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Selected AbstractsTHE ,LITTLE ICE AGE': RE-EVALUATION OF AN EVOLVING CONCEPTGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 1 2005JOHN A. MATTHEWS ABSTRACT. This review focuses on the development of the ,Little Ice Age' as a glaciological and climatic concept, and evaluates its current usefulness in the light of new data on the glacier and climatic variations of the last millennium and of the Holocene. ,Little Ice Age' glacierization occurred over about 650 years and can be defined most precisely in the European Alps (c. AD 1300,1950) when extended glaciers were larger than before or since. ,Little Ice Age' climate is defined as a shorter time interval of about 330 years (c. AD 1570,1900) when Northern Hemisphere summer temperatures (land areas north of 20°N) fell significantly below the AD 1961,1990 mean. This climatic definition overlaps the times when the Alpine glaciers attained their latest two highstands (AD 1650 and 1850). It is emphasized, however, that ,Little Ice Age' glacierization was highly dependent on winter precipitation and that ,Little Ice Age' climate was not simply a matter of summer temperatures. Both the glacier-centred and the climate-centred concepts necessarily encompass considerable spatial and temporal variability, which are investigated using maps of mean summer temperature variations over the Northern Hemisphere at 30-year intervals from AD 1571 to 1900. ,Little Ice Age'-type events occurred earlier in the Holocene as exemplified by at least seven glacier expansion episodes that have been identified in southern Norway. Such events provide a broader context and renewed relevance for the ,Little Ice Age', which may be viewed as a ,modern analogue' for the earlier events; and the likelihood that similar events will occur in the future has implications for climatic change in the twenty-first century. It is concluded that the concept of a ,Little Ice Age' will remain useful only by (1) continuing to incorporate the temporal and spatial complexities of glacier and climatic variations as they become better known, and (2) by reflecting improved understanding of the Earth-atmosphere-ocean system and its forcing factors through the interaction of palaeoclimatic reconstruction with climate modelling. [source] Residential mobility and resource use in the Chiribaya polity of southern Peru: strontium isotope analysis of archaeological tooth enamel and boneINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 6 2007K. J. Knudson Abstract The Chiribaya were a complex polity during the Andean Late Intermediate Period (c. AD 1000,1300) in the Ilo and Moquegua Valleys of southern Peru. Recent research has demonstrated that the Chiribaya polity was a señorío, a confederacy of economically specialised parcialidades. Here we test hypotheses regarding the movement of individuals and resources among the Chiribaya-affiliated sites of Chiribaya Alta, Chiribaya Baja, San Gerónimo and El Yaral, as well as from outside of the Ilo and Moquegua Valleys. Although archaeological human enamel and bone strontium isotope ratios from Chiribaya Baja and San Gerónimo cluster closely, there is a wider variety of strontium isotope ratios observed at Chiribaya Alta and El Yaral. This indicates that individuals buried in cemeteries at these sites had access to a wider variety of resources, and probably moved between different geological zones throughout their lifetimes. Copyright © 2007 John Wiley & Sons, Ltd. [source] Fresh insights into long-term changes in flora, vegetation, land use and soil erosion in the karstic environment of the Burren, western IrelandJOURNAL OF ECOLOGY, Issue 5 2009Ingo Feeser Summary 1. ,The study focuses on species-rich, upland, heathy vegetation with arctic-alpine floristic affinities and Sesleria grasslands in the karstic Burren region, western Ireland. The investigations aimed at reconstructing the long-term development of these high conservation-value communities and the role of farming in their formation and long-term survival. 2. ,The methods used included pollen analysis and 14C-dating of short monoliths and investigation of grykes (fissures in karstic limestone) for evidence of soil erosion. Special attention was paid to fossil, coprophilous fungal spores as indicators of local grazing. The strong local character of the pollen records facilitated identification of inter-site differences as well as regional patterns. It is shown that open pine woodland characterized the Cappanawalla uplands between c. 1500 BC and 500 BC. It is proposed that such woodlands, with floristic affinities to Scandinavian open pine woodlands on calcareous soils, provided a suitable environment for the present-day, open heath vegetation with species such as Dryas octopetala, Arctostaphylos uva-ursi, Geranium sanguineum and Empetrum nigrum. 3. ,Burning of vegetation as a management tool was important in the uplands over most of the last two millennia. Firing seems to have ceased with the onset of more intensive grazing regimes in the 18th century. 4. ,Synthesis. Upland palaeoarchives, derived from shallow peaty deposits, show that the upland Burren supported mainly plagioclimax Corylus -dominated woody vegetation and grasslands from c. 1500 BC (beginning of present record), until possibly as late as the 17th century AD. In the uplands of the north-western Burren, open, species-rich pinewoods with hazel dominated. The northern-arctic elements in the present-day upland flora survived clearances, involving initially Pinus sylvestris (c. 500 BC) and subsequently Corylus avellana (c. AD 1600). Colluvial material retrieved from grykes supports the idea of considerable soil loss occurring as late as the first and early 2nd millennium AD. The investigations highlight the potential of upland palaeoarchives, consisting of short sequences, for elucidating vegetation and land-use dynamics in karstic environments such as the Burren. [source] CORRESPONDENCE AND DISCRIMINANT ANALYSES OF SAND AND SAND TEMPER COMPOSITIONS, TONTO BASIN, ARIZONA,ARCHAEOMETRY, Issue 2 2000J. M. HEIDKE Geologists use petrographic modal analysis to relate fluvial sand composition to source rock composition, thus establishing provenance. Archaeologists seeking to establish provenance of sand temper in pottery can use similar petrographic methods, but their finer scale of investigation requires more precise statistical tools than those employed by geologists. A quantitative method for performing that task is presented. It utilizes correspondence analysis and discriminant analysis of logratio transformed point-count data to define petrofacies, or sand temper resource procurement zones. The procedure is illustrated with sand and sand-tempered sherd samples collected from the Tonto Basin, central Arizona; temporal trends in utilitarian ceramic production c. AD 100,1350 are reviewed. [source] 6000 years of forest dynamics in Suserup Skov, a seminatural Danish woodlandGLOBAL ECOLOGY, Issue 2 2000Gina E. Hannon Abstract 1The history of a forest stand over the last 6000 years has been reconstructed by studying pollen, macrofossils and charcoal from a small, wet hollow in Suserup Skov on the island of Sjælland in eastern Denmark. 2The earliest recorded forest was Tilia -dominated but contained an intimate mixture of many different tree species that included Acer campestre, A. platanoides, Alnus glutinosa, Betula pubescens, Corylus avellana, Frangula alnus, Fraxinus excelsior, Malus sylvestris, Populus tremula, Pinus sylvestris, Quercus robur, Q. petraea, Salix spp., Sorbus aucuparia, Tilia cordata and T. platyphyllos. The preserved fruits of T. platyphyllos confirm its hitherto doubtful status as a native member of the Danish flora. 3The present-day woodland developed after a period of intensive anthropogenic disturbance between , 600 bc and ad 900, during which time open canopy conditions prevailed at Suserup. Fagus sylvatica and Fraxinus excelsior are the dominant trees at present, together with some Quercus robur and Ulmus glabra.4,Charcoal was present in the sediments from most time periods except at the Ulmus decline. In the last 1000 years of the sequence , the period of Fagus dominance , charcoal counts were consistently low. 5Pinus sylvestris was a natural component of this primarily deciduous forest, and the last macrofossil find dates from c. ad 900. Macrofossil Pinus cone scales recorded c. ad 1800 originate from planted individuals. Prior to Fagus dominance, the forest had an open structure partly caused by frequent, low-intensity fires associated with the presence of Pinus sylvestris. 6The replacement of Tilia by Fagus in this forest was catalysed by human activity. If the forest had not been so disturbed, the rich diversity of trees would most probably have persisted up to the present time, with only a moderate-sized Fagus population. [source] METHODOLOGICAL DEVELOPMENTS IN THE LUMINESCENCE DATING OF BRICK FROM ENGLISH LATE-MEDIEVAL AND POST-MEDIEVAL BUILDINGS,ARCHAEOMETRY, Issue 4 2007I. K. BAILIFF Fired clay brick samples, obtained from a group of seven high-status late-medieval and post-medieval buildings in England ranging in age from c. ad 1390 to 1740, were dated by the luminescence method using an optically stimulated luminescence (OSL) technique. The results obtained indicate that, when applied to quartz extracted from brick, the technique is capable of producing dates that are in consistently good agreement with independent dating evidence for the buildings. For six samples taken from a group of four dating ,control' buildings the mean difference between the central values of luminescence and assigned ages was 5 ± 10 years (SD, n = 6). The methodology used is appropriate for application to other standing buildings in other temporal and geographic regions, and may be used with confidence where conventional dating methods are less certain. The study also examines the luminescence characteristics of quartz and the characteristics of the lithogenic radionuclides in brick samples and identifies various aspects related to the assessment of experimental uncertainty in testing the reliability of the method. [source] | |||||||||||||