Building cultural chronology in Eastern Washington: The influence of geochronology,index fossils,and radiocarbon dating

Until the early 1950s, it was believed that the archaeological record of eastern Washington state did not exceed 4000 years. That belief changed in the middle 1950s after discovery of the Lind Coulee site (45GR97), originally dated to the Holocene on the basis of geochronological data and subsequently dated via radiocarbon to 8700 B.P. Geochronology and geoarchaeology provided temporal control and resulted in archaeological time being measured discontinuously as stratigraphically associated sets of artifacts were stacked one upon the other. Percentage stratigraphy and frequency seriation played no role in the measurement of time or the construction of cultural chronologies. Local cultural chronologies originally constructed on the basis of chronostratigraphic marker horizons were not significantly altered in the 1960s and 1970s because few radiocarbon ages were run and the chronological validity of the ages was questioned. The increased intensity of cultural resource management in the 1980s witnessed a marked increased in the production of radiocarbon ages, but extant cultural chronologies have not been significantly altered in structure or appearance. © 2000 John Wiley & Sons, Inc.     

Applications of molecular fossils in lacustrine stratigraphy

Biomarkers, or the so-called molecular fossils, are used tentatively in the Eogene lacustrine stratigraphy study in the Jiyang Sub-basin. Notwithstanding the fact that unidentified microfossils or amorphism and acritarchae are widely distributed in lacustrine source rocks, molecular fossils are useful to identify the sources. It is helpful to reconstruct the palaeo-enviroment, palaeo-ecosystem and compartmentalize the stratigraphic sequence by using molecular fossils with which the existence and types of microbes including bacteria, archaea and certain algae can be identified.     

The last deglaciation of the Norwegian Channel – geomorphology,stratigraphy and radiocarbon dating

Based on high‐resolution TOPAS acoustic data, bathymetric data sets and sediment cores from the Norwegian Channel, the last retreat of the Norwegian Channel Ice Stream has been investigated. Mapping of ice‐marginal features such as grounding‐zone wedges and terminal moraines off western Norway suggest that the retreat of the grounding line in this part of the channel was interrupted by frequent stillstands, whereas the channel south of the threshold at Jæren does not have crossing ice‐marginal landforms. Three main seismic units have been identified, and, based on their seismic characteristics, in addition to study of sediment cores, these units are interpreted as till (U1), glacial marine sediment (U2) and Holocene hemipelagic sediment (U3). Based on new and published radiocarbon dates of the lower part of U2, combined with dates from the adjacent areas, it is concluded that the grounding line started to retreat from the shelf edge at about 19 ka and that the inner part of Skagerrak was ice free at 17.6 ka. This gives an average retreat rate of 450 m a⁻¹, which is generally higher than mean retreat rates estimated for other palaeo‐ice streams (15–310 m a⁻¹).     

Archaeomagnetic dating of seven archaeological fireplaces in the Netherlands

The palaeomagnetic directions of seven Dutch fireplaces are compared with the archaeological age estimates which range from the first to the 17^th century AD. A comparison with the British master curve of secular variation for archaeomagnetic dating results in a refinement of the archaeological age estimates in two cases, while four other archaeological age estimates can be confirmed. For one fireplace only one sample is reliable, resulting in a very poorly defined archaeomagnetic age of 2 to 3 centuries younger than the expected age (i.e. late Middle Ages). On the other hand, accepting the archaeological age estimates, the palaeomagnetic directions can contribute to the database that is used to construct the British secular-variation master curve. We applied the classification grades proposed by Tarling & Dobson (1995) which range from unreliable (grade 1) to reliable (grade 5). Three fireplaces have grades 5, one has grade 4, one grade 3, one grade 1 and for one case no grade was assigned.     

Aeolian stratigraphy and thermoluminescence dating of sediments of late Holocene age from Sola, southwest Norway

Thermoluminescence age determinations were performed on four aeolian sand samples of late Holocene scenceagesediments from Stavanger airport, Sola, in southwest Norway. The locality is well suited for testing thermoluminescence dating because of a good agreement between radiocarbon ages and age information based on archaeological typology and sea level changes. The conclusion from a comparison of thermoluminescence and archaeologicaltypologyradiocarbon dates is that it is possible to date well bleached sediments as young as 1600 years with thermoluminescence (TL). The TL dates for the aeolian deposits are in accord with expected ages. Six formal, diachronous aeolian/non-aeolian phases are defined and grouped together as the Sola Episode. The first phase onousaeolian/non-aeolianof aeolian activity was short-lasting and took place in the middle Subboreal chronozone. A second and lianactivitywaslong-lasting period, dominated by aeolian activity, took place from the transition between the Subboreal and Subatlantic chronozones until the present. We conclude that human activities were the releasing factor for the aeolian activity recorded in sand sheets.     

中国早中更新世古人类遗址年代学研究中两种同位素测年方法的应用与思考

中国早中更新世人类遗址的发现对研究东亚地区早期人类的生存与演化具有重要意义,但这一时段的遗址已超出或接近¹⁴C、光释光和铀系等常用同位素测年方法的极限。电子自旋共振/铀系(ESR/U系)联合化石测年和宇宙成因核素²⁶Al/¹⁰Be埋藏测年是目前为数不多的能同时对早中更新世遗址地点进行年代学研究的两种同位素测年方法,优势在于可以直接对被关注的考古遗存(如文化层内的动物化石或石英质砾石石制品)进行测年分析,避免了由于测年对象与考古遗存之间地层关系的不明确给测年结果带来不确定性。本文以云南元谋人、北京周口店第一地点、湖北白龙洞和山东沂源人遗址为例,介绍了ESR/U系法和²⁶Al/¹⁰ Be埋藏测年法在上述早期遗址年代学研究中的应用,并探讨了两种方法存在的局限性。对于洞穴遗址的ESR/U系联合测年,化石年龄的不确定性主要来自于对化石外部剂量率的重建,需要化石有较明确的出土层位;而²⁶Al/¹⁰Be埋藏测年需要解决来自于被测沉积物或石制品可能存在的复杂埋藏历史对测年结果的影响。ESR/U系联合化石测年和等时线²⁶Al/¹⁰Be埋藏测年方法是目前最可行的早期遗址测年技术手段,在动物群化石组合和磁性地层学等间接测年方法给出的时间框架下,通过上述两种同位素测年方法可以为研究东亚早期人类活动提供更为精细的年代。

     

Palaeomagnetic dating and stratigraphy of a Cainozoic lake near Cooma,N.S.W.

Palaeomagnetic dates for two sites on the Southern Tablelands of New South Wales, at Bunyan and Bredbo, indicate that basal lake sediments and underlying bedrock were ferruginised during the late Tertiary. The dates provide further evidence of a regional episode of intense weathering and ferruginisation in the late Tertiary.     

High‐resolution stratigraphy of Scandinavian coastal archaeological settlements: the case of Håkonshella,W Norway

The stratigraphy of Scandinavian open‐air archaeological settlements is usually characterized as homogeneous, highly enriched in decomposing organic matter and poor in biogenic carbonates such as shells or bones. As a result, stratigraphies are often difficult to read in the field and settlement sequences may pass unnoticed by archaeologists. Here we show how the integration of bulk analyses, soil micromorphology, X‐ray fluorescence (XRF) core scanning and multivariate statistics can help in overcoming such limitations. We use the case study of Håkonshella 8, a Mesolithic hunter‐fisher‐gatherer settlement located in Bergen (W Norway). Fluctuations in the organic matter content, geochemical proxies (mainly P, Ga, Ti and the Si/Al ratio) and redoximorphic features highlight four cycles of site occupation and abandonment in an otherwise massive anthropogenic deposit. Following these settlement sequences, the site was covered by colluvium from nearby slopes over which a waterlogged soil formed. The approach used in Håkonshella has the potential to improve our capacity to interpret organically enriched anthropic deposits formed in coastal Scandinavia and in similar climatic regions.     

Neutron activation analysis of Mediterranean volcanic rocks – An analytical database for archaeological stratigraphy

Pumice has been used as a serviceable abrasive or religious artifact since antiquity and has therefore been an object of trade. By analyzing pumice samples from archaeological excavations and comparing the results to an analytical database, it is possible to establish the origin of the sample and thereby get information on the maximum age and the transport route of the pumice sample. In addition, the deposition of primary tephra deposits can be used as time markers, and place constraints on the ages of archaeological materials.Neutron activation analysis (NAA) was applied to determine the concentrations of 25 elements (As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb, Zn and Zr) in pumice samples from the Mediterranean region: Milos, Santorini, Kos, Giali and Nisyros (Greece), Lipari (Italy) and Cappadokia (Turkey). It was found that eruption products like pumice or volcanic ash can be correlated in many cases to their volcanic sources by comparison of the typical main- and trace-elemental concentration patterns (“chemical fingerprint”). Such a distinction is possible if the volcanic rocks are homogenous enough with respect to the concentrations of geochemically relevant elements. Using only the pure glass fraction of tephra, a sample size of 5 mg is sufficient for identification by NAA.     

The sedimentology,stratigraphy and 14C dating of a turf‐banked solifluction lobe: evidence for Holocene slope instability at Okstindan,northern Norway

The stratigraphy of a trench excavated through a solifluction lobe lying at an altitude of 860 m a.s.l. on the eastern flank of the Okstindan mountains is described. Sedimentological evidence suggests that the movement was probably dominated by a flow process, with silty sands episodically bursting‐out through a thinly vegetated lobe front in the spring and early summer thaw phases, when pore‐water pressures were likely to be increased. A continuous buried soil extends for some 14 m. Fourteen new radiocarbon age estimates from thin‐slice samples of this buried soil and organic fractions derived from laboratory pre‐treatment procedures are discussed. These data indicate that the solifluction probably commenced in the mid‐Holocene and continued throughout the Neoglacial. The slope instability may be correlated tentatively with the record of glacial variations, shifts in tree lines and archaeological evidence, supporting a link with regional climatic deterioration. Copyright © 1999 John Wiley & Sons, Ltd.     

Carbonates, granulometry, and color of tills on the south-central Canadian Shield and their implications for stratigraphy and radiocarbon dating

Till containing over 10% matrix carbonate extends in a belt 200–300 km wide south of the Hudson Bay Paleozoic basin source. The southern boundary is represented by the 'carbonate line', extending from Wawa to near Timmins and Cochrane in the study area. Higher silt content and lighter color are associated with the higher carbonate till. The carbonate tine corresponds approximately to the Chapleau moraine and correlative moraines to the northwest and may signify a discrete stratigraphic unit (possibly identifiable with the Matheson Till) formed by a glacial readvance. Glaciolacustrine sediments have higher carbonate content than nearby till and similarly form widespread sediment blankets even beyond that of the carbonate-rich till. Radiocarbon dating of amorphous organic sediments may be at risk because of old carbon error on such terrain and there may be some risk even in areas of much smaller carbonate content. A greater effort should be made to establish chronologies based on terrestrial plant matter, now more often possible with AMS radiocarbon dating.     

Shallow site archaeology: Artifact dispersal,stratigraphy, and radiocarbon dating at the Barger Gulch locality B Folsom Site,Middle Park,Colorado

Shallowly buried archaeological sites are particularly susceptible to surface and subsurface disturbance processes. Yet, because cultural deposition often operates on short time scales relative to geologic deposition, vertical artifact distributions can be used to clarify questions of site formation. In particular, patterns in artifact distributions that cannot be explained by occupation histories must be explained by natural processes that have affected sites. Buried only 10–50 cm beneath the ground surface for 10,450 ¹⁴C yr, the Folsom component at Barger Gulch Locality B (Middle Park, Colorado) exhibits many signs of post‐depositional disturbance. Through examination of variation in the vertical distribution of the artifact assemblage, we are able to establish that only a Folsom component is present. Using vertical artifact distributions, stratigraphy, and radiocarbon dating, we are able to reconstruct the series of events that have impacted the site. The Folsom occupation (˜10,450 ¹⁴C yr B.P.) was likely initially buried in a late‐Pleistocene eolian silt loam. Erosion brought the artifacts to rest on a deflation surface at some time prior to 9400 ¹⁴C yr B.P. A mollic epipedon formed in sediments that accumulated between 9400 and 7000 ¹⁴C yr B.P. Some time after 5200 ¹⁴C yr B.P., this soil was partially truncated, and artifacts that had previously dispersed upward created a secondary lag at its upper contact. This surface was buried again and artifact dispersal continued. © 2005 Wiley Periodicals, Inc.     

Lateglacial and early Holocene lake sediments from the northern Apennines, Italy – pollen stratigraphy and radiocarbon dating

Radiocarbon-dated pollen profiles are presented from two basins in Prato Spilla, near Val Parma in the northern Apennines. One basin contains a complete Holocene succession, the other a full Lateglacial to mid-Holocene record. The data provide the most comprehensive Lateglacial-early Holocene pollenstratigraphic succession yet reported from the northern Apennines accompanied by an internally consistent radiocarbon chronology. They provide fresh impetus for (a) a discussion of the strength of the Younger Dryas 'signal' in pollen-stratigraphic profiles from southern Europe, (b) an assessment of the palaeovegetation of northern Italy during the last glacial-interglacial transition, and (c) the altitude of the snowline in the region during the Younger Dryas.     

Trace fossils and ichnofabrics on the Lower Muschelkalk carbonate ramp (Triassic) of Germany: tool for high-resolution sequence stratigraphy

In the German Triassic of Thuringia, the Lower Muschelkalk sequence can be subdivided by application of ichnological methods. Three ichnofacies with five ichnofabrics are described. In accordance with the lithological features, trace fossils are found to defining parasequences on the basis of a regular change of bioturbation. Furthermore, it is possible to establish deepening-upward cycles. The reconstruction of parasequences allows the establishment of a high-resolution sequence stratigraphy. The position of the maximum flooding surface can be identified in the Terebratula Member and is developed in a condensed interval. The most significant of the additional major marine flooding surfaces is found at the top of the Upper Oolith Bed, characterized by lithostratigraphy, ichnology, biostratigraphy and parasequence thickness trends.     

Optical and thermoluminescence dating of Middle Stone Age and Kintampo bearing sediments at Birimi,a multi-component archaeological site in Ghana

We report the first luminescence ages for the archeological and geological sediments forming the substrate of the Birimi archaeological site in the Northern Region of Ghana. The site's significance rests on the fact that it contains a rich collection of artifact assemblages representative of three distinct cultures, and that, on the basis of artifact typology, the earliest assemblage is diagnostic of the Middle Stone Age (MSA). In situ occurrences of MSA artifacts are found at over 1 m below today's surface. They are overlain by a ceramic-rich complex of a sedentary or semi-sendentary Later Stone Age culture known as the Kintampo. The western half of the site is dominated by the industrial remains of Iron Age smelting activity.Elemental, mineralogical, and sedimentological analysis of the cultural and sub-cultural sedimentary horizons at the site revealed at least three distinct lithostratigraphic units. The quartz sediments are derived from the sandstone of the Gambaga escarpment, mass wasted and accreted fluvially at a rate of 3.2 cm/ka, forming a wide terrace at Birimi. Silts and finer fractions derive from windblown dust, likely from White Volta River and granitic sources to the north. Soil forming processes and wide fluctuations in moisture have progressively reduced the sediments at depth to the resistant quartz and kaolinite, with rich iron oxide coatings, and created two ironstone horizons composed of goethite-cemented quartz nodules.Multiple aliquot green-light stimulated optical ages for 125–150 μm quartz grains yielded ages of 23.6±2.9 and 40.8±11.8 ka for the MSA-bearing sediments, and 58.4±15.3 ka for the base of the terrace. Radiocarbon ages on charcoal from Kintampo-bearing units are 3.36–3.83 ka cal BP, and are supported by thermoluminescence (TL) ages on pottery sherds and burnt house daub fragments of this cultural complex. A 0.4 ka age on sediment from the site's surface confirms that the quartz zeroes well when exposed to natural light. Sediments bearing the Kintampo artifacts, however, yielded ages of 7.8–16.9 ka. These ages were obtained on sediments from large pits, some over 50 cm deep, and they deviate only slightly from the ages expected for naturally aggraded sediments at these depths. We conclude, therefore, that extensive digging of pits by the Kintampo dwellers was followed by rapid refilling, and that the bulk mobilization of the matrix did not permit the sedimentary quartz grains to experience any appreciable zeroing at that time.     

西藏日松乡一带发现早白垩世标准化石及其意义

研究区位于西藏阿里日松乡一带。岩性组合、沉积环境、古生物特征的详细研究为该地区中生代地层的时代归属提供依据。在日松乡日买栋纳一带原1∶25万日土县幅侏罗系中发现了大量扁平古圆笠虫和小星准柱珊瑚等早白垩世标准化石,这些化石的发现对研究区地层的时代归属提供了强有力证据。结合地层的初步沉积环境分析可知研究区早白垩世为残余海盆地沉积阶段。