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41.
The Primary Lower Gypsum in the Mediterranean: A new facies interpretation for the first stage of the Messinian salinity crisis 总被引:1,自引:0,他引:1
Lugli Stefano Manzi Vinicio Schreiber B. Charlotte 《Palaeogeography, Palaeoclimatology, Palaeoecology》2010,297(1):83-255
The detailed facies and physical stratigraphic analysis of the Primary Lower Gypsum in the Mediterranean indicates a surprising bed-by-bed correlation at basin-scale (Spain, Italy, Hellenic arc and Cyprus arc), that is tuned to the orbital calibration for the first stage of the Messinian salinity crisis from 5.96 to 5.61 Ma ago. A total of 16, precessionally-controlled, gypsum cycles were deposited rapidly in less than 350 ka, forming sequences up to 300 m thick. The lack of subaerial exposure features and the common facies associations and stacking pattern for sections located thousands of kilometers apart in different geological settings indicates a modest depositional depth, not extremely shallow. Selenite deposition occurred only at the bottom of restricted marginal basins less than 200 m deep, while no gypsum could precipitate in the deeper euxinic Mediterranean portions where only thin and barren shale/dolostone couplets formed. The lowermost selenite beds pass laterally to dolomite-rich limestones interbedded with barren euxinic shales in poorly oxygenated settings, indicating that the gypsum sedimentation was diachronous and did not necessarily mark the onset on the Messinian salinity crisis.Evaporite facies sequences (EF1 to 8) within individual gypsum beds show small-scale, subaqueous sedimentary cycles that mimic regressive-transgressive cycles: a) initial evaporite precipitation at relatively low supersaturation produced the massive selenite (facies EF3) in a relatively deep setting; b) continuous evaporation and drawdown by oscillating brine level formed the banded selenite (EF4) at the aridity acme of the precessionally-controlled cycle; c) general progressive brine level rise with strong brine flow led to the formation of large selenite supercones branching laterally (supercones in Spain and branching selenite, EF5, in the rest of the Mediterranean); and d) flooding by undersaturated continental water terminated gypsum precipitation with the deposition of argillaceous sediments (EF1, Northern Apennines), and/or limestone (EF2, Sicily and Spain) during the humid phase in the precession climate cycle.The stacking pattern and selenite facies associations suggest an overall shallowing-upward trend with a basin-wide hydrologic change starting from the 6th cycle (5.84 Ma), which is marked by the appearance of the branching selenite facies (supercones) in Spain and indicates that the brines became current-dominated. The Sr-isotope stratigraphy suggests that in the Northern Apennines the brines were strongly modified by continental waters (87Sr/86Sr = 0.708893 to 0.708998), and received direct pulses of Atlantic seawater (87Sr/86Sr = 0.70900 to 0.709024) only in the upper part of the section. In areas away from the mainland, such as Sicily, the continental input was by far less important. 相似文献
42.
Heitor Cantarella Jean Felipe Leal Silva Luiz Augusto Horta Nogueira Rubens Maciel Filho Raffaella Rossetto Tomas Ekbom Glaucia Mendes Souza Franziska Mueller-Langer 《Global Change Biology Bioenergy》2023,15(10):1190-1203
This Opinion highlights several successful cases of biofuel technologies recently described by the IEA Bioenergy Intertask Report on Lessons Learned. The report discussed the potential of biofuels to contribute to a significant market supply, thus replacing fossil fuels and mitigating global warming, and it underscores the challenges in expanding biofuel production and replicating successful models between countries and regions. Based on the lessons learned from conventional, established technologies, the authors analyzed policies, feedstocks, products, technologies, economics, environmental concerns, social aspects, scalability, and ease of implementation and replication in different countries or regions. There are blending mandates in place around the world to foster the use of biofuels. Dependence on the availability and price fluctuations of crop feedstocks may limit biofuel production in certain circumstances. Legal restrictions on using food crops as feedstocks present obstacles to scaling up production. Temporary constraints related to feedstock costs and availability, as evidenced by changes and postponements of biofuel blending mandates in various countries (particularly during the COVID-19 pandemic) also pose challenges. Technological hurdles exist for advanced biofuels that implicate premium pricing. Still, 2G ethanol from sugarcane meets very strict feedstock requirements with a carbon footprint so low that only electric vehicles charged in Norway could have life-cycle GHG emissions at the same level as a 2G ethanol-fueled combustion engine car. The authors evaluate whether and how much electrification could contribute to advance the decarbonization efforts in different countries. Drawing from these observations, the authors express their viewpoints to assist researchers and policymakers in the energy sector in formulating viable approaches to combat the climate crisis. 相似文献
43.
Aim Our aims were: (1) to reconstruct the phylogenetic relationships of daffodils (Narcissus), focusing on the lowland subgenus Hermione and the mountain section Apodanthi; (2) to estimate the temporal setting of diversification; (3) to reconstruct the migration patterns of the lineages; and (4) to examine the microevolutionary differentiation of the wide‐ranging Narcissus tazetta group across the Mediterranean. Location The Mediterranean Basin. Methods Plastid (trnT–L, trnL–F and ndhF) sequences were obtained from 63 populations representing 23 species of Narcissus and combined with published data from 16 species. Phylogenetic relationships and dating were inferred by Bayesian analysis based on geological events and divergence estimates of closely related taxa. A dispersal–extinction–cladogenesis analysis was performed using maximum likelihood methods to infer ancestral geographical distributions, and phylogeographical reconstruction was performed using coalescence analysis. Results Subgenus Hermione is not recognized as a monophyletic group because two of the nine species were found to have a close relationship with the subgenus Narcissus. The results on section Apodanthi confirmed previous findings of its monophyly and phylogenetic relationships within this mountain group. Molecular dating and ancestral range reconstructions suggest that the ancestor of Narcissus originated in the Iberian Peninsula during the Late Oligocene–Early Miocene. Eastward expansion of the lineage range proceeded from the western Mediterranean and involved colonization of mountain ranges in northern Africa. The phylogeography of the N. tazetta group revealed a widespread distribution of certain haplotypes, suggesting wide dispersal and a high level of colonization in the Mediterranean Basin. Main conclusions Our study points to the role of three key historical events in Narcissus diversification: tectonic shifts of the Alboran domain in the western Mediterranean, the Messinian salinity crisis, and the onset of the Mediterranean climate followed by periods of repeated glaciation. Diversification of section Apodanthi probably resulted from allopatric speciation, while subgenus Hermione may have shown more sympatric speciation and high dispersal, despite the lack of apparent adaptations to long‐distance dispersal. This is best exemplified by the presence of both ancestral and recent haplotypes of N. tazetta across the Mediterranean. 相似文献
44.
This study uses individual-level longitudinal data from Iceland, a country that experienced a severe economic crisis in 2008 and substantial recovery by 2012, to investigate the extent to which the effects of a recession on health behaviors are lingering or short-lived and to explore trajectories in health behaviors from pre-crisis boom, to crisis, to recovery. Health-compromising behaviors (smoking, heavy drinking, sugared soft drinks, sweets, fast food, and tanning) declined during the crisis, and all but sweets continued to decline during the recovery. Health-promoting behaviors (consumption of fruit, fish oil, and vitamins/minerals and getting recommended sleep) followed more idiosyncratic paths. Overall, most behaviors reverted back to their pre-crisis levels or trends during the recovery, and these short-term deviations in trajectories were probably too short-lived in this recession to have major impacts on health or mortality. A notable exception is for binge drinking, which declined by 10% during the 2 crisis years, continued to fall (at a slower rate of 8%) during the 3 recovery years, and did not revert back to the upward pre-crisis trend during our observation period. These lingering effects, which directionally run counter to the pre-crisis upward trend in consumption and do not reflect price increases during the recovery period, suggest that alcohol is a potential pathway by which recessions improve health and/or reduce mortality. 相似文献
45.
Lynton K. Caldwell 《Human ecology: an interdisciplinary journal》1976,4(1):31-45
The energy crisis is an aspect of the larger approaching crisis of expanding industrial society in a world in which certain critical parameters are finite. This megacrisis involves the role of growth in population, production, consumption, and waste. The insitutions of modern industrial society have been better adapted to promote this growth than to control or direct it. Even in societies where mechanisms of state planning should, in theory, enable government to deal rationally with the growth problem, ideological commitments to general growth have, in effect, prevented the problem from being addressed. In the United States, the pervasive commitment to growth has been built into institutional arrangements to a degree that handicaps efforts to consider the energy problem in its full context. Energy policy therefore tends to be reactive to events rather than the result of a comprehensive long-range assessment of needs and priorities.
Presented at the 140th Meeting of the American Association for the Advancement of Science, Session on Energy and Society, San Francisco Hilton Hotel, February 24 to March 2, 1974. Revised and extended for publication inHuman Ecology.
Arthur F. Bentley Professor of Political Science and Professor of Public and Environmental Affairs, Indiana University, Bloomington, Indiana. 相似文献
46.
This paper presents evidence on how the consumption of legal and illegal drugs has changed in response to the Great Recession in Spain. We use a large scale survey from 2005 to 2011 to analyze the association between changes in local economic conditions and drug consumption among individuals aged 15–64. Although Spain was one of the countries hardest hit by the economic downturn, the crisis was unevenly felt across the country. Therefore, we exploit this difference in unemployment rates across provinces to identify the effects of business cycle variations on the consumption of legal and illegal drugs. To the best of our knowledge, this is the first study to find a relation between the deterioration of local economic conditions and a strong increase in the consumption of marihuana and cocaine. We also report a decrease in alcohol consumption but a significant escalation in abusive smoking behavior (smoking every day). We believe that these findings are important not only for the potential negative implications at the individual level but also for the costs to society as a whole. 相似文献
47.
Field studies of wild nonhuman primates have grown exponentially over the past 40 years and our knowledge of primate behavior, ecology, and social, and mating systems has expanded greatly. However, we are facing a major extinction crisis with some 60% of all primate species listed as threatened and more than 75% of species with declining populations. The primary factor driving primate population decline is human population increase, which over the past 50 years has resulted in the unsustainable conversion and degradation of natural landscapes for industrial agriculture, the production of nonagricultural commodities for international trade, pastureland for cattle, dam construction, fossil fuel exploration, mining, and the construction of road networks and infrastructure to support large urban centers. Recent ecological modeling predicts that by the end of the century, the four primate‐richest countries in the world will lose 32–78% of their existing primate habitat to agricultural expansion, and nine of the top 15 primate‐richest countries are expected to have 80–100% of their primate species extinct or threatened with extinction. If we are going to save the world's primates, the time to act is now! Not only should all primate field research include a strong conservation component, but in addition we must actively join with our professional societies, zoos and research facilities, universities, conservation organizations, concerned business leaders, global citizens, like‐minded political leaders, and grassroots organizations to inform, demand and direct governments, multinational corporations, and international organizations to engage in transformational change to protect biodiversity and seek environmental justice against those entities that actively destroy our planet. As the chief academic discipline dedicated to the study of primates, we must organize and collectively move from being advocates for primate conservation to becoming activists for primate conservation. This is a call to action. 相似文献
48.
目的:探讨颌面部皮肤软组织大面积缺损凹陷的理想修复方法。方法:本组6例均为爆炸伤后颌面部皮肤软组织缺损及严重凹陷畸形,采用胸三角皮肤扩张形成带蒂皮瓣修复上述皮肤缺损及自体脂肪移植纠正残存凹陷畸形。手术分五步进行:1.胸三角深筋膜浅层埋植500mL-800mL皮肤扩张器并注水扩张3个月。2井艮据面颈部预计皮肤缺损大小及形状作皮瓣预制并面部局部皮瓣纠正器官移位。3.带蒂皮瓣转移修复颌面部缺损。4.蒂部延迟及断蒂微整形。5.自体脂肪移植。结果:所有皮瓣成活良好,皮瓣色质接近面颈部周围正常皮肤,缺损畸形修复,外观形态好,供区直接缝合无需植皮,取得了较好的面部改观效果。结论:对于面部大面积皮肤软组织缺损,合并面部凹陷、面部器官缺损及移位,采取胸三角扩张延迟预制皮瓣并自体脂肪移植修复可取得良好的整复效果,为颌面部战创伤畸形提供了理想的修复方法。 相似文献
49.
50.
核酸侵入反应是由5’核酸内切酶或flap内切酶催化的,能够识别切割核酸片段形成的特异性结构的一类反应。近年来发展了很多基于该反应的生物大分子检测技术,能够对DNA、RNA、miRNA及蛋白质进行高灵敏、高特异性的测定。这些技术大都无需扩增待测靶标,极大地降低了扩增产物交叉污染的风险,在临床检测中具有很大的应用前景。本文对这些检测技术的原理及应用作简要综述。 相似文献