新疆库鲁克塔格地区寒武-奥陶系硅质岩的岩石学特征及其成因分析   总被引：2，自引：0，他引：2  

刘万洙  白雪峰  包亚范  王璞珺 《新疆地质》2006,24(4):344-347,I0007

新疆塔里木盆地东北缘库鲁克塔格地区硅质岩主要出现在下寒武统和下、中奥陶统海相沉积层序.从下寒武统到中奥陶统硅质岩岩性自下而上由黑色致密块状非晶质硅质岩到灰黑色非晶质含泥质(碳质)放射虫硅质岩再到含外碎屑放射虫硅质岩;岩石中放射虫化石的含量逐渐增多,个体逐渐变大;放射虫化石外表呈现的搬运磨蚀特征显示具逐渐增强的趋势;岩石的成层性变好,粒度也表现出明显的正韵律性.据硅质岩的岩性、生物、层序和构造背景分析认为:硅质岩沉积所需的SiO2有海底火山气射和生物作用两个来源;自下而上生物作用提供的硅质逐渐占主导,形成水深逐渐变浅,从寒武纪深海硅质岩变为中奥陶统次深海硅质岩.  相似文献   

用数值模拟方法研究第四纪古气候──以LLN二维模式为例   总被引：1，自引：0，他引：1       下载免费PDF全文

李雪松 《第四纪研究》1996,16(4):289-299

本文着重介绍LLN模式对中晚第四纪大陆冰量变迁的模拟研究。由于天文学研究已经推算出大气层顶部太阳辐射过去和将来的长期变化，因而对本文的LLN二维模式而言，能否有效地进行古气候模拟在很大程度上取决于对古CO₂浓度的重建。随着对第四纪CO₂历史研究的不断深入，LLN模式对古气候长期变迁的模拟已从最初的末次冰期－间冰期延伸到0.6Ma B.P..。模拟的大陆冰量变化与地质记录对比良好，二者在与地球轨道要素有关的天文频率上的波动具有很高的相关性。  相似文献   

对鱼台盆地的新认识   总被引：1，自引：0，他引：1  

李钟模 《盐湖研究》1996,4(1):13-21

根据微体生物资料，将原定之始新统“官庄组”修正为始新统至上古新统三垛组、戴南组和阜宁组四段），将原定７８—４孔和丰钾３孔宫庄组更为下白垩统青山组；综合地震、重力、古生物资料对鱼台盆地有了新的认识：其一，鸳楼断层西段不存在而是向北东方向延伸；其二，认为鱼台盆地是一个统一的盆地，所谓师砦、欢口、鱼台三个被此分割的盆地，实际上是三个相互连通的次凹；其三，提出了李阁附近是盆地的沉降中心和成钾有利部位；其四，提出了有海源的新观点。  相似文献   

Impact of amoco cadiz oil spill on the muddy fine sand Abra alba and Melinna palmata community from the Bay of Morlaix     

Jean-Claude Dauvin 《Estuarine, Coastal and Shelf Science》1982,14(5):517-531

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有益生物利用技术研发的限制因素与对策     

侯怀恩  赵风兰  孟庆法  文春波 《地域研究与开发》2007,26(2):117-119,128

农田生态系统的生物多样性受到限制,害虫失去了天敌的控制易形成爆发性危害;杀虫剂的使用在消灭害虫的同时也消灭了害虫的天敌,遗传变异和有毒环境的自然选择使害虫产生高抗性,导致杀虫剂的防治效果下降,于是不得不增加农药的使用量而陷入恶性循环.适当增加环境中有益生物的数量可实现害虫的有效控制;有益生物人工饲养技术的发展为防治农业害虫奠定了较好的基础.但是,投资与收益者不能统一的矛盾以及滥用农药使生物防治技术的应用受到限制.加大政府的支持力度,建立有益生物利用保护区和适宜的投入运行机制,加强多种生物配合利用方面的研究可促进有益生物利用技术的研发与推广.  相似文献   

Offshore oil platforms and fouling communities in the southern Arabian Gulf (Abu Dhabi)   总被引：1，自引：0，他引：1  

Stachowitsch M  Kikinger R  Herler J  Zolda P  Geutebrück E 《Marine pollution bulletin》2002,44(9):853-860

This study examined the fouling organisms on the legs of offshore oil platforms at two sites in the southern Arabian Gulf (offshore Abu Dhabi, United Arab Emirates). 100% of the metal structures was colonized by encrusting organisms. Both the number of individuals and the total biomass tended to decrease with depth. The total weight of dead shells always exceeded that of living organisms. Sessile filter feeders dominated the biomass, whereas small mobile forms had the largest number of individuals. The biomass at the deeper platform (22 m) was dominated by bivalves, barnacles and bryozoans, while polychaetes and amphipods had the greatest number of individuals. Biomass values here ranged from 1 g/0.1 m2 at 20 m to 147 g/0.1 m2 at 5 m; the corresponding individual numbers were 266 (20 m) and 11,814 indiv./0.1 m2 (5 m). The results at the shallower platform (11 m) differed in several respects: barnacles clearly dominated over bivalves, and sponges exceeded byrozoans, while total individual numbers fell due to a decline in polychaete dominance. Biomass values here ranged from 84 g/0.1 m2 at 10 m to 153 g/0.1 m2 at 0 m; the corresponding individual numbers were 695 (10 m) and 3,125 indiv./0.1 m2 (0 m). The potential role of such fouling communities on artificial structures in the Gulf is discussed.  相似文献   

河北黄骅近岸石油污染对海洋生物体内石油烃含量的影响     

崔毅  陈碧鹃  宋云利  吴彰宽 《海洋科学进展》2000,18(3):66-71

对河北黄骅沿海1995年2次调查所捕获的鱼、虾、贝类等18种样品的测定结果表明,受测海洋生物均检出石油烃,双壳类生物体内石油烃含量高于甲壳类和鱼类.该海域海洋生物体内石油烃含量水平远低于国内外污染严重的水域.从分析结果看,该海域目前石油污染特点主要以慢性油污染为主.  相似文献   

悬浮液中硫酸根对改性粘土去除藻华生物效率的影响     

刘扬  俞志明  曹西华  宋秀贤  张雅琪  林勇新 《海洋与湖沼》2014,45(4):734-740

本文研究了改性粘土悬浮液中硫酸根对其去除藻华生物效率的影响,通过Zeta电位、沉降速率和粒径分布等分析了改性粘土对藻华生物的去除效率,探讨了硫酸根与改性粘土的作用机制。结果显示:改性粘土对抑食金球藻(Aureococcus anophagefferens)的去除效率随悬浮液中硫酸根浓度的增加呈现先降低后升高的趋势,改性湖北土和改性江苏土对抑食金球藻去除率较低时(40%)的硫酸根浓度分别为6.46×10–3—2.42×10–1mol/L和6.46×10–3—2.42×10–2mol/L;改性粘土颗粒的Zeta电位随着硫酸根浓度的增加而降低,然后保持相对稳定;悬浮液中改性粘土颗粒的沉降速率和中值粒径D50呈现先增加后降低的趋势,对于改性江苏土,在硫酸根浓度为2.42×10–2mol/L时颗粒的沉降速率最大。综上所述,悬浮液中硫酸根主要通过降低粘土颗粒表面电荷密度、桥联改性粘土组分和影响粘土颗粒分散性等作用影响改性粘土对藻华生物的去除效率。  相似文献   

Validation of Arenicola marina in field toxicity bioassays using benthic cages: biomarkers as tools for assessing sediment quality     

Ramos-Gómez J  Martins M  Raimundo J  Vale C  Martín-Díaz ML  DelValls TA 《Marine pollution bulletin》2011,62(7):1538-1549

Sediment toxicity assessments using caged organisms present advantages over using laboratory and native community studies. The use of caged Arenicola marina in sediment toxicity assessments was evaluated. Lugworms were exposed in situ to sediments from coastal and port areas in Spain for seven days, and the activities of the biotransformation enzymes ethoxyresorufin O-deethylase, dibenzylfluorescein dealkylase and glutathione S-transferase, the activities of the antioxidant enzymes glutathione reductase and glutathione peroxidase and lipid peroxidation were then analyzed as biomarkers. Biomarker results and sediment physicochemical data were integrated. Cádiz Bay (SW Spain) sediments presented metal contamination that was not linked to a biochemical response. In LPGC Port (SW Spain), Pb contamination exhibited a moderate toxic potential, while PAHs, and presumably pharmaceuticals, provoked biochemical responses that efficiently prevented lipid peroxidation. In Santander Bay (N Spain), exposure to PAHs and, presumably, pharmaceuticals induced biomarker responses, but lipid peroxidation occurred nevertheless. These results indicated that caged A. marina were effective for the assessment of sediment quality and that the selected biomarkers were sufficiently sensitive to identify chemical exposure and toxicity.  相似文献   

广东碣石湾污损生物生态研究   总被引：1，自引：0，他引：1  

林传旭  邹晓理  王华接  严岩 《海洋通报》2011,30(3):287-293

2008年5月至2009年4月,对广东碣石湾海域进行周年污损生物挂板试验,本次调查共记录该海域污损生物86种,多属于亚热带沿岸的广布种,其中优势种为网纹纹藤壶(Amphibalanus reticulatus)、翡翠股贻贝(Perna viridis)、太平洋侧花海葵(Anthopleurapacifica)、水云(E...  相似文献