5 resultados para Central Region [Thailand]

em Bucknell University Digital Commons - Pensilvania - USA


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The expansion of agriculture in the Near East during the middle Holocene significantly altered the physical landscape. However, the relationship between the scale of agriculture and the magnitude and timing of the environmental impacts is not well known. The Gordion Regional Survey provides a novel dataset to compare settlement density during archaeological periods to rates of environmental disruption. Sediment samples from alluvial cores directly date the environmental disruption, which can be matched to period-specific settlement intensities in the watershed as constructed from archaeological survey ceramics. Degradation rates rose sharply within a millennium of the earliest Chalcolithic occupation. Early Bronze Age (EBA) land use induced the greatest rates of environmental degradation, although settlement density was relatively low on the landscape. The degradation rate subsequently decreased to one-third its early peak by the Iron Age, even as settlement intensity climbed. This trajectory reveals how complex interaction effects can amplify or subdue the responses of the landscape-land use system. Prior to settlement, landscape soil reservoirs were highly vulnerable, easily tipped by early agricultural expansion. Subsequent reduced rates of erosion are tied both to changes in sociopolitical organization and to depletion of the vulnerable soil supply.

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Current understanding of the Iron Age polity of Phrygia in Central Anatolia is primarily based on excavations and survey in the region of the Phrygian capital of Gordion. In order to expand our knowledge of the Phrygian polity, we assess the scale and nature of Iron Age communities in the western (EskiAYehir) region of Phrygia. We address the challenge of interpreting ceramics derived from large-scale archaeological survey by utilizing Neutron Activation Analysis (NAA) of ceramics from 12 sites across the region collected by the EskiAYehir archaeological survey project as well as an excavated assemblage from Aar Hoyuk. While the uniformity in ceramic technology and styles suggest the region is part of the larger Phrygian community, NAA results reveal that (a) ceramic production was regionally highly localized with limited evidence of standardization during the Iron Age and (b) based on evidence of community interaction it is possible to establish a partial chronological sequence of development. These results have implications not only for understanding the internal dynamics within the Phrygian core but also for developing a methodology for comparing ancient polities using commensurate units of interacting communities. The present study is part of the larger Anatolian Iron Age Ceramics project (http://www.une.edu.au/a-ia).

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The study performs a panel estimation of the relationship between per capita income, trade, and airborne pollution in the five Central Asian nations, Russia and China between 1992 and 2008. First, this study uses an environmental Kuznets curve hypothesis (EKC)- an inverted-U relationship between the increase in income and the level of environmental degradation - to examine how income and pollution are related. Second, the study uses a gravity model to estimate the effect of a regional trade agreement (Shanghai Cooperation Organization: SCO) on incomes and carbon dioxide emissions in the region. Empirical analysis confirms the existence of the rising portion of the EKC curve in the region - a positive correlation between per capita income growth and carbon dioxide emissions- and that the volume of bilateral trade, and not the existence of a regional trade agreement, contributes to the increasing level of environmental pollution.

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The study performs a panel estimation of the relationship between per capita income, trade, and airborne pollution in the five Central Asian nations, Russia and China between 1992 and 2008. First, this study uses an environmental Kuznets curve hypothesis (EKC)- an inverted-U relationship between the increase in income and the level of environmental degradation - to examine how income and pollution are related. Second, the study uses a gravity model to estimate the effect of a regional trade agreement (Shanghai Cooperation Organization: SCO) on incomes and carbon dioxide emissions in the region. Empirical analysis confirms the existence of the rising portion of the EKC curve in the region - a positive correlation between per capita income growth and carbon dioxide emissions- and that the volume of bilateral trade, and not the existence of a regional trade agreement, contributes to the increasing level of environmental pollution.

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Detrital zircon and metamorphic monazite ages from the Picuris Mountains, north central New Mexico, were used to confirm the depositional age of the Marquenas Formation, to document the depositional age of the Vadito Group, and to constrain the timing of metamorphism and deformation in the region. Detrital zircon 207Pb/206Pb ages were obtained with the LA-MC-ICPMS from quartzites collected from the type locality of the Marquenas Formation exposed at Cerro de las Marquenas, and from the lower Vadito Group in the southern and eastern Picuris Mountains. The Marquenas Formation sample yields 113 concordant ages including a Mesoproterozoic age population with four grains ca. 1470 Ga, a broad Paleoproterozoic age peak at 1695 Ma, and minor Archean age populations. Data confirm recent findings of Mesoproterozoic detrital zircons reported by Jones et al. (2011), and show that the Marquenas Formation is the youngest lithostratigraphic unit in the Picuris Mountains. Paleoproterozoic and Archean detrital grains in the Marquenas Formation are likely derived from local recycled Vadito Group rocks and ca. 1.75 Ga plutonic complexes, and ca. 1.46 detrital zircons were most likely derived from exposed Mesoproterozoic plutons south of the Picuris. Ninety-five concordant grains from each of two Vadito Group quartzites yield relatively identical unimodal Paleoproterozoic age distributions, with peaks at 1713-1707 Ma. Eastern exposures of quartzite mapped as Marquenas Formation yield detrital zircon age patterns and metamorphic mineral assemblages that are nearly identical to the Vadito Group. On this basis, I tentatively assigned the easternmost quartzite to the Vadito Group. Zircon grains in all samples show low U/Th ratios, welldeveloped concentric zoning, and no evidence of metamorphic overgrowth events, consistent with an igneous origin. North-directed paleocurrent indicators, such as tangential crossbeds (Soegaard & Eriksson, 1986) and other primary sedimentary structures, are preserved in the Marquenas Formation quartzite. Together with pebble-toboulder metaconglomerates in the Marquenas, these observations suggest that this formation was deposited in a braided alluvial plain environment in response to syntectonic uplift to the south of the Picuris Mountains. Metamorphic monazite from two Vadito Group quartzite samples were analyzed with an electron microprobe (EMP). Elemental compositional variation with respect to Th and Y define core and rim domains in monazite grains, and show lower concentrations of Th (1.46-1.52 wt%) and Y (0.67 wt%) in the cores, and higher concentrations of Th (1.98 wt%) and Y (1.06 wt%) in the rims. Results show that Mesoproterozoic core and rim ages from five grains overlap within uncertainty, ranging from 1395-1469 Ma with an average age of 1444 Ma. This 1.44 Ga average age is the dominant timing of metamorphic monazite growth in the region, and represents the timing of metamorphism experienced by the region. An older 1630 Ma core observed in sample CD10-12 may be interpreted as a result of low temperature metamorphism in lower Vadito Group rocks due to heat from ca. 1.65 Ga granitic intrusions. Core ages ca. 1.5 Ga are likely due to a mixing age of two different age domains during analyses. Confirmed sedimentation at 1.48-1.45 Ga and documented mid-crustal regional metamorphism in northern New Mexico ca. 1.44-1.40 are likely associated with a Mesoproterozoic orogenic event.