Evolution of the late Quaternary San Gregorio Magno tectono‐karstic basin (southern Italy) inferred from geomorphological,tephrostratigraphical and palaeoecological analyses: tectonic implications     

G. Aiello  A. Ascione  D. Barra  R. Munno  P. Petrosino  E. Russo Ermolli  F. Villani 《第四纪科学杂志》2007,22(3):233-245

The Pantano di San Gregorio Magno is a 4.7 km² large tectono‐karstic basin located in the axial belt of the Southern Apennines, an area affected by intense seismicity. The basin was formed in the Middle Pleistocene and is presently undissected. It is filled by lacustrine sediments (clays, silts and pyroclastic sands) passing laterally into alluvial fan deposits. Geomorphological investigations were integrated with tephrostratigraphical, palynological and palaeoecological analyses of a 61 m thick core (not reaching the bedrock). The multiproxy analysis of the S. Gregorio Magno record shows that, over the last 200k yr, the basin hosted a freshwater lake with an oscillating level. Age constraints provided by the tephrostratigraphic record allowed estimation of the sedimentation rate, which varied strongly through time. Evolution of the basin resulted from the complex combination of tectonic subsidence, karst processes and changing amounts of sedimentary inputs. The latter was influenced by allogenic contributions related both to primary and reworked volcanoclastic inputs and was climate‐driven. The overall evidence, which indicates that in the long‐term the accumulation rate substantially counterbalanced the accommodation space created by faulting, suggests that the basin evolution was also modulated by changing subsidence rates. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

桑托斯盆地L构造Aptian期火山喷发旋回特征与Itapema组介壳灰岩沉积     

赵健  赵俊峰  任康绪  王红平  王朝锋  阳孝法  杨柳 《地质学报》2023,97(2):539-552

桑托斯盆地裂陷初期岩浆活动与储层发育关系密切。本文以盆地L区块火成岩-介壳灰岩复合体为研究对象,通过对火成岩岩石学、年代学测试及钻井、测井资料分析等,首次明确了桑托斯盆地裂陷初期岩浆活动特征及其对介壳灰岩沉积过程的控制,并指出介壳灰岩储层的分布特征。L区块内火成岩分属晚白垩世Santonian期—Campanian期和早白垩世Aptian两期岩浆活动产物,并以Aptian期为主,至少经历了7次不连续喷发和3次侵入过程,形成了块状玄武岩、杏仁状玄武岩和玻基斑状玄武岩(含再沉积玻基斑状玄武岩)等喷发相火成岩和以辉绿岩(局部属粗玄岩)、煌斑岩形式产出的侵入相火成岩。Aptian期岩浆多期活动重塑了古地貌,形成了局部构造凸起,促成并控制了下白垩统Itapema组至少6期介壳灰岩沉积,最终形成了～620 m厚火成岩-介壳灰岩复合体。介壳灰岩储层呈透镜体形状,以“散点式”不连续分布在Aptian期盆内古隆、古断阶(坡)等区域,横向连续性差,垂向连通性受限,其发育规模和质量受古地貌及水深条件等影响。  相似文献   

后装配组件的分析与设计方法     

蒋建民  舒红平 《成都信息工程学院学报》2003,18(1):16-19

后装配组件的分析与设计方法是为如何方便组装、拆卸和替换组件而提出的，它是建立在面向对象和基于组件的软件工程基础上，把组件的概念引入到需求分析中，建立起组件与具体需求的映射关系。该方法能根据用户需求变化直接确定要维护的组件，从而提高组件的适应能力。  相似文献   

Infrared spectral evolution of carbon stars     

Pei-Sheng Chen  Xiao-Hong Yang  Hong-Guang Shan National Astronomical Observatories /Yunnan Observatory  Key Laboratory for the Structure  Evolution of Celestial Objects  Chinese Academy of Sciences  Kunming  China 《中国天文和天体物理学报》2010,10(4)

We collected almost all Highly Processed Data Products(HPDP)of ISO SWS01 spectra for the Galactic visual carbon stars,infrared carbon stars,extreme carbon stars and carbon-rich proto-planetary nebulae(PPNs).Those infrared spectra are primarily analyzed and discussed.It is shown that either spectral shapes/peaks,or main molecular/dust features are evidenced to change in the sequence of visual carbon stars,infrared carbon stars,extreme carbon stars and carbon-rich PPNs.Statistically,in this sequence,continua are gradually changed from blue to red and locations of spectral peaks of continua are also gradually changed from short wavelengths to long wavelengths.In addition,in this sequence,intensifies of main molecular/dust features are also gradually changed from prominent in the short wavelengths to prominent in the long wavelengths.Furthermore,from 2MASS and IRAS photometric data,the sequence is also proved.Results in this paper strongly support the previous suggestion for the evolution sequence of carbon-rich objects in our Galaxy,that is the sequence of visual carbon stars→infrared carbon stars→extreme carbon stars→carbon-rich PPNs.  相似文献   

Distribution and Forming Model of Fluvial Terrace in the Huangshui Catchment and its Tectonic Indication     

WANG Xianyan  LU Huayu  Jef Vandenberghe  CHEN Zhongyan  LI Langpin 《《地质学报》英文版》2010,84(2):415-423

<正>The Huang Shui River,a main tributary of the Yellow River,crosses a series of tectonically subsided and uplifted areas that show different patterns of terrace formation.The distribution of fluvial terrace of the Huang Shui River is studied through topographic and sedimentologic terrace mapping.Three terraces in the Haiyan Basin,four terraces in the Huangyuan Basin,19 terraces in the Xi'ning Basin(the four high terraces may belong to another river),nine terraces in the Ping'an Basin, five terraces in the Ledu Basin and 12 terraces in the Minhe Basin are recognized.Sedimentology research shows that the geomorphologic and sedimentological pattern of the Huang Shui River,which is located at the margin of Tibet,are different from that of the rivers at other regions.The formation process of the terrace is more complicated at the Huang Shui catchment:both accumulation terrace and erosion terrace were formed in each basin and accumulation terraces were developed in some basins when erosion terraces were formed in other basins,indicating fluvial aggradation may occur in some basins simultaneously with river incision in other basins.A conceptual model of the formation process of these two kinds of fluvial terraces at Huang Shui catchment is brought forward in this paper.First,the equilibrium state of the river is broken because of climatic change and/or tectonic movement,and the river incises in all basins in the whole catchment until reaching a new equilibrium state.Then,the downstream basin subsides quickly and the equilibrium state is broken again,and the river incises at upstream basins while the river accumulates at the subsidence basin quickly until approaching a new equilibrium state again.Finally,the river incises in the whole catchment because of climatic change and/or tectonic movement and the accumulation terrace is formed at the subsidence basin while the erosion terrace is formed at other basins.The existence of the accumulation terrace implied the tectonic subsidence in the sub-basins in Huang Shui catchment.These tectonic subsidence movements gradually developed from the downstream Minhe Basin to the upstream Huangyuan Basin.Dating the terrace sequence has potential to uncover the relationship between the subsidence in the catchment and the regional tectonic at the northeastern Tibetan Plateau.  相似文献   

西北地区晚第四纪沉积地层一元正脂肪酸酰胺分布特征及古气候意义     

蒲阳  张虎才  雷国良  常凤琴  杨明生  庞有智 《地球科学进展》2010,25(5):533-542

利用气相色谱质谱联用仪在中国西北地区晚第四纪沉积地层中检测出一类特殊的类脂物分子--一元正脂肪酸酰胺.根据其碳数分布特征及前人的研究成果,认为一元正脂肪酸酰胺来源于各种生物体,产生于生物的某些生理活动过程,而不是来源于石油残余物及各种可能的污染.通过对比3个不同区域相近时期古湖相及黄土沉积地层中的脂肪酸酰胺分布特征,认为柴达木盆地可能不是黄土沉积的主要物源区,而额济纳盆地及邻近区域对黄土堆积有着重要的贡献或具有相同的物源.典型黄土沉积地层中UFAA值(不饱和与饱和脂肪酸酰胺相对含量的比值)与粒度、磁化率等指标具有很好的可对比性,特别是在相对暖湿阶段UFAA值呈现了明显的低值.这一现象表明脂肪酸酰胺在沉积地层中的变化受控于气候变化所导致的成岩作用强度的变化,从而记录了气候变化信息.通过研究,认为生物生理活动过程中所产生的一元正脂肪酸酰胺与构成细胞膜的类脂物分子一样,可记录古气候变化.  相似文献   

青海南部杂多地区新建扎青组的地层层序及地质意义     

王毅智  叶占福  李琳业  宋泰忠  任二峰  祁生胜  王伟  裴生菊  许长青 《西北地质》2010,43(3):20-27

在青藏高原北羌塘盆地青海南部,青海省杂多县扎青乡地区的然者涌一带,发现以基性火山熔岩为主夹有中基性火山碎屑岩,具大陆板内裂谷拉斑玄武岩喷发特点的一套火山地层。该地层底部角度不整合接触覆盖在早中二叠世开心岭群诺日巴尕日保组、九十道班组之上,其上被晚三叠世结扎群甲丕拉组角度不整合覆盖。主要岩性为灰绿—灰紫色橄榄玄武岩、粗面玄武岩、玄武粗安岩及流纹岩、中基性火山角砾岩、角砾凝灰岩夹少量流纹岩和紫红色岩屑砂岩及细砾岩,其特征与峨眉山低钛玄武岩相似,具陆相喷发-沉积特征。区域对比在北羌塘地区具有独特地层特征,可与四川峨眉山玄武岩地层进行对比。而区域上该地区晚二叠世主要为一套海陆交互相含煤碎屑岩建造,未发现陆相火山岩出露,本文建立正式地层单位扎青组,以供参考,其时代暂归晚二叠—早三叠世。  相似文献   

松辽盆地反转期的界定   总被引：1，自引：0，他引：1  

陈骁  李忠权  陈均亮  李洪奎  张彤 《地质通报》2010,29(2)

松辽盆地的构造反转对油气生成、运移和聚集保存有明显的控制作用.以往的研究认为,松辽盆地晚期经历了嫩江组沉积末期、明水组沉积末期和古近纪的多期反转.通过对松辽盆地北部进行剖面与平面的构造演化分析,认为嫩江组沉积末期为南北向差异升降活动,未引起地层褶皱变形和构造格局的改变,该期形成了区域伸展不整合面;明水组沉积末期松辽盆地从区域拉张转为挤压,盆地表现为东西向缩短,构造格局发生了性质上的变化,形成了一系列反转构造,该期构造反转奠定了盆地现今的构造格局.构造物理模拟实验进一步证明,松辽盆地不同方向的反转构造带为明水组沉积末期形成的.  相似文献   

九江市蓼花剖面末次冰期中晚期沉积的粒度端元特征与气候变化     

李世乾  李志文  周万蓬  杜丁丁  黎武标 《热带地理》2023,43(1):135-143

鄱阳湖湖滨地区广泛分布着晚第四纪风沙沉积序列。在星子县沙岭沙山进行野外调查后选择蓼花剖面开展工作,测试了地质时代和粒度,对粒度结果使用端元分析模型进行研究,探讨该区域末次冰期中晚期的气候变化规律。结果显示：该剖面由湖相-古土壤-沙丘砂等沉积相叠覆堆积组成,形成于末次冰期中晚期（48.8—17.1 ka）。端元分析模型将粒度数据分解出3个不同的粒度端元,不同端元组分在垂向上呈峰谷交替的旋回变化,EM1代表粉砂端元组分,峰值对应湖相和古土壤发育时期;EM2和EM3代表中砂—粗砂端元组分,峰值对应沙丘砂发育期,这些峰谷交替变化的规律指示了末次冰期的季风演变以及气候波动变化,万年尺度上表现为LH10 (48.8—39.9 ka)和LH3～LH5 (28.1—17.1 ka)的冬季风强盛期,分别对应深海氧同位素的MIS3b和MIS2阶段。LH6～LH9 (39.9—28.1 ka)为温暖的夏季风时期,对应深海氧同位素的MIS3a阶段。这些变化与YZ洞石笋氧同位素以及格陵兰冰心有良好的对应,与全球气候变化基本一致。  相似文献   

“南音不幸而盛”:冯梦龙批评晚明剧坛析辨     

王小岩 《广东海洋大学学报》2014,(5):58-62

冯梦龙主张戏曲创作要"奇",且"调协韵严",基于此,他对晚明剧坛创作中存在的问题予以批评。这些批评从两个方面展开。在"曲"的方面,他批评了民间传奇创作、文人创新、汤显祖及其追随者等;在"戏"的方面,他提出"奇"的标准——"事奇"和"掀翻窠臼",并批评很多作品难以做到这两点。冯梦龙对晚明剧坛的批评原则立于对形式的推崇,故而有其局限性。  相似文献