首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The variation of electron spin resonance (ESR) signal intensities and thermoluminescence colour images (TLCIs) of quartz was investigated in the present study for various rocks and sediments in Japan, to discuss the possibilities of identifying the sediment provenance. The ESR signal intensity of the E1’ centre in the same grain size in granitic quartz varies from sample to sample, except for that in Quaternary samples of volcanic sediment, which is very low, close to the noise level. It was found that the diagram, ESR intensities of Al versus Ti-Li centre signal intensities, distinguish volcanic from the same grain size in granitic quartz as well as distinguish individual tephra from another. The TLCIs from volcanic quartz and some granitic quartz samples is almost red and that from the rest of granitic and metamudstone quartz is blue as results of TLCIs although the emission intensities are different. Our results suggest that examining the multiple-centre signal intensities of ESR and the TLCIs are effective to identify the source of quartz and to estimate the sediment provenance.  相似文献   

2.
A technique for establishing source provenance for pegmatite quartz artifacts was developed using a quarry sample from the Churchill River basin of northern Manitoba and Saskatchewan. Secondary ion mass spectrometry (SIMS) was used to quantify Ti, Ge, Th, and U trace element concentrations and Pb isotope ratios, coupled with qualitative visual characteristics to distinguish between pegmatite quartz from different archaeologically exploited sources in the Churchill River basin region. The technique was also applied to a small sample of quartz artifacts recovered from sites in and around the study area in a preliminary attempt to assign or rule out raw material provenance to characterized sources.  相似文献   

3.
We have examined the cathodoluminescence (CL) and induced thermoluminescence (TL) properties of chert collected from the Ozark Mountains area of the central United States. The cherts showed predominately orange CL with occasional blue CL. X-ray diffraction indicates that the amount of orange CL correlates closely with the abundance of carbonates within the chert. Previous studies have shown that macroquartz characteristically gives off a weak and transient blue CL. Thermoluminescence studies concentrated on the shape of the radiation induced TL glow curve. The results seem to indicate all of the cherts sampled fall into one of four glow curve categories. The TL categories correspond to quartz crystallinity as measured by X-ray diffraction, which is probably a reflection of quartz grain size. Application of these techniques is somewhat new to chert studies, but may provide a useful criterion in establishing the number of chert varieties or sourcing chert provenience locations for artefacts collected from archaeological sites. Calcite and dolomite are expected to leach from chert surfaces upon exposure to weathering agents, thus making CL a helpful tool for the detection of fake stone artefacts with fresh fracture surfaces. Quartz crystallinity is an important factor in determining chert cleavage characteristics and TL appears to be a useful measure of this property.  相似文献   

4.
Cathodoluminescence (CL) images of quartz grains in the Appin Quartzite from the aureole of the Ballachulish Igneous Complex (Scotland) reveal a textural complexity that we interpret in the light of published models of the evolution of the contact aureole. Five distinct generations of quartz can be discriminated in CL. The oldest of these is a dark luminescing mottled quartz (Type 1 quartz) that occurs in the centres of pre‐existing grains, in samples collected from 210 m to 0.1 m from the contact. Dark mottled quartz is interpreted to be unrecrystallized material and has a regional metamorphic CL spectral signature. The onset of contact metamorphism resulted in grain growth visible in CL as a series of fine‐scale alternating bands of bright and dark luminescing material (Type 2 quartz), which we attribute to infiltration of repeated pulses of small amounts of H2O along grain boundaries. Close to the intrusion, a subgrain‐scale network of intragranular, bright luminescing features could have resulted from either intragranular microcrack‐controlled infiltration of H2O at high temperatures or intergranular cracking followed by grain growth (Type 3 quartz). Broad bands of bright material on grain boundaries in samples that are inferred to have undergone partial melting are interpreted as quartz crystallized from the melt phase (Type 4 quartz). The final stage in the textural development is marked by a series of aligned fractures, detected in CL by nonluminescing material (Type 5 quartz) and corresponding closely with trails of fluid inclusions. These fractures are interpreted as the pathways for late‐stage, low‐temperature, retrogressive fluids.  相似文献   

5.
R. B. MASON 《Archaeometry》1995,37(2):307-321
The application of petrographic analysis to the problems of provenance attribution of ceramics made in the Islamic world is complicated by the presence of the highly quartzose ‘stonepaste’body. To facilitate the differentiation of different stonepaste groups, it has been necessary to develop specific criteria for distinguishing the characteristics of each centre, including the assessment of the degree of cloudiness of the quartz as rendered by fluid inclusions. This has enabled the successful application of petrographic analysis, and the solution of a number of provenance problems.  相似文献   

6.
Visual and geochemical analyses of 30 pre‐contact quartz tools from the Churchill River basin of northern Manitoba were used to provisionally assess source provenance based on comparison to local quartz quarry data. The results indicate that tools made from quartz acquired from these quarries were transported and eventually deposited into archaeological sites up to 200 km away. Transport of this quartz, which is of relatively moderate quality, over such distances suggests that stone tool–using hunter–gatherer populations that lived in the Churchill River basin of northern Manitoba were highly mobile. It also indicates that higher‐quality raw materials were unavailable in the immediate area.  相似文献   

7.
Ceramics are among the most important artifacts that archaeologists use to reconstruct patterns of prehistoric trade and exchange. Petrographic analysis of ceramic thin-sections, in addition to providing detailed technological data, enables the identification of sand-tempering agents. These raw materials are potentially important evidence for ceramic provenance, assuming that such common materials themselves would not have been traded. Here we apply methods developed by sedimentary petrographers to the problem of determining the provenance of Red Slipped sherds from late Prehistoric (c. AD 1000–1400) sites in the Caddoan area and contemporaneous Plains Village sites. Modal frequencies of different kinds of quartz, feldspars and lithic grains are used to construct several triangular graphs that reveal compositional patterns indicative of provenance. Sherds from the Plains Village sites exhibit higher frequencies of lithic grains, feldspars and polycrystalline quartz relative to the sherds from sites in eastern Texas and eastern Oklahoma. While anomalous sherds were identified, the longstanding assumption that Red Slipped sherds in Plains Village contexts were traded from the Caddoan area is not supported by these data. These methods have strong application potentials for other, geologically diverse portions of North America.  相似文献   

8.
横岭山商周时期玉器的质地、白化现象和玉料产地研究   总被引:1,自引:0,他引:1  
为研究广东博罗横岭山商周时期墓地出土玉器的质地、白化现象和玉料产地,对玉料样品进行常规矿物学、红外光谱、X射线粉晶衍射、扫描电镜和拉曼光谱的测试。结果显示,该墓地出土玉器的材质包括石英、水晶、透闪石(软玉)和杂砂岩。其中,透闪石质的玉器呈白色、不透明的外观,被认为和酸性土壤的腐蚀有关;出土的石英质玉器(含水晶器)的包裹体特征及包裹体均一温度显示该墓地出土的石英质玉器(含水晶器)的玉料较可能来自变质石英岩。伟晶岩或高温石英脉,将其与博罗本地、台山地区(近环珠江口地区)的石英及水晶样品进行对比,未有证据显示该墓地出土的石英质玉器(含水晶器)的原料来自上述地区。本研究可为揭示商周时期珠江三角洲地区的先民对自然资源的认识和利用能力以及当时社会的生产力水平、物品交换及贸易路线等方面提供基础科学依据。  相似文献   

9.
Ceramic provenance studies have helped archaeologists examine trade and exchange in multiple scales, the organization of production, and even vessel function. Yet, they may go even further, to provide a venue for the examination of past people’s perception of their landscape. To do so, a methodology is needed that links the choices prehistoric potters made, as reflected in their ceramics, with the choices their landscape could afford them, as reflected in the extent and distribution of local clays, and the physical, chemical and mineralogical characteristics of these clays. Using the region of Bova Marina in southwestern Calabria as a case study, we have combined a raw materials survey with field and laboratory experiments, along with chemical and mineralogical analyses of the collected sediments to understand the distribution and the physical, chemical and mineralogical variability of locally available clays and provide baseline data against which prehistoric ceramic materials from the region may be compared. We show that the local sediments can be divided into three major units, based on their macroscopic, mineralogical and chemical characteristics, that correspond well with the major geological units outcropping in the study area. While two of these units have internally consistent properties, the third is variable.  相似文献   

10.
The ESR dating method requires to describe the evolution of the ESR signal intensities vs. increasing gamma doses, then to extrapolate the equivalent dose of radiation received by the sample since its deposition using mathematical fitting. The function classically used to describe the growth curves of ESR aluminium signal in quartz was recently discussed and challenged for Lower Pleistocene sediments. In the present work, some alluvial sediments sampled in Upper Pleistocene fluvial terraces of the Yellow River system (China) permit us to test the application of another extrapolation function (linear + exponential) recently proposed for Lower Pleistocene sediments. The equivalent doses obtained here for the recent deposits of the Yellow River system and the corresponding ages are promising and indicate the potential of ESR to date quartz deposits from Upper Pleistocene times.  相似文献   

11.
A multi-technique characterization and a provenance study of the black pigment used in Cucuteni pottery painting (Neolithic age, Romania) were carried out. 127 Cucuteni shards were analyzed by Raman spectrometry. The main components of this pigment are pyrolusite and/or jacobsite. Hematite and quartz are frequent minor components and Ti oxides were seldom found. The manganiferous corpuscles discovered at Neam? county (eastern part of Romania) were the raw material of the Cucuteni black pigment. The Mn corpuscles were studied using XRD, Raman, FT-IR and Atomic Absorption Spectrometry. The main components are birnessite, goethite and frequently, quartz. Raw material was subjected to a temperature of 750 °C for 6 h and,once cooled, analyzed through Raman and FT-IR spectrometry. Pyrolusite, hematite and quartz were found in the heated powder sample.  相似文献   

12.
This study provides a preliminary systematic characterisation of OSL sensitivity, with respect to sediment history, of single grains of Australian quartz from a variety of source rocks and depositional contexts. Samples from two distinct lithologies and with relatively short modern sedimentary histories were compared in an examination of the influence of rock type on OSL sensitivity. Sediments derived from weathered sandstone were found to be brighter than those from metamorphosed schists, suggesting that sensitivity may be inherited from the source rock and its earlier sedimentary history. Secondly, quartz from the same source, but different modes of deposition, was compared to assess the effect on sensitivity of nature of exposure to light during the most recent bleaching event. Quartz grain sensitivity appears not to vary depending on the mode of sediment deposition, suggesting that the nature of exposure to light during deposition is less important in the sensitisation process. This study highlights the complexity and variety of natural sedimentary quartz, demonstrating the limitations of an investigation based solely on OSL sensitivity. Further systematic investigation into the physical, geological and geomorphological characteristics of sediments is proposed to better understand the mechanisms of luminescence sensitisation in quartz.  相似文献   

13.
In luminescence dating of sediments, Mayya et al. (2006) pointed out that at single grain level, the beta dose for quartz grains is heterogeneous. This heterogeneity arises due the fact that the total potassium in sediment is contributed by few feldspar grains with up to 11–14% stoichiometric potassium (Huntley and Baril, 1997). Beta particles have a range of ∼2 mm, which is comparable to grain sizes and inter-grain distances. This fact implies that the spatial fluctuation of beta emitters (K-feldspars) around individual quartz grains results in heterogeneous dose deposition. These fluctuations therefore, lead to an inherent spread in palaeodoses received by individual quartz grains.  相似文献   

14.
Cathodoluminescence (CL) of minerals such as quartz and zircon has been extensively studied to be used as an indicator for geodosimetry and geochronometry. There are, however, very few investigations on CL of other rock-forming minerals such as feldspars, regardless of their great scientific interest. This study has sought to clarify the effect of He+ ion implantation and electron irradiation on luminescent emissions by acquiring CL spectra from various types of feldspars including anorthoclase, amazonite and adularia. CL intensities of UV and blue emissions, assigned to Pb2+ and Ti4+ impurity centers respectively, decrease with an increase in radiation dose of He+ ion implantation and electron irradiation time. This may be due to decrease in the luminescence efficiencies by a change of the activation energy or a conversion of the emission center to a non-luminescent center due to an alteration of the energy state. Also, CL spectroscopy of the alkali feldspar revealed an in-crease in the blue and yellow emission intensity assigned to Al-O?-Al/Ti defect and radiation-induced defect centers with the radiation dose and the electron irradiation time. Taken together these results indicate that CL signal should be used for estimation of the α and β radiation doses from natural radionuclides that alkali feldspars have experienced.  相似文献   

15.
This study investigates diversity among ophiolite‐bearing sediments that were exploited for pottery production in Bronze Age Crete (c.3000–1200 bc ). The focus is on loose and consolidated formations of Upper Tertiary to Quaternary ages that contain some detrital products of Mesozoic ophiolitic source rocks. A literature review, geological fieldwork, sediment sampling and petrographic analysis are combined to identify the origin, the geographical distribution and the stratigraphic position of these ophiolitic sediments, and to assess regional diversity in their mineralogy and texture. The results provide insights into current archaeological problems regarding the provenance and production of ophiolite‐bearing pottery in Bronze Age Crete.  相似文献   

16.
This study assesses the use of the Tescan Integrated Mineral Analyser (TIMA) platform, which integrates scanning electron microscopy—energy dispersive spectroscopy (SEM-EDS) chemical analysis with mineral identification software, to quantitatively determine the mineralogical composition of sediments in archaeological research. Ten samples, spanning 50,000 years of sedimentation, were examined from archaeological excavation profiles in the Boodie Cave, Barrow Island, Western Australia. TIMA mineral abundance data show a gradual change from a polymineralogic quartz-rich assemblage from ~50–12 ka to a more simple carbonate-dominate assemblage from the terminal Pleistocene. This trend is consistent with a decreasing contribution of reworked terrestrial siliciclastic sediments derived from the mainland and an increase in carbonate sediments of marine derivation, as the exposed coastal plain become submerged during post-glacial sea-level rise. SEM-EDS analysis has also provided empirical data on cultural materials, mainly bone and shell fragments that similarly reflect the increasing contribution of marine fauna into the Holocene sediments. Particularly useful is the ability of mineral mapping function of the TIMA outputs to help distinguish 16 sub-units representing sections of the main nine stratigraphic units, including at least three contiguous midden events. The SEM-EDS data indicate that the redeposited sediments were derived from the overlying midden unit, with layering reflecting differential settling of mineral phases. This study demonstrates that automated mineralogy studies using TIMA can clearly aid the identification of provenance and processes within archaeological sediments and soils.  相似文献   

17.
This study investigates the potential of luminescence to date deposits from different fluvial sedimentary environments; namely point bar deposits, sandy and silty channel fills and floodplain sediments. Samples were taken from Holocene (<5 ka) terraces of the Lech and Danube rivers, for which independent age constraint is available through 14C ages, archaeological data and historical maps. OSL-ages were obtained using small aliquots of coarse grain quartz for the majority of samples. Two further samples were dated by the IRSL-signals of polymineral fine grain extracts, as no sufficient number of coarse grains could be extracted from these sediments. In order to detect and ac-count for incomplete bleaching, we used the decision process suggested by Bailey and Arnold [Statistical modelling of single grain quartz De distributions and an assessment of procedures for estimating burial dose. Quaternary Science Reviews 25, 2475–2502, 2006]. Although their model was designed for single grains of quartz, our study shows that it is also applicable to multiple grains of quartz, pro-vided that a low number of luminescent grains is present on one aliquot. Luminescence ages of point bar deposits and a sandy channel fill correspond most closely to the independent age control. In the floodplain, sand-striped floodplain channel deposits were incompletely bleached to a moderate degree, yielding ages with acceptable overestimations, while fine-grained floodplain deposits were worst bleached. One crevasse splay deposit was so severely incompletely bleached that none of the age models was able to yield accurate ages.  相似文献   

18.
Changes in the grain-size distribution and the lithologi-cal I mineralogical properties of sandy-gravel sediments are used to discriminate between sources for the alluvial valley-fill of Bella Coola River, coastal British Columbia. Spatially variable bedrock sources, ranging from highly resistant quartz monzonites to easily weathered basalts, yield sediments that reflect parent rock characteristics. Local increases in the D95 fraction of bulk gravel samples and the D50 fraction of sand samples can be related to inputs from steeper, heavily glaciated tributaries, or those underlain by fractured basalts of the Fraser Plateau. Where there are similarities in the grain-size properties of the source and the sampled deposit, however, grain-size information alone cannot be used to discriminate between sources. The lithology of Bella Coola alluvium shows a close correspondence with the general distribution of rock types in the basin, suggesting proportional contributions from most tributary sources over the long term. However, sand samples from the floodplain have a mostly volcanic affinity, indicating the dominance of sediment derived from headwater tributaries underlain by this rock type. Admixture of plutonic source sediments is evident in lower Bella Coola River adjacent to alluvial fans, heavily glaciated tributary creeks or rock walls comprised mainly of quartz monzonite. Les changements dans la granulometrie et les proprietes lithologiques et mineralogiques des sediments de gravel sablonneux servent d differencier les sources des depéts alluviaux de la Riviere Bella Coola sur la céte de la Colombie-Britannique. La variation spatiale des sources fondamentales donnent des sediments qui refletent les caracteristiques de la roche-mbe variant des quartz rnonzonites très résistants aux basaltes superficiellement altérés par les agents atmospheriques. Les augmentations locales dans la fraction D95 des echantillons de gravel et la fraction D50 des echantillons de sable peuvent être reliees la contribution des tributaires aux pentes plus escarpees et fortement glaciaires ou ceux qui traversent les basaltes fractures du Plateau Fraser. Cependant, quand il y a des similitudes dans la granulometrie de la source et le dépôt-échantillon, l'information granulometrique seule ne peut pas 6tre employee pour differencier les sources. La lithologie des alluvions de Bella Coola montre une correspondance avec la distribution générale des types de roches dans le bassin, suggérant des contributions proportionnelles des sources tributaires a long terme. Cependant, les échantillons de sable des plaines sujettes à inondations ont en grande part une affinité volcanique, indiquant que la dominance du sédiment provient des tributaires qui traversent ce type de roche. Une addition de sediments de sources plutonique est evidente dans le bas de la Riviere Bella Coola adjacent aux eventails alluviaux, aux ruisseaux tributaires affect& par une forte glaciation, ou aux murs de roches qui comprennent principalement des quartz monzonites.  相似文献   

19.
C. H. LEE    J. KIM  M. S. LEE 《Archaeometry》2010,52(1):31-44
This paper presents material characteristics and raw material provenance of the stone moulds for bronze slender daggers from Galdong. This type of bronze dagger is uniquely distributed in the Korean Peninsula and these stone moulds were the first to be found by excavation. The stone moulds were made of igneous hornblendite with course-grained holocrystalline textures. Based on petrological, mineralogical and geochemical characteristics, the original rock materials of the moulds were inferred to be derived from the Jangsu or Namwon areas which are about 50 km away from the excavation site. It is a notable achievement that this provenance study confirmed the domestic production of Korean-styled daggers.  相似文献   

20.
A. G. WINTLE 《Archaeometry》2008,50(2):276-312
Luminescence techniques for dating both heated materials (e.g., pottery and burnt stone) and sediments have gone through three phases in the past 50 years. The first 22 years, from 1957 to 1979, were devoted to thermoluminescence (TL) techniques applied to heated material. In the next six years, from 1979 to 1985, it was found that TL dating could be applied to sediments. However, the TL signals of both quartz and feldspar grains observed for modern sediments were small, but were not zero, thus making them useful only for older sediments. A new luminescence signal that was totally zeroed by exposure to sunlight for a relatively short period of time, a few hours or less, was found; this led to the development of optically stimulated luminescence (OSL) dating techniques in 1985. Further developments have continued to the present day. Within the past 22 years, 1999 was also a year with major developments. A reliable procedure for single aliquots of quartz that have a rapidly bleached (‘fast’) OSL component was formalized and an instrument that allowed rapid measurement of equivalent doses for single grains was constructed. These developments have led to OSL becoming a major dating tool in Quaternary geology, at least for the past 100 000 years, and in archaeology, particularly as related to the dispersal of modern humans.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号