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1.
Prehistoric cultural material is commonly composed of chert, due in large part to its physical properties that are conducive to tool manufacture. Despite its ubiquity, archaeologists are faced with an arduous task when attempting to source chert artifacts to known quarries/deposits. The application of visible/near‐infrared reflectance (VNIR) spectroscopy to chert sourcing attains a cost‐efficient, fast, non‐destructive, and accurate means of identifying material type and geologic/geographic origin. This study examines the merits of VNIR spectroscopy within chert sourcing studies by highlighting a material‐based case study from the Dover Quarry sites, Tennessee. Results demonstrate the ability of VNIR spectroscopy to differentiate chert types from different geologic formations with 98% accuracy. However, accuracy significantly decreased when attempting to distinguish particular outcrops within the same formation. Although the application of VNIR spectroscopy to chert sourcing is in its experimental phase, the preliminary results compare favorably with other provenance techniques whose aim is to quantify inter‐outcrop variation. © 2011 Wiley Periodicals, Inc.  相似文献   

2.
史前人类向青藏高原扩散的过程和适应高海拔缺氧环境的机制是多学科关注的热点科学问题.青海湖盆地是青藏高原旧石器-中石器时代遗址分布最为丰富的区域,对这些遗址出土的石制品原料的分析有助于深入理解青藏高原史前狩猎采集人群的石料开发策略、人群迁徙和交流联系.青海湖盆地151遗址出土的928件石制品的石料研究分析显示,处于末次冰消期的下文化层的石制品以近源的石英和石英岩为主要原料,而处于全新世早中期的上文化层在同类型近源石料仍占主体地位的情况下,开始出现较高比例和多样化的优质硅质石料,并且主要用于生产细石器.野外调查和查阅地质资料均未发现青海湖盆地内有151遗址中出现的同类型优质硅质石料产出,推测其来自远距离搬运.青海湖盆地内其他8个末次冰消期至全新世中期遗址的3269件石制品石料分析结果显示,与151遗址同类型的远源优质硅质石料在全新世早期开始在盆地内的遗址中出现.这一结果表明青海湖盆地末次冰消期古人类活动强度和范围有限,全新世早中期古人类受到全新世大暖期气候变好和周边地区农业人群兴起挤压活动空间的双重影响,在高原上的活动范围和强度大大增加,伴随着开始有意识地开发优质石料,较频繁地进行远距离迁移和人群交流.远源优质硅质石料的产地可能位于北祁连山区和青藏高原上的陆相火山岩区,需要未来更深入的研究揭示.该研究为深入理解青藏高原古人类的高海拔环境适应策略和移动模式提供了重要材料,为理解史前人类向高原扩散的机制提供了重要信息.  相似文献   

3.
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   

4.
Weathering of chert artifacts from three Lapita sites (ca. 3000–2000 B.P.) in the Southeast Solomons is examined. It is shown that the rate of weathering is strongly influenced by soil pH, mineralogy, and prehistoric burning of the material. The concentrations of some major elements (Na, Cl, K, Al) are shown to have been altered during the weathering process. Implications of this work for the sourcing and dating of cherts are discussed.  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.
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   

7.
Neolithic artifacts made of nephrite, □Ca2(Fe,Mg)5Si8O22(OH)2, are found at prehistoric settlements in Bulgaria. This study investigates these objects based on particle induced X‐ray emission using a scanning nuclear microprobe (micro‐PIXE technique). Seven nephrite artifacts from the Neolithic sites of Kovachevo, Bulgarchevo and Galabnik in southwest Bulgaria were analyzed to quantify their composition and to establish if a correlation exists between the distribution of major and trace elements, color, impurities, and texture. The nephrite artifacts are tremolite in composition, with a proposed ultrabasic origin. Based on the geochemical data obtained by micro‐PIXE, we divide the artifacts into Group 1 objects from the Kovachevo site and Group 2 objects from the Galabnik and Bulgarchevo sites. The analytical data and microprobe analyses are compared with geochemical data of nephrite from across the globe. The results are in a good agreement with previous electron microprobe and electron paramagnetic resonance (EPR) spectroscopy data. Our study provides a better understanding of the mineralogy and geochemistry of nephrite artifacts and helps to address questions regarding origin and the distribution of such materials in Bulgaria and other Balkan countries.  相似文献   

8.
《Sedimentary Geology》2006,183(3-4):203-216
This paper presents rare earth element (REE) geochemistry of siliceous deposits from which hydrothermal activity and basin evolution are elucidated, in the Late Devonian, in the Yangshuo basin, South China, where siliceous deposits widely occurred as nodular chert in the deep-water limestones and bedded chert interbeded with tuffaceous chert in the early Late Devonian. Both nodular and bedded cherts are characterized by very low La abundances (avg. 2.07 and 2.49 ppm, respectively), intermediate negative Ce anomalies (Ce/Ce*: avg. 0. 69 and 0.61), slight to intermediate positive Eu anomalies (Eu/Eu*: avg. 1.33 and 1.57), and low to intermediate shale-normalized Lan/Ybn values (avg. 0.86 and 0.52) and intermediate Lan/Cen values (avg. 1.61 and 1.72). These suggest both nodular and bedded cherts formed in the open marine basin of South China, rather than in the intracontinental rift basin as previously assumed, with involvement both with seawaters as indicated by intermediate negative Ce anomalies and generally LREE-depleted patterns, and hydrothermal vent fluids as indicated by convex, less LREE-depleted patterns with apparent positive Eu anomalies. In comparison with nodular and bedded chert, the tuffaceous chert has the highest La abundances (avg. 17.11 ppm), similar ranges of Ce anomalies (avg. 0.63) and Lan/Cen values (avg. 1.77), but lower Lan/Ybn values (avg. 0.48) and no apparent positive Eu anomalies (avg. 0.97). This suggests that the tuffaceous fallouts were also significantly modified by the hydrothermal fluid and seawater. Rapid spatial variations of Eu/Eu* values and degree of LREE-depletions in the studied basin are recognized, characterizing a spatially differential hydothermal activity that is not well discriminated by major element features. Such a difference in hydrothermal activity is interpreted as having been related to the intensity and depth of syndepositional tectonic activity, reconciling the structural pattern unraveled by stratigraphic packages.  相似文献   

9.
The Ediacaran–Cambrian transition was one of the most critical intervals in Earth history. During this interval, widespread chert was precipitated, commonly as a stratal wedge in carbonates, along the southern margin of the Yangtze Platform, South China. The chert wedge passes into a full chert succession further basinward to the south‐east. Four lithotypes of chert are identified across the marginal zone in western Hunan: mounded, vein, brecciated and bedded chert. The mounded chert is characterized by irregular to digitiform internal fabrics, generally with abundant original vesicles and/or channels that mostly are lined by botryoidal chalcedony cements with minor quartz and barite crystals. The host chert (or matrix) of these mounds is dominated by amorphous cryptocrystalline silica, commonly disseminated with pyrite. The vein chert, with minor quartz locally, generally cross‐cuts the overlying dolostone and chert horizons and terminates under the mounded and/or bedded chert bodies. The brecciated chert commonly occurs as splayed ‘intrusions’ or funnel‐shaped wedges and cross‐cuts the topmost dolostones. The bedded chert, the most common type, generally is thin to medium‐bedded and laminated locally; it is composed of amorphous silica with minor amounts of black lumps. Microthermometry of fluid inclusions from vein and void‐lining minerals (mainly quartz and barite) revealed homogenization temperatures from 120 to 180°C for the trapped primary fluids. Compositionally, these chert deposits generally are pure, with SiO2 > 92 wt%, and only minor Fe2O3 and Al2O3 contents, most of which show positive Europium anomalies in rare earth element patterns, especially for the mounded chert. All these data suggest that the marginal zone chert deposits resulted from a low‐temperature, silica‐rich hydrothermal system, in which the mounded chert was precipitated around the releasing vents, i.e. as silica chimneys. The vein and splayed brecciated chert, however, was formed along the syndepositional fault/fracture conduits that linked downward, while the bedded chert was precipitated in the quieter water column from the fallout of hydrothermal plumes onto the sea floor. These petrological and geochemical data provide compelling evidence and a new clue to the understanding of the extensive silica precipitation; rapid tectono‐depositional and oceanic changes during the Ediacaran–Cambrian transition in South China.  相似文献   

10.
Exposures of metamorphic basement in the Central Andes are scarce and reconstructions of the history of the Pacific margin of Gondwanaland must rely on a few isolated outcrops. We studied two areas of exposed basement in northernmost Chile (Belen) and westernmost Bolivia (Cerro Uyarani). The Belen metamorphic complex has been known for some time and consists of fault-bounded amphibolites, gneisses, schists, and minor quartzites overlain by folded Mesozoic to Cenozoic strata. The Cerro Uyarani is the only basement outcrop on the Bolivian Altiplano and has only recently been found and studied by geological reconnaissance. It consists of foliated mafic and felsic granulites, charnockites, and amphibolites. How do these basement occurrences compare and how do they relate to the other Precambrian crustal domains in the Central Andes? To answer these questions, we used geothermobarometers to reconstruct the P–T conditions of metamorphism, as well as geochemical analyses and petrological methods to study these rocks. The two basement blocks were found to have distinct geological histories and are probably separated by a major crustal domain boundary. Isotopic fingerprinting by Pb-isotopes clearly exclude Laurentian crustal components either in the protoliths or as reworked material. This signature is quite distinct from basement rocks farther south in Chile and northwestern Argentina.  相似文献   

11.
《Applied Geochemistry》2006,21(10):1635-1655
In order to interpret pre-historic cultural interactions, the provenance of amphibolitic raw material used for flat-axes and adzes in lower to middle Neolithic cultures throughout present day Germany were investigated by elemental and Sr, Pb isotopic methods. Within all settlements studied, a homogeneous actinolite-hornblende schist rock type (AHS) was found to be massively dominating, with a distinct petrography of needle-shaped actinolite interwoven with single larger grains of hornblende along with calcic plagioclase and large amounts of ilmenite. Geochemically, the AHS group is very homogeneous and has a signature of an enriched basaltic precursor with high concentrations of particularly the LIL-elements. The geochemical signature is relatively rare and can not be matched in nearby geological outcrops, wherefore the conclusion of “imported material” is quickly reached. Strontium and Pb isotopic analyses of the AHS were compared to the isotopic composition of amphibolitic rocks with similar petrography and trace elemental signatures within possible archaeological trade regions. The isotopic data of the archaeological material point roughly to a Proterozoic age of the stone used; an age which can be reasonable matched to a single outcrop situated at Jistebsko within the Czech Republic. This area further shows archaeological traces of prehistoric mining. Based on petrographic, geochemical and isotopic evidence, this area is here presented as the provenance area of the stone raw material, which later spread throughout prehistoric Europe – establishing contact and trade routes between Neolithic cultures.  相似文献   

12.
古玉产地溯源研究对揭示文明早期玉石资源开发利用和跨区域物质、文化交流等都具有重要的意义。由于测试分析手段及研究样品本身的制约,古玉产地溯源至今仍然是制约古玉文化交流研究的难题及瓶颈。近年来,随着研究的深入及科学测试手段的进步,地质、考古及文博界开展了更为密切的跨学科合作,对古代玉器产地溯源技术进行了许多新的探索,并取得了一些较为重要的成果。本文在团队工作及前人研究的基础上,对质子激发X射线荧光(PIXE)、X射线荧光光谱(XRF)、激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)、电子探针(EPMA)等多种主微量元素地球化学分析测试技术及放射性同位素、稳定同位素地球化学技术在古代玉器产地溯源的应用情况进行了梳理,综合分析了不同测试方法在古玉溯源中的工作进展,并对当前古玉产地溯源研究中存在的问题进行了探讨。总体来说,岩矿地球化学分析测试技术的应用对古玉溯源研究起到了重要的推动作用,而对已知玉矿资源系统的地质学研究及玉料的主微量元素、同位素地球化学数据库的建设和新的无损、样品尺寸不受限的原位岩矿地球化学分析技术的开发及其在古玉样品测试中的大规模应用,应是未来古玉溯源研究工作的重点方向。  相似文献   

13.
Geochemical composition (major and trace elements) of Miocene sandstones of the Surma Group exposed in Sitapahar anticline, Southeastern Bengal Basin was determined to reveal their provenance, tectonic setting and source area weathering conditions. The sandstones are sub-arkosic, sub-lithic and greywacke in composition with abundant low-grade metamorphic, sedimentary lithics (mainly chert with some shale fragments), low feldspars and little volcanic detritus. Compared to the average sandstone value, the Surma Group sandstones are depleted in CaO and enriched in Al2O3, Fe2O3 and Na2O. The Chemical Index of Alteration (CIA) values for the Miocene Surma Group sandstones vary from 57 to 73 with an average of 65, indicating low to moderate weathering of the source areas. The geochemical characteristics suggest an active continental margin to passive margin setting for the Surma Group sandstones; preserve the signatures of a recycled provenance that is agreement with sandstone petrography and derivation of these sandstones from felsic source rocks.  相似文献   

14.
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15.
Organic geochemical and petrological assessment of coals/coaly shales and fine grained sediments, coupled with organic geochemical analyses of oil samples, all from Permo–Triassic sections of the Southern Sydney Basin (Australia), have enabled identification of the source for the widely distributed oil shows and oil seeps in this region. The Permian coals have higher hydrogen indices, higher liptinite contents, and much higher total organic matter extract yields than the fine grained sediments. A variety of source specific parameters obtained from n-alkanes, regular isoprenoids, terpanes, steranes and diasteranes indicate that the oil shows and seeps were generated and expelled predominantly from higher plant derived organic matter deposited in oxic environments. The source and maturity related biomarkers and aromatic hydrocarbon distributions of the oils are similar to those of the coals. The oil-coal relationship also is demonstrated by similarities in the carbon isotopic composition of the total oils, coal extracts, and their individual n-alkanes. Extracts from the Permo–Triassic fine grained sediments, on the other hand, have organic geochemical signatures indicative of mixed terrestrial and prokaryotic organic matter deposited in suboxic environments, which are significantly different from both the oils and coal extracts. The molecular signatures indicating the presence of prokaryotic organic matter in some of the coal extracts and oils may be due to thin sections of possibly calcareous lithologies interbedded within the coal measures. The genetic relationship between the oils and coals provides new evidence for the generation and expulsion of oils from the Permian coals and raises the possibility for commercial oil accumulations in the Permian and Early Triassic sandstones, potentially in the deeper offshore part of the Sydney Basin.  相似文献   

16.
This work characterizes the source rock potential of the Tarfaya Basin and enabled us to reconstruct its geochemical history. Outcrop samples covering different stratigraphic intervals, plus the northwestern part of the Zag/Tindouf Basin (Bas Draa area), were analyzed for total organic carbon (Corg) and total inorganic carbon contents and total sulfur content. Rock-Eval analysis and vitrinite reflectance measurements were performed on 56 samples chosen on the basis Corg content. A set of 45 samples were extracted and non-aromatic hydrocarbons were analyzed by way of gas chromatography-flame ionization detection (GC-FID) and GC-mass spectrometry (GC-MS). Non-isothermal open system pyrolysis at different heating rates was applied to obtain kinetic parameters for modelling petroleum generation from four different source rocks.High quality petroleum source rocks with high Corg content and hydrogen index (HI) values were found for samples of Eocene, Coniacian, Turonian and Cenomanian age. Most samples were carbonate rich and organic/sulfur values were high to moderate. Various maturity parameters indicated immature or possibly early mature organic matter. Based on organic geochemical and petrological data, the organic matter is of marine/aquatic origin (Cenomanian) or a mixture of aquatic and terrigenous material (Eocene). The Early Cretaceous interval did not contain high quality source rocks, but indications of petroleum impregnation were found.  相似文献   

17.
通过1：50 000区域地质调查,发现云南省会泽县一带灯影组中普遍发育硅质岩。本文通过硅质岩岩石学特征和地球化学特征分析,重点探讨了灯影组各段硅质岩的成因机制和沉积环境。结果表明：震旦系-寒武系灯影组下段硅质岩中相对富集Al和Ti,总稀土（ΣREE）相对较高,Ce呈负异常,Eu呈正异常;中段硅质岩中相对富集Ca和Mg,总稀土较低,LREE>HREE,Ce呈负异常,Eu呈正异常;上段硅质岩总稀土较低,LREE>HREE,Ce大部分呈负异常,Eu呈正负异常。综合硅质岩岩石学、地球化学特征,并结合震旦纪区域地质构造演化,认为研究区内下段硅质岩表现为正常海水沉积、中段硅质岩表现为典型热水沉积、上段表现出正常海水沉积受热水沉积影响的特征。硅质岩形成于复杂大陆边缘的浅海陆棚环境。  相似文献   

18.
At least four volcanic complexes of different age and petrologic character occur in southeastern New England. Each complex contains a variety of fine-grained felsitic rocks, and three of these are known to have been quarried by prehistoric people for material used in the production of stone tools. These volcanics include a Late Proterozoic calcalkaline suite (Lynn-Mattapan) and several alkaline suites of Ordovician to Carboniferous age (Blue Hill, Spencer Hill, and Wamsutta suites). Each suite exhibits unique petrographic and geochemical features that help to constrain sources of felsitic archaeological materials. Distinctive petrographic features are: (1) Lynn/Mattapan: mostly pyroclastic rocks that typically contain broken crystals, volcanic clasts, and relict pumice and glass shards; phenocrysts of plagioclase, quartz, and perthite, commonly in glomeroporphyritic clusters; accessory sphene and prominent late-stage epidote; some varieties exhibit distinct flow-banding. (2) Blue Hill and Spencer Hill rocks: mainly lava flows; abundant perthite and quartz phenocrysts, with minor or no plagioclase; accessory minerals may include fluorite, aegerine, riebeckite, zircon, and allanite. (3) Wamsutta rhyolite: phenocrysts solely of anorthoclase; quartz restricted to late-stage filling of vesicles, and to planar, subparallel fractures in-filled as lithophysae; lava flows with devitrified glass matrix. Major element geochemistry is of limited use in distinguishing the volcanic groups, but trace element signatures are distinct and provide excellent criteria to discriminate rocks from each suite. Compared to the Lynn/Mattapan suite, the Blue Hill and Spencer Hill rocks exhibit higher concentrations of Rb, Y, Zr, Nb, La, Ce and Zn, and lower concentrations of Sr and Ba. Wamsutta rhyolite is intermediate in composition, but distinct. Examination of material from six prehistoric quarries, and debitage collected at seven archaeological sites, demonstrates that most samples can be assigned to one of the above volcanic suites based on combined petrographic and geochemical attributes. These geologic attributes add a significant element of quantification to archaeological sourcing problems that lead to improved identification of materials compared to hand sample characterization alone. The volcanics from source areas proximal to the Boston basin were important to Early and Middle Archaic period populations across most of southeastern Massachusetts. During the Late/Terminal Archaic period, these materials were being transported extensively throughout eastern and southeastern Massachusetts, the Narragansett Bay area, and parts of Rhode Island. Thus, routinely applied geological methods can provide useful approaches to constrain the sources of felsites from southeastern New England found in archaeological contexts. © 1997 John Wiley & Sons, Inc.  相似文献   

19.
Lithic artifacts consisting of celts, atlatls, pipes, knives, scrapers, and ceremonial placards were excavated from 54 archaeological sites throughout four counties of northeast Alabama. An analysis of mineralogy, texture, and structure of the lithic implements was employed. Samples were studied visually and microscopically by thin section. Rock samples indigenous to the study area were also examined and compared to the artifacts to determine similarities and differences. All artifacts analyzed were formed from meta-morphic rock types derived from outcrops ranging from less than 1 km to 60 km away from a respective archaeological site. Variance in mineralogy was notable; however, the most significant difference was in the texture and internal structure of the minerals within the artifacts. A total of 50 lithic samples were ultimately accepted as actual worked artifacts. Forty-one (82%) exhibit a texture, structure, and mineralogy indicative of the Hillabee (Greenstone Schist) Formation, while nine (18%) exhibit physical characteristics indicative of the Heflin Phyllite. Trade and migration routes with minimum distances to known outcrops hosting rocktypes most indicative of the artifacts collected from these prehistoric camps and villages are inferred. © 1993 John Wiley & Sons, Inc.  相似文献   

20.
Obsidian from the Coso locality, Inyo County, California, has long been regarded by archaeologists as a single “source.” However, studies by the U.S. Geological Survey have provided evidence of geochemical variability among flows within the volcanic field. to determine whether these geochemical distinctions could be applied productively to archaeological research, nondestructive x-ray fluorescence analyses were conducted on samples recently collected from 15 obsidian-bearing loci. the results of this research show that geochemically distinct varieties of artifact-quality obsidian can be recognized within the Coso volcanic field, and subsequent nondestructive x-ray fluorescence analyses of artifacts from two nearby archaeological sites document that different geochemical varieties of obsidian were used prehistorically to manufacture tools. Implications of these results for studies of prehistoric exchange and obsidian hydration dating are discussed.  相似文献   

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