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161.
Arch M. Reid W.I. Ridley Russell S. Harmon Pete Jakes̆ 《Geochimica et cosmochimica acta》1973,37(3):695-699
Glasses in a soil sample (14156) from the middle layer of the trench at the Fra Mauro landing site show a wide range of compositions clustered around certain preferred compositions. Ninety per cent of the glasses are of two major types—Fra Mauro basalt (63 per cent) with high K and 17 weight per cent Al2O3 and Highland basalt or anorthositic gabbro (27 per cent) with low K and 25–26 weight per cent Al2O3. The glass population is almost identical with that of the comprehensive soil 14259 (Apollo Soil Survey, 1971). 相似文献
162.
We investigated the implementation and sustainability of village conservation agreements and village conservation grants facilitated by an integrated conservation and development project (ICDP) around the Kerinci Seblat National Park, Sumatra, Indonesia, 5 years after the project closed. Forty-three percent of agreement actions (n = 180) and 30% of grant activities (n = 74) were sustained. Informants identified numerous factors influencing success, but statistical tests failed to detect simple explanations. Conservation-livelihood agreements have a greater chance of success when preexisting factors are understood and the purpose of the agreement itself is clearly defined. 相似文献
163.
PAH transport by sinking particles in the open Mediterranean Sea: a 1 year sediment trap study 总被引:1,自引:0,他引:1
Bouloubassi I Méjanelle L Pete R Fillaux J Lorre A Point V 《Marine pollution bulletin》2006,52(5):560-571
One year time series of sinking particles were collected at two depths in the open Mediterranean Sea and analysed for polycyclic aromatic hydrocarbons (PAH). Average total PAH concentrations were 593+/-284 ng g(-1) at 250 m and 551 +/- 198 ng g(-1) at 2850 m. Total PAH fluxes averaged 73 +/- 58 ng m(-2) d(-1) at 250 m and 53 +/- 39 ng m(-2) d(-1) at 2850 m. Contamination levels and, thus, exposure of marine organisms to PAH are comparable in surface and deep waters. Deep waters appear as a significant, yet overlooked, PAH sink. PAH temporal patterns show noticeable seasonality. This is partly due to varying levels of specific components such as the winter increase of pyrolytic PAH. Downward transport processes and the nature of sinking particles also impact on PAH fluxes, as inferred during periods of increasing productivity. Different phase-associations and interactions with particulate organic carbon for low-MW fossil PAH and high-MW pyrolytic PAH influence their downward transport efficiency. 相似文献
164.
Internal architecture of a till sheet,Tiskilwa Formation,north‐central Illinois,USA: Application of architectural element analysis 下载免费PDF全文
Jessica M. Slomka Carolyn H. Eyles Riley P. M. Mulligan Edward Donald Mckay III Richard C. Berg 《Sedimentology》2015,62(5):1328-1359
Thick till sheets deposited during the Quaternary form significant aquitards in many areas of North America. However, the detailed sedimentary heterogeneity and architecture and depositional history of till units are not well understood. This study utilizes architectural element analysis to delineate the internal sedimentary architecture of the Tiskilwa Formation exposed at two outcrop sections in north‐central Illinois, USA. Architectural element analysis facilitates systematic delineation of sedimentary architecture based on the nature of facies contacts and change in facies associations, delineation of unit geometries and understanding of depositional processes at different scales of resolution; making architectural element analysis suitable for the sedimentological analysis and palaeoenvironmental reconstruction of subglacial deposits. Eleven facies types are identified in this study, including sand, gravel and diamict facies that record a suite of subglacial depositional processes. Detailed analysis of facies contacts (bounding surface hierarchy) and change in facies associations allows the delineation of five architectural elements, including coarse‐grained lens, coarse‐grained sheet, mixed zone, diamict lens and diamict sheet elements. The spatial arrangement and genetic interpretation of elements, and their spatial relationship with fifth‐order bounding surfaces, allows the delineation of five larger scale architectural units (‘element associations’), which can be mapped in the local study area and record at least three stacked successions of meltwater accumulation and till deposition. The results of this study can be utilized for architectural analysis of till sheets and provide insight to groundwater flow pathways through till in the study area and elsewhere. 相似文献
165.
Zhangcai QIN Xi DENG Bronson GRISCOM Yao HUANG Tingting LI Pete SMITH Wenping YUAN Wen ZHANG 《大气科学进展》2021,38(6):889-895
正"I call on all leaders worldwide to declare a State of Climate Emergency in their own countries until carbon neutrality is reached."–António GUTERRES(United Nations Secretary General), 12 December, 2020 There is no shortcut to a carbon neutral society; solutions are urgently required from both energy industrial sectors and global ecosystems. 相似文献