascadia earthquake tsunami and coastal subsidence at ∼A.D. 1700 redistributed and buried wreck artifacts on the Nehalem Bay spit, Oregon, USA. Ground‐penetrating radar profiles (∼7 km total distance), sand auger probes, trenches, cutbank exposures (29 in number), and surface cobble counts (49 sites) were collected from the Nehalem spit (∼5 km² area). The field data demonstrate (1) the latest prehistoric integrity of the spit, (2) tsunami spit overtopping, and (3) coseismic beach retreat since the A.D. 1700 great earthquake in the Cascadia subduction zone. Wreck debris was (1) initially scattered along the spit ocean beaches, (2) washed over the spit by nearfield tsunami (6–8 m elevation), and (3) remobilized in beach strandlines by catastrophic beach retreat. Historic recovery of the spit (150 m beach progradation) and modern foredune accretion (>5 m depth) have buried both the retreat scarp strandlines and associated wreck artifacts. The recent onshore sand transport might re‐expose heavy ship remains in the offshore area if the wreck grounded in shallow water (<20 m water depth of closure). © 2011 Wiley Periodicals, Inc.     

Examining Fluvial Stratigraphic Architecture Using Ground‐Penetrating Radar at the Fanta Stream Fossil and Archaeological Site,Central Ethiopia

The Fanta Stream site is an archaeological and paleontological locality in Addis Ababa, Ethiopia. The site contains a rich assemblage of fossil mammals and Acheulean artifacts of approximately 600 ka located in a rare high‐altitude context. A ground‐penetrating radar (GPR) survey was conducted in order to provide three‐dimensional imaging of the subsurface, which the authors use to interpret the geometry and distribution of fossil‐containing stratigraphic units. Utilizing the stream's natural cut bank exposure, we calibrate GPR data to known geologic units through radar facies analysis. Shallow, high‐amplitude coherent reflection geometries are attributed to volcanic tuff deposits, as these units exhibit subparallel continuous reflections consistent with planar stratified sedimentary deposition. Deeper, discontinuous reflection packages are interpreted as conglomeritic, fossil‐containing deposits. The results of the GPR survey outline the location of the Fanta Stream's paleodepositional features as well as suggest the extent of fossiliferous stratigraphic units for use in future excavations.     

Molluscan assemblages from archaeological deposits

Research about the impact of prehistoric human subsistence strategies upon prey populations of shellfish is based on the assumption that trends in shell size are directly related to collection strategies. A shell midden on San Juan Island, Washington, where archaeological research is sponsored by the University of Washington and hosted by the National Park Service, provides large samples of shells from separate archaeological deposits. the shells from each deposit produce size-frequency distributions that vary in shape (modality). Because several factors (the original prey population, the method of collection and transport, the environment of deposition, and post-depositional processes) affect the size-frequency distribution differentially, the shell measurements do not provide the direct archaeological information expected.     

Internal structure of a trough blowout, determined from migrated ground-penetrating radar profiles

Ground‐penetrating radar (GPR) was used to investigate the relationship between the geomorphological development of a large aeolian trough blowout and the stratigraphy and internal sedimentary structure of its associated deposits. Although analogous, many of the data‐processing techniques routinely applied in seismic reflection are very rarely applied in GPR studies. In this study, a simple migration program was used that significantly enhanced the quality of GPR images from a large trough blowout at Raven Meols on the Sefton coast, northwest England. These improvements aided subsequent data interpretation, which was achieved through application of the principles of radar stratigraphy. GPR shows the pre‐blowout dunes to have a complex internal structure that suggests they were formed in the presence of at least a partial vegetation cover. Subsequent to stabilization of these dunes a thin soil developed. This dune soil forms an important radar sequence boundary and delineates a complex topography beneath the depositional lobe of the blowout. The internal structure of the depositional lobe of the blowout does not conform to a model of simple radial foreset deposition, as derived from contemporary process studies reported in the literature. Instead, the pattern of deposition has been extensively modified by the antecedent dune topography and by varying spatial and temporal exposure to important sand‐transporting winds that is partly controlled by interactions between the regional wind pattern and local dune morphology. Trough blowout deposits in coastal aeolian sedimentary sequences are likely to be recognized by the presence of laterally continuous packets of relatively high‐angle cross‐strata, which often display a spatially‐variable radial dip pattern that is only very poorly or partially developed. In addition, a soil, or other surface representing a significant hiatus in dune deposition, is likely to underlie the blowout deposits, the topography of which will show a clear relationship to the dip and orientation of the overlying cross‐strata.     

How has coastal erosion affected the prehistoric settlement pattern of the boothbay region of maine?

Erosion of complex, rocky coasts has largely been neglected by geologists. Thus, a geo-archaeological study of coastal erosion was required before analysis of the prehistoric settlement pattern could be undertaken. Along the outer, wave-dominated coast of Maine, erosion is episodic, occurring when large storms raise water levels to new heights. Along the inner, tide-dominated coast, erosion occurs more frequently because unconsolidated sediments are exposed at low elevations in bedrock features. The shell midden archaeological sites of the Boothbay, Maine region are situated in the most rapidly eroding areas; therefore, it can be reasoned that localities without cultural deposits were never occupied. On the other hand, coastal erosion is widespread enough to insure that sites have been exposed to discovery by archaeological survey. Settlement pattern analysis of the study area is, therefore, not biased by differential preservation or discovery of archaeological sites.     

Application of GPR in the study of shallow subsurface sedimentary architecture of Modwa spit,Gulf of Kachchh

The coastline constitutes a very sensitive geomorphic domain constantly subjected to dynamic coastal processes. The study of its ever-changing physiography and stratigraphy provides a wealth of information on its history and evolution, in many cases at decadal and annual scales. The present study was carried out on the Modwa beach complex between Rawal Pir and Modwa, about 10 km east of Mandvi on the northern coast of the Gulf of Kachchh. The Modwa spit is a 7-km long WNW-ESE trending prograding amalgamated beach ridge complex that is about 0.5 km wide at its western end and 1.5 km wide at its eastern end. This Ground-Penetrating Radar (GPR) survey delineated a variety of the radar surfaces and radar facies which reflects not only large scale sedimentary architecture, but depositional facies of the beach ridge complex. These are bounding surfaces separating the radar facies outline beach ridge (br), washover (wo), coastal dune (cd) and swale (sw) depositional environments. The internal sedimentary structures like tangential, parallel, concave and convex upward stratifications could also be visualized from the GPR profiles. The architecture suggests the formation of this complex due to a combined process of eastward littoral drift of locally derived sediments and its onshore deposition by storms and eolian activities.     

Ground‐penetrating radar survey of the Sny Magill Mound Group,Effigy Mounds National Monument,Iowa

A ground‐penetrating radar (GPR) survey of 101 mounds at the Sny Magill Unit of Effigy Mounds National Monument, Iowa, demonstrates that GPR can be an effective tool to evaluate the structure and condition of mounds without damaging them. Ideal survey conditions and improved processing technology allow for the identification of strata within the mounds, as well as areas of post‐construction disturbance and possible archaeological features within the mounds. Provisional interpretations indicate that 60 are intact conical mounds with minimal post‐construction disturbance, and two show very strong evidence of containing interior burial platforms; 29 are badly damaged by non‐cultural or cultural activity; two are probable non‐cultural mounds; nine are reasonably intact linear and effigy mounds; one is an excavated effigy mound. GPR and other remote‐sensing techniques are highly recommended for mound investigation, but wherever possible such techniques need to be coordinated with mound excavation so as to test the remote‐sensing results. © 2008 Wiley Periodicals, Inc.     

Geophysical and Geoarchaeological Investigations at Aganoa Beach,American Samoa: An Early Archaeological Site in Western Polynesia

Archaeological investigations at Aganoa, a coastal site in American Samoa, western Polynesia, revealed a marine resources exploitation base for the early inhabitants of the island. A series of 19 radiocarbon age determinations indicates the principal period of site utilization began no later than 570 B.C., and probably earlier, and lasted for about 300 years. This site is squarely in the phase identified by previous scholars as “ancestral Polynesian.” Geophysical survey in the form of long, shore‐perpendicular transects showed the accretionary history of this beach and ridge area. Surprisingly, it revealed that the earlier ridges were directly below the modern ridge (i.e., progradation of this geomorphic feature had not occurred). The survey revealed a buried paleosol with little or no disturbance, which yielded a well‐preserved assemblage of plain and decorated ceramics, stone artifacts, fishhooks, and archaeofauna. No evidence of archaeological continuity was seen between the end of the terminal Lapita occupation and the later reoccupation of the site after about A.D. 700. This study demonstrates the utility and feasibility of using ground‐penetrating radar for the discovery of deeply buried coastal sites.     

探地雷达(GPR)在海南岛东北部海岸带调查中的应用 *

对海南岛东北部海岸带调查采用了探地雷达(GPR)研究海岸带沙体的结构、展布和沉积序列,取得了很好的效果。文章通过和有限的露头资料对比以及对反射波形态、结构的研究,确定了海滩脊、海岸沙丘的反射特征以及潜水面的位置。雷达图像显示五龙港古海滩脊由亚水平、不连续、高振幅和透镜状反射波组成;木兰头海岸沙丘已受到人类活动的扰动,短的、陡倾斜反射可能代表未受扰动的海岸风成沙的前积层。研究表明探地雷达是一种可靠、快速和经济的地球物理方法,在砂砾质海岸可产生高质量、高分辨率和连续的反射剖面,值得加以推广。     

Holocene coastal response to monsoons and relative sea-level changes in northeast peninsular Malaysia

Sedimentological, geomorphic, and ground penetrating radar (GPR) data are combined with optically stimulated luminescence data to define the Holocene evolution of a coastal system in peninsular Malaysia. The Setiu coastal region of northeast Malaysia comprises five geological and geomorphic units representing distinct evolutionary phases of this coastline. Estimated marine limiting point elevations indicate deposition of an early aggradational shoreline associated with a sea-level elevation of −0.1 to +1.7 m (MSL_PMVGD datum) between ∼6.8 ka and 5.7 ka, in agreement with previous sea-level studies from the Malay–Thai peninsula. A hiatus occurs in the record between ∼5.7 ka and 3.0 ka, possibly due to a relative sea-level oscillation and shoreline erosion. Long-term relative sea-level fall and possible still-stands created strandplains that are interrupted by aggradational to transgressive paleo-barrier and estuary formation corresponding with brief episodes of RSL rise. Analyses of GPR facies and OSL ages suggest annual clinoform deposition, with geometries dictated by variations in ENSO. These data demonstrate the utility of high resolution studies of coastal facies as useful proxy indicators for paleoclimate studies at subdecadal to millennial time-scales.     

Archaeological exploration using magnetic and GPR methods at the first court of Hatshepsut Temple in Luxor, Egypt

The Hatshepsut Temple at Luxor, southern Egypt was built as a garden for Amun, and the first court indeed had exotic trees and vegetations. The pathway to the temple was along a sphinx-lined causeway linking the valley to pylons, which are missing now. As an effort to outline remains of the vanished garden and missing pylons and any other possible archaeological structures at this first court site, an extensive integrated magnetic/ground-penetrating radar (GPR) geophysical survey was conducted. The magnetic survey covered the entire area of the first court (100?×?60 m), while the GPR survey covered only an area of 50?×?50 m. The acquired GPR data were processed and presented as 2-D depth sections providing a reasonable vertical/horizontal resolution for the upper 6 m of the investigated site. The acquired magnetic data was processed and presented as 2-D image. The integrated interpretation of the acquired GPR and magnetic data revealed some archaeological features including a rectangular depression which is presumably an ancient man-made pond in the garden of the temple, a rectangular feature that may be a foundation of the missing pylon of the temple, and a suite of aligned anomalies that could be the remnants of sphinx. Such findings reflect the archaeological potentiality of the surveyed site and outline the extension of the temple. Meanwhile, these results necessitate further geophysical investigation or archaeological excavation to be confirmed.     

Earthquake-induced burial of archaeological sites along the southern Washington coast about A.D. 1700

Although inhabited by thousands of people when first reached by Europeans, the Pacific coast of southern Washington has little recognized evidence of prehistoric human occupation. This apparent contradiction may be explained partly by geologic evidence for coastal submergence during prehistoric earthquakes on the Cascadia subduction zone. Recently discovered archaeological sites, exposed in the banks of two tidal streams, show evidence for earthquake-induced submergence and consequent burial by intertidal mud about A.D. 1700. We surmise that, because of prehistoric earthquakes, other archaeological sites may now lie hidden beneath the surfaces of modern tidelands. Such burial of archaeological sites raises questions about the estimation of prehistoric human population densities along coasts subject to earthquake-induced submergence. © 1996 John Wiley & Sons, Inc.     

Geoarchaeological and chronostratigraphical investigations of open‐air sites in the Geelbek Dunes,South Africa

The Geelbek Dunes located north of Cape Town, South Africa, are an active, northward migrating dune field. Interdunal deflation hollows temporarily expose former land surfaces that are associated with archaeological sites. These open‐air sites shed light on large‐scale patterns of Middle and Later Stone Age settlement and augment the information gained from well‐stratified, but spatially limited caves, rock shelters, and coastal shell middens. Based on paleopedological and sedimentological parameters, three former land surfaces were identified and associated with different assemblages. A chronostratigraphy of the various land surfaces was established by applying optically stimulated luminescence (OSL) dating. The youngest former land surface is represented by a dune generation (AD2) which stabilized at a maximum of 5 ka. An older dune generation (AD1) shows a more heterogeneous age pattern where deposition started at ca. 27 ka with a maximum estimated age of stabilization at ca. 10 ka. Both of these dune generations overlie a weathered calcrete complex of Middle to Late Pleistocene age. While the third dune generation (AD0) was observed between underlying calcrete layers, samples taken from this unit could not be dated. © 2008 Wiley Periodicals, Inc.     

Shell Middens,Cultural Chronologies,and Coastal Settlement on the Rhode River Sub‐Estuary of Chesapeake Bay,Maryland, USA

North America's Atlantic Coast has been a focus of human settlement and subsistence for millennia, but sea‐level rise, sedimentation, and other processes pose significant challenges for archaeological research. Radiocarbon dating of 31 shell middens near the Rhode River Estuary, Maryland provides an opportunity to evaluate human land use, settlement, and cultural chronologies on the Chesapeake Bay. Sixty calibrated radiocarbon dates on eastern oyster (Crassostrea virginica) shell and charcoal demonstrate that Native Americans, colonial, and historic peoples harvested oysters and other shellfish from at least 3200 years ago through the 19th century. The number of dated sites increases during the Late Woodland period after about 1000 cal yr B.P., a factor probably related to greater site visibility and preservation, as well as increased human exploitation of the watershed. Accumulation rates for five of the shell middens provide preliminary indications that some of the sites accumulated rapidly suggesting, along with other evidence, that many of the region's shell middens were logistical or perhaps seasonal camps. Our study demonstrates the importance of regional watershed surveys and radiocarbon dating programs to help build and refine cultural chronologies in coastal regions threatened by sea‐level rise and other processes.     

Use of two-dimensional electric resistivity and ground penetrating radar for archaeological prospecting at the ancient capital of Egypt

Two-dimensional (2-D) resistivity and ground penetrating radar (GPR) surveys facilitate tracing of buried archaeological relics at the archaeological site of the Tell El Rabi'a, southwestern Cairo. These surveys also provide information on variations in depth of the groundwater table, which affect both exhumed and buried archaeological remains. The 2-D electrical resistivity profiles obtained show some high anomalies (up to 6900 Ω m). Based upon on-site calibration at partly exhumed sites, such anomalies are interpreted as pillar crowns and wall-like structures of hard limestone of the Hathour temple. The low background resistivities are interpreted to represent riverine deposits with differing moisture (or saturation) characteristics. The results of the GPR survey show three forms of high-amplitude radar anomalies, denoted as “P, H and R”. The “P” anomalies have semi-hyperbolic shapes, which suggest the presence of thin buried walls. The second, near-horizontal group of anomalies, “H”, may be either due to the presence of thick buried walls or arise from coincidental parallel alignment of survey lines with buried linear structures. The third group of GPR anomalies “R” is composed of chaotic reflections, and interpreted to depict buried stone-filled chambers. Some un-exhumed parts of the study area show weak radar reflections with occasional highly attenuated radar signals. These phenomena are ascribed to differing compaction and moisture characteristics of riverine soil layers. Recommendations with regard to archaeological site-excavation, preservation of archaeological relics, and soil conservation are submitted.     

A dating intercomparison study on Late Stone Age coastal midden deposits,South Africa

The southern and western coastlines of South Africa have an extensive archaeological record with many sites associated with widespread eolian deposits. While much of this rich archaeological record is based on cave sites, evidence of Late Stone Age occupation is additionally preserved in the form of open‐site shell middens. We present here a comparative study of the application of amino acid racemization (AAR), optically stimulated luminescence (OSL), and radiocarbon analyses to three Late Stone Age (LSA) midden sites found within dunes on the southern coastline of South Africa. Preliminary geochronological analyses suggest that middens offer opportunity to fill in gaps in what is still a fragmentary archaeological record. Results show OSL and radiocarbon ages in good agreement, illustrating the potential to date not only the middens but also the surrounding dunes that constituted the dwelling sites. AAR results show increasing ratios with age and also that the application of paired shell and “whole rock” AAR can provide insights into the degree of biogenic sediment recycling at buried midden sites. However, the work also highlights that caution is required when OSL sampling sediment associated with middens which may have undergone human disturbance and that further work is required to improve the regional marine reservoir correction for radiocarbon dating in this part of South Africa. The study also illustrates that AAR will only provide useful data provided that middens have been sufficiently deeply buried to overcome fluctuations in environmental variables that affect the racemization rate and that inter‐genus comparisons should be avoided. © 2008 Wiley Periodicals, Inc.     

Anatomy and sedimentary model of a hooked spit (Sylt,southern North Sea)

A sedimentary model for hooked spit depositional systems based on ground‐penetrating radar and sedimentological data is presented. The recurved main spit of Sylt Island (southern North Sea) is dominated by migrating sand dunes; the investigated hooked spit exhibits a system of foredune ridges, oriented perpendicular to the dunes of the recurved spit. The development of the hooked spit is related closely to the presence of an adjacent tidal inlet, where strong tidal currents and a steep bathymetry prevent a further northward progradation of the main spit and trigger a deflection from northerly‐directed to easterly‐directed net sediment transport. Ground‐penetrating radar data and shallow sediment cores reveal the sedimentary architecture of the hooked spit in high resolution and allow the proposition of a genetic stratigraphic model. It is shown that the growth of the hooked spit is controlled by the interplay of alongshore migrating foreshore beach drifts under fair‐weather conditions and strong erosional events, interpreted as the result of rare severe storms. These storms may excavate scarps in the backshore, which play an important role in the development of foredune ridges. Accelerator mass spectrometry ¹⁴C ages indicate an absolute age of at least 1300 years for the hooked spit, which possibly correlates with strengthened erosion of the main spit. In contrast to the main spit, where the sediment budget is negative nowadays, growth of the hooked spit beach accelerated significantly during the last decades. This effect can probably be attributed to enhanced beach‐nourishments updrift along the main spit and makes the investigated hooked spit a natural laboratory to study the influence of increasing sediment supply into a system developing under the conditions of sea‐level rise. The study shows that the same external forces lead to distinct progradational processes along one barrier‐spit system.     

Evolution of landscapes on the double mountain fork of the brazos river,West Texas: Implications for preservation and visibility of the archaeological record

The Double Mountain Fork of the Brazos River is an ephemeral stream that flows across the western Rolling Plains of West Texas. Intensive pedestrian archaeological survey, covering some 8700 acres of the drainage, produced a site inventory with a general paucity of identifiable Paleoindian and Early to Middle Archaic components, whereas Late Archaic and Late Prehistoric sites were widespread and found in a diversity of landscape positions. Geoarchaeological investigations were conducted in conjunction with this survey and later testing activities, and suggested that much of this temporally and spatially skewed archaeological record may be attributable to the evolution of landscapes during the late Pleistocene and Holocene time period, rather than original occupation intensities. Most of the landscape in the study area has been subject to erosional stripping, but in selected localities late Pleistocene and Holocene depositional landform-sediment assemblages of fluvial, alluvial/colluvial fan, and eolian origin are preserved. With few exceptions, however, depositional contexts or stable geomorphic surfaces more than 3000 years old are erosionally truncated, completely absent, or deeply buried. As a result, a bias is imposed that renders older cultural records either poorly preserved or deeply buried and of low visibility to traditional survey techniques. Similar natural formation processes are likely at other locations on the western Rolling Plains, and should be considered during interpretation of prehistoric population dynamics in the area. The biases imposed by such natural formation processes on the western Rolling Plains are slightly different from other areas in the Southern Great Plains of the United States, but in most cases the known archaeological record corresponds with opportunities for preservation and visibility provided by geologic trajectories, and may reflect little on spatial and temporal discontinuities in prehistoric cultural activity.