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1.
This study reviews the occurrence and potential of bryozoans within lithic artifacts and also sets out a methodology for their use in sourcing and discusses the advantages and disadvantages of this approach. We present case studies from our own research and from the literature on using bryozoans in sourcing archaeological lithic artifacts. Fossil bryozoans of different ages and clades can be effectively used to determine the material source of lithic artifacts from a variety of prehistoric ages. The case studies included in this report span the stratigraphic range of bryozoans from the Ordovician to the Neogene. The bryozoans came from four different orders: trepostome, fenestrate, cyclostome, and cheilostome. The use of these lithic artifacts ranged back to 25 ka. Although the majority of the fossil bryozoans were incidental in the artifacts, the bryozoans were still useful for determining their original source rock. The improved searchable online paleontologic databases allow for more efficient use of fossil bryozoans to constrain the stratigraphic and paleogeographic distribution of source outcrops. Although generally underutilized in sourcing prehistoric lithic artifacts, it is clear that by analyzing bryozoans, an increased understanding of the lithologic nature of these materials could be gained by the archaeological community.  相似文献   

2.
Recent exploratory studies have suggested the potential of magnetic susceptibility (MS) as a rapid and low‐cost sourcing technique for lithic archaeological materials. Most commercially available susceptibility instruments, however, do not have the sensitivity to characterize weakly susceptible cherts and silicified woods. Comparative results from nine chert, two silicified wood, a porcellanite, and four obsidian sources using a highly sensitive, calibrated, and magnetically‐shielded instrument allow exploration of MS variability within and between geological sources. Color, texture, grain size, and large inclusions of cherts and obsidians are not straightforward determinants of MS. Weathering rinds (patinas) and cortex from a variety of cherts yield reduced MS values, as does a recrystalized cobble of Rio Maior flint, indicating that magnetic mineral removal during chemical weathering and diagenesis is more prevalent than staining or other mineral penetration of cobbles. In situations of multiple overlapping MS ranges, analysis is limited to discriminating cherts with high or low MS range distributions, for example in an atypicality index. Some silicified woods, obsidians, and porcellanites possess a much greater range of intersource variability, and thus sourcing analysis is more likely to be broadly successful using the susceptibility of these materials. Unexpected results from an archaeological test using a historic lithic assemblage from Azinheira, Portugal, indicate that assemblage MS may be influenced by practices of raw material selection. Understanding variability in lithic MS has relevance for the design of most source geochemical sampling, as well as the behavioral interpretations that result from such investigations. © 2002 Wiley Periodicals, Inc.  相似文献   

3.
The Shi'bat Dihya 1 site in western Yemen, dated by optically stimulated luminescence to 55 ka, provides insight into the Middle Paleolithic peopling of the Arabian Peninsula. The archaeological layer is interstratified within thick, sandy silt floodplain deposits filling a piedmont basin. Luminescence dates, lack of soil development, and gypsum precipitation indicate a high accretion rate of the floodplain during Marine Isotope Stage 3, in connection with a (semi)‐arid environment. Rapid overbank sedimentation was likely a result of the remobilization of loess material deposited on the Yemeni Great Escarpment at the periphery of the adjacent Tihama coastal sand desert or of other sources. Fabric and size analyses of the lithic artifacts, together with spatial projections, indicate site modifications by floods. Primary modifications include (1) selective accumulation of medium‐sized lithic pieces as a result of hydraulic sorting, (2) bimodal orientation of artifacts, and (3) ripple‐like arrangement of lithics and bone/tooth fragments. The overrepresentation of teeth may also be a consequence of sorting. Although floods have distorted the original site patterning, long‐distance transport of artifacts by water can be excluded, as indicated by relatively high refitting rate, close proximity of artifacts derived from the same block of raw material, and lack of abrasion of the pieces. Therefore, the site is considered “geologically” in situ because its remobilization by water occurred shortly after human abandonment. This study also stresses that the effective preservation of a site cannot be assessed without careful taphonomic study, even in a potentially favorable depositional context such as silty alluvium.  相似文献   

4.
Over the last ninety years or so, archaeological field work on outcrops of raw materials in western France has allowed researchers to identify the use of a large number of deformed rock types in lithic industries. These materials include Armorican phtanites, which are cherts that were widely exploited during the Mesolithic, principally during its final phase (5500–5000 yrs cal. B.C.). Because of variations in the mineralogical composition and physical properties of phtanites, different mechanical properties are exhibited by samples from the four main geological formations containing this rock type in the Armorican Massif of western France. These geological and mechanical parameters influenced the quantity of rock used and the knapping methods employed. They also influenced the tool types produced and their transfer, as recorded in archaeological sequences. The types of raw materials used are also controlled by the distance to sources of coastal flint pebbles or other autochthonous siliceous rocks. Therefore, the role of raw material properties in the creation and persistence of techno‐cultural or economic characteristics is different for each type of phtanite and yields fundamental information on the interaction of society with the geological environment. © 2010 Wiley Periodicals, Inc.  相似文献   

5.
Characterizing raw material of stone tools used by Late Neolithic and Copper Age communities is important for interpreting access to available sources and establishing regional routes of distribution. Ichnological analysis may be used to help characterize lithic material and determine the source of artifacts. Here we report for the first time the existence of trace fossils in artifacts from the Late Neolithic and Copper Age of southern Spain. Ichnological analysis indicates a trace fossil assemblage consisting of relatively scarce small‐sized Chondrites and abundant Phycosiphon. A regional survey of natural outcrops and chert quarries indicates the presence of discrete trace fossils only in the samples from geological formations that are part of the Campo de Gibraltar Complex. Ichnological composition in these samples is similar to that discerned in the artifacts and suggests that this was the probable source of the chert used in tool manufacture. © 2010 Wiley Periodicals, Inc.  相似文献   

6.
Bizat Ruhama, an Early Pleistocene site located in the southern coastal plain of Israel, has yielded a single archaeological horizon dating to the Matuyama chron. Recent technological and zooarchaeological studies suggest evidence of near in situ hominin occupations taking place in a semiarid climatic setting. Such an archaeological context is rare for the Early Pleistocene and must be corroborated through reconstruction of site formation processes. This paper offers a microstratigraphic view of the site based on results from a micromorphological and granulometric study aimed at reconstructing site formation processes. Results show that the bone and lithic specimens were deposited near their excavated provenience, in a depressed, seasonally waterlogged area, and were subsequently slightly displaced and buried by surface sediment. We infer that the Bizat Ruhama deposit represents one or a few hominin occupations taking place on the surface of an undulating inter‐dune depression under a semiarid Mediterranean climate. © 2010 Wiley Periodicals, Inc.  相似文献   

7.
Test excavations in 2005 and 2006 of the Little Salt Spring mortuary pond in Southwest Florida (USA) yielded two exotic stone pendants indirectly dated to the Middle Archaic (7000–5000 14C year B.P.). Hand‐specimen petrographic observation, combined with non‐destructive environmental scanning electron microscopy, X‐ray fluorescence spectroscopy, and whole‐rock X‐ray diffraction, identified the pendants as (1) a mica‐plagioclase‐edenite amphibolite or schist and (2) an intermediate pyroxene‐ and/or amphibole‐bearing granitoid. Provenance was broadly constrained to a number of potential sources in the southern Appalachian Piedmont of the United States (at a minimum distance of 650 km from the archaeological findspot) utilizing the United States Geological Survey's National Geologic Map Database lithologic search tool (GEOLEX) and Mineral Resources On‐Line Spatial Data GIS database. Due to the absence of lithologic matches within the state of Florida, we propose that the two artifacts most likely arrived at Little Salt Spring through down‐the‐line exchange of materials of prestige value with geologic origins in the southern Appalachian Piedmont, arguing for the existence of small‐scale long‐distance lithic exchange networks reaching into Archaic Florida. From a methodological standpoint, this study illustrates the potential utility of data collected under nonideal, non‐destructive analytical conditions for deriving meaningful archaeological interpretations.  相似文献   

8.
Archaeological surface surveys have located open‐air sites on cropland in the Sierra de Atapuerca (Burgos, Spain). To what degree agricultural disturbances have impacted archaeological site integrity is poorly defined and may greatly affect interpretations of prehistoric land use. This paper presents the results of three experiments concerned with the effects of tillage on artifact distribution, focusing specifically on lateral and vertical artifact displacement. We demonstrate highly variable horizontal displacement of artifacts by plowing and overall downward movement of lithic materials within the soil. This results in an expansion of site boundaries and reduction of surface artifact density, yielding a biased and unrepresentative picture of past human activity. More experimental studies are needed to better define agricultural disturbances to surface archaeological assemblages. © 2008 Wiley Periodicals, Inc.  相似文献   

9.
Identifying the geological and geographical origin of lithic raw materials is critical to effectively address prehistoric forager raw material economies and mobility strategies. Currently, Paleolithic archaeology in Belgium lacks a systematic sourcing strategy to effectively substantiate detailed interpretations of prehistoric hunter‐gatherer behavioral change across time and space. This pilot study evaluates the potential to “fingerprint” flint from the Mons Basin, western Belgium, using the laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) technique and a multivariate statistical analysis of 87 geological samples and 39 Gravettian period chipped stone artifacts. We reappraise two hypotheses raised by previous scholars based on visual raw material identification: (1) the Gravettian occupants of Maisières‐Canal supplied themselves with “black flint” from one single source; (2) the sites Rhens and Koblenz‐Metternich yielded artifacts indicative of long‐distance transfer of western Belgian flint into the German Rhineland, ca. 260 km from the primary source area. Our results demonstrate the validity of LA‐ICP‐MS data with flint and compositional data analysis for fingerprinting discrete geological formations from the Mons Basin. We suggest multiple source provisioning for Maisières‐Canal. Geochemical characterization of other potential flint sources is required to validate the long‐distance transfer hypothesis of western Belgian “black flint” into the German Rhineland.  相似文献   

10.
Research for evaluation of geologic hazards involving earthquakes and volcanic eruptions in southern Argentina seems to have historically received little attention. Nevertheless, the relatively small work done indicates a Neogene tectonic architecture in the area with capability of generating potential hazardous earthquakes in a growing population region. Seismicity and some morphotectonic evidences of Quaternary activity of the Magallanes–Fagnano left‐lateral fault system in the transform boundary between South America and Scotia plates, are analysed in this paper. This fault system is considered to be an important seismogenic source, responsible for large earthquakes that have occurred in southern Argentina. Some examples from the South and Austral Andean Volcanic Zones are also examined in order to show recent volcanic activity which also generated crustal seismicity. Preliminary hazard estimation clearly shows the presence of both potentially active volcanic centres in southern Patagonia that may also trigger seismicity and the high probability for large crustal earthquake generation. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

11.
Accretionary desert pavements on the eastern Libyan Plateau of central Egypt support a rich Middle and Upper Paleolithic artifact assemblage exhibiting intensive blank production and minimal tool production. These assemblages appear to be in primary context with numerous examples of lithic refits showing on‐site lithic production. However, the smallest (length ≤2.5 cm) archaeological fragments are recovered at a much lower rate on this desert pavement surface than expected given comparable data from lithic assemblages in cave and shelter contexts in France. Excavation of archaeological contexts on the Libyan Plateau reveals the loss of small artifact fragments into the subsurface due to aeolian accumulation of silts, whereas geomorphic examination of desert pavement surfaces suggests a potential for relatively isolated bioturbation as a source of lateral and vertical disturbance of desert pavement surfaces over small areas. Archaeologists should be aware of the potential for long‐term assemblage stability as well as small artifact burial in surficial desert pavement contexts.  相似文献   

12.
Lithic artifacts buried in the soil profile may be transported to the surface during tillage‐induced kinetic sieving, differential erosion, or swell–shrink cycles of clays and become part of a rock fragment mulch. Archaeologically, these manifestations are recognized as surface scatters. Although artifacts at the soil surface are difficult to relate to the local stratigraphic context, surface assemblages may provide information on lithic industries and the archaeological significance of sparsely explored regions. Through in situ investigation of surface material in 60 1 × 1 m2 plots in the Tembien district in the northern Ethiopian highlands, we show that rock fragment mulches can contain a significant number of lithic artifacts and we provide evidence for mid‐Pleistocene occupation of a site. Considering that severe rill and gully erosion may be a threat to the archaeological heritage and that well‐dated African Middle Stone Age sites are rare, we conclude that the region deserves more attention for archaeological research. © 2009 Wiley Periodicals, Inc.  相似文献   

13.
Located on the south of the Gangdese,the Qiuwu Formation has traditionally been considered as Eocene coal-bearing clastic sediments consisting of sandstone,mudstone and conglomerate,unconformably on top of Gangdese batholith.However,its precise age and depositional environment remain ambiguous.Here,we present a newly measured stratigraphic section near the Ngamring County,western Xigaze.Detrital zircon U-Pb ages were also applied to trace the provenance of sediments and to constrain the maximum depositional age of the Qiuwu Formation.Sedimentary facies analyses indicate subaqueous fan and alluvial fan depositional environments.Clast composition of the conglomerate is dominated by magmatic rocks at the lower part,while chert and mafic detritus occur in the upper part,suggesting a southern source.Sandstone modal analyses indicate that the compositions of quartz,feldspar and lithic grains changed from transitional arc to dissected arc,implying the unroofing of the Gangdese arc.Detrital zircon U-Pb ages of the Qiuwu Formation are compared with those from Gangdese magmatic rocks and Yarlung-Zangbo ophiolites,suggesting that the Gangdese arc is a main source of the Qiuwu detritus and that the southern source played a role during the later stage.The major peak of detrital zircon ages is at 45-55 Ma,which corresponds to Linzizong volcanic rocks in southern Gangdese arc.The weighted mean age of the five youngest zircons from the lower part of the section is 21.0 ± 2.2 Ma,suggesting that the Qiuwu Formation was deposited in early Miocene,coeval with other conglomerates exposed along the southern margin of Gangdese.Combining new observations with previously published data,we propose that the provenance of the Qiuwu Formation had shifted from a single northern source to double sources from both the north and the south.Activities of Great Counter Thrust were primarily responsible for the shift by making the south area a high elevation to provide sediments for the Qiuwu Formation.  相似文献   

14.
The late Palaeozoic western Tianshan high‐pressure /low‐temperature belt extends for about 200 km along the south‐central Tianshan suture zone and is composed mainly of blueschist, eclogite and epidote amphibolite/greenschist facies rocks. P–T conditions of mafic garnet omphacite and garnet–omphacite blueschist, which are interlayered with eclogite, were investigated in order to establish an exhumation path for these high‐pressure rocks. Maximum pressure conditions are represented by the assemblage garnet–omphacite–paragonite–phengite–glaucophane–quartz–rutile. Estimated maximum pressures range between 18 and 21 kbar at temperatures between 490 and 570 °C. Decompression caused the destabilization of omphacite, garnet and glaucophane to albite, Ca‐amphibole and chlorite. The post‐eclogite facies metamorphic conditions between 9 and 14 kbar at 480–570 °C suggest an almost isothermal decompression from eclogite to epidote–amphibolite facies conditions. Prograde growth zoning and mineral inclusions in garnet as well as post‐eclogite facies conditions are evidence for a clockwise P–T path. Analysis of phase diagrams constrains the P–T path to more or less isothermal cooling which is well corroborated by the results of geothermobarometry and mineral textures. This implies that the high‐pressure rocks from the western Tianshan Orogen formed in a tectonic regime similar to ‘Alpine‐type’ tectonics. This contradicts previous models which favour ‘Franciscan‐type’ tectonics for the southern Tianshan high‐pressure rocks.  相似文献   

15.
The petrology of first cycle (unmodified) and second cycle (reworked) sand at the termini of eleven valley glaciers eroding coarse- to fine-grained bedrock types is determined in order to evaluate the origin and mechanical durability of lithic sands. First cycle sands are coarse- to medium-grained, poorly sorted, fine-skewed, non-modal lithic sands with an average composition of Q21F6L73. Grain-size distributions do not vary with composition or source rock types, although sands derived from finer grained source rocks contain more lithic fragments than sands from coarser grained sources. By contrast, second cycle sands are medium-grained, poorly sorted, fine- to coarse-skewed arkosic to lithic sands with an average composition of Q19F40L41, and contain fewer lithic fragments than do first cycle sands. We propose that the origin, mechanical durability and survival potential of lithic fragments are related to the types and abundances of their internal planes of weakness, and the particular stress field of the transporting medium. As a result of abrasion, glacial clasts and lithic fragments are subjected to shear stress so that fractures propagate along intracrystal and intercrystal planes of weakness resulting in a continuous grain-size spectrum of lithic fragments and monomineralic grains irrespective of the type of source rock. Upon subsequent aqueous transport in the proglacial environment lithic fragments are subjected to point-loading during saltation in addition to shear stress. Point-loading produces extensional fractures which preferentially propagate along intercrystal planes of weakness, so the lithic fragments break into smaller monomineralic grains and/or lithic fragments. Lithic fragments of very coarse sand-size are abundant in first cycle sands, thus refuting, at least for glacial sands, the widely held view that grains of this size are deficient in nature. The presence of fewer grains of this size in second cycle sands indicates that very coarse sand-size lithic fragments can survive recycling, but in greatly reduced proportions due to breakage.  相似文献   

16.
A study of the Narrabeen Group in the southern part of the Sydney Basin has provided a more complete understanding of the conditions of deposition in the area during the Lower Triassic. The sedimentology of the sequence indicates that several different types of fluvial deposits are represented, with an upward succession from piedmont conditions with braided streams to a swampy deltaic plain. This sequence is interpreted as the onshore portion of a slow marine transgression, probably brought about by declining erosive activity in the hinterland.

The palaeocurrent pattern shows that drainage was principally to the south‐southwest, parallel to the basin axis, and the lateral transition from quartzose to lithic sediments across the basin can be interpreted as a blending of sediment from western and northern source areas. In addition several influxes of material from a source east of the present coastline are indicated, with reworked volcanic debris being introduced into the south coast district. This southeasterly source area did not greatly impede the drainage of the basin during lower Narrabeen deposition, but was responsible for a major diversion of stream patterns as the topmost beds were laid down. This diversion was completed by a northeasterly drainage pattern during deposition of the overlying Hawkesbury Sandstone.  相似文献   

17.
This work presents an evaluation of various methods for in situ high‐precision Sr and Pb isotopic determination in archaeological glass (containing 100–500 μg g?1 target element) by nanosecond laser ablation multi‐collector‐inductively coupled plasma‐mass spectrometry (ns‐LA‐MC‐ICP‐MS). A set of four soda‐lime silicate glasses, Corning A–D, mimicking the composition of archaeological glass and produced by the Corning Museum of Glass (Corning, New York, USA), were investigated as candidates for matrix‐matched reference materials for use in the analysis of archaeological glass. Common geological reference materials with known isotopic compositions (USGS basalt glasses BHVO‐2G, GSE‐1G and NKT‐1G, soda‐lime silicate glass NIST SRM 610 and several archaeological glass samples with known Sr isotopic composition) were used to evaluate the ns‐LA‐MC‐ICP‐MS analytical procedures. When available, ns‐LA‐MC‐ICP‐MS results for the Corning glasses are reported. These were found to be in good agreement with results obtained via pneumatic nebulisation (pn) MC‐ICP‐MS after digestion of the glass matrix and target element isolation. The presence of potential spectral interference from doubly charged rare earth element (REE) ions affecting Sr isotopic determination was investigated by admixing Er and Yb aerosols by means of pneumatic nebulisation into the gas flow from the laser ablation system. It was shown that doubly charged REE ions affect the Sr isotope ratios, but that this could be circumvented by operating the instrument at higher mass resolution. Multiple strategies to correct for instrumental mass discrimination in ns‐LA‐MC‐ICP‐MS and the effects of relevant interferences were evaluated. Application of common glass reference materials with basaltic matrices for correction of ns‐LA‐MC‐ICP‐MS isotope data of archaeological glasses results in inaccurate Pb isotope ratios, rendering application of matrix‐matched reference materials indispensable. Correction for instrumental mass discrimination using the exponential law, with the application of Tl as an internal isotopic standard element introduced by pneumatic nebulisation and Corning D as bracketing isotopic calibrator, provided the most accurate results for Pb isotope ratio measurements in archaeological glass. Mass bias correction relying on the power law, combined with intra‐element internal correction, assuming a constant 88Sr/86Sr ratio, yielded the most accurate results for 87Sr/86Sr determination in archaeological glasses  相似文献   

18.
Relict fluvial and lacustrine deposits in the interior of Oman near Saiwan consist of waterlain breccias with pebble imbrications and current ripples, covered by algal laminites containing calcified reeds and charcoal pieces. Geomorphological evidence suggests that the palaeolake covered a maximum surface of 1400 km2 and had a maximum depth of about 25 m. Optically stimulated luminescence (OSL) and thermally transferred OSL dating indicate that this palaeolake existed sometime between 132 and 104 ka. The rich archaeological evidence in the area suggests substantial human occupation, possibly at the time when Palaeolake Saiwan existed. Interestingly, the lithic traditions of the archaeological material show no clear relation to coeval findings from neighbouring areas, putting a question mark on the origin of the culture found at Saiwan. This finding raises questions concerning the origin of the population inhabiting Saiwan, as the site lies along one possible route for the dispersal of anatomically modern humans out‐of‐Africa. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

19.
Understanding site formation processes is crucial for interpreting archaeological context patterns and hominin behaviour as these affect the preserved condition of a site and the integrity of archaeological remains. The fluvio‐lacustrine sequences in the Nihewan Basin of North China are rich sources of early Pleistocene archaeological sites, which offer an important opportunity to investigate human evolution and adapted behaviours in East Asia. Although many Palaeolithic sites have been reported from the Nihewan Basin, North China, few of them focus on site formation processes before interpreting the hominin behaviour patterns. Here, we present a site formation study of four archaeological layers (Layers 6D, 6C, 6B and 6A) in Trench 1 from the Donggutuo (namely DGT‐T1) site in the Nihewan Basin with an age of 1.1 Ma. Through the study of sedimentary contexts, spatial distributions of artefacts and fossils, intra‐assemblage category ratios, debitage size distributions, lithic abrasion, artifact orientation and planar dip, our results show that all the layers had been disturbed by low‐energy sheet wash across the lake shore setting, but to differing extents. The post‐depositional disturbance caused by water decreased from the lower to the upper layers, from Layer 6D to Layer 6A. This indicates that the archaeological remains in DGT‐T1 have not been subject to significant natural modifications and are thus suitable for studying early hominin behaviour in North China. Copyright © 2019 John Wiley & Sons, Ltd.  相似文献   

20.
In this provenance study of late Palaeozoic metasediments of the Eastern Andean Metamorphic Complex (EAMC) along the south Patagonian proto-Pacific margin of Gondwana, the palaeogeological setting of the continental margin in Devonian–Carboniferous and Permian times is reconstructed. The study is based on detrital heavy mineral contents, chemical compositions of tourmaline grains, and whole rock element and Nd-Sr isotopic compositions. Element and isotopic compositions reveal that Devonian–Carboniferous metaturbidites deposited before the development of a Late Carboniferous–Permian magmatic arc along the margin were mainly fed from felsic, recycled, old continental rocks. The last recycling phase involved erosion of metasediments that were exposed in Patagonia. Feeder systems to the basin cut either through epidote-rich or garnet-rich metasediments. In Permian time, EAMC metaturbidites were deposited next to the evolving magmatic arc and were derived from felsic, crustal rocks. Two provenance domains are recognised. The metasediments of the northern one are chemically similar to those of the Devonian–Carboniferous metasediments. This domain was fed from the metasedimentary host rocks of the magmatic arc. The southern domain probably was fed from the arc proper, as indicated mainly by the dominance of metaplutonic lithic fragments, abundant detrital biotite, and the major element composition of the metasediments.  相似文献   

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