川东北地区台地边缘礁、滩气藏沉积与储层特征

普光、元坝和龙岗等多个大、中型天然气田的发现,揭示了川东北地区长兴组-飞仙关组环开江-梁平陆棚东西两侧和城口-鄂西陆棚西侧台缘礁、滩带具有巨大油气勘探潜力。勘探实践证实不同部位台缘带的气藏特点及相关礁、滩沉积和储层特征均具有明显差异性。文中在层序地层学、沉积学和储层评价等研究基础上对这些差异性开展了分析工作。川东北地区长兴组-飞仙关组识别出两个三级层序,它们均由海侵和高位体系域构成,总体表现为水体向上变浅序列。研究区内不同部位的台缘带沉积和储层具有明显的差异,长兴期环开江-梁平陆棚东西两侧台缘地貌相近,铁厂河-普光-高峰场台缘带具加积为主、台缘斜坡陡、滩薄、生物礁发育的特点,上部白云岩化强;元坝-龙岗台缘带具前积和侧积明显、斜坡略缓、礁和滩均发育的特点,礁滩上部白云岩化强,孔隙型储层发育且物性较好;飞仙关期台缘不对称性明显,铁厂河-普光-高峰场台缘带仍以加积型为主,飞二段鲕滩发育,白云岩化强,孔隙型储层发育,具有储层厚度大和物性好的特点;元坝-龙岗台缘带飞二段发育鲕滩,但滩厚度薄、白云岩化弱,以孔隙型储层为主,储层物性略差。宣汉盘龙洞-见天坝长兴组台缘生物礁滩相及飞二段台缘鲕滩发育,白云岩化强,易于形成较好的储层。通过综合分析研究认为不同部位台缘带沉积及储层分布明显受同沉积古地貌、白云岩化强度、断裂、埋藏期成岩作用和流体活动等综合因素控制。     

一种快速准确校正手持式GPS的方法

目前,手持式GPS已成为地质工作人员必不可少的工具之一,正确使用和校正GPS是每个技术人员必须掌握的。在工作实践中,笔者总结出GPS的显示坐标X,Y变化量与校正参数DX,DY,DZ的变化量的比值(即变化率)在某一地区是一定值(即线性关系),不同地区该定值不同。通过变化量的此种线性关系用解方程法可快速准确地确定DX,DY,DZ参数,且只要满足该方程解的不同组合的DX,DY,DZ均可作为该地区正确的校正参数,从而可准确校正GPS。     

陆生植被对河流沉积作用的影响：生物沉积作用研究的一个重要主题*

河流是大陆景观最为动态化的地貌构成单元,地质学家经过长期的研究,得出了一个引人注目的假说,即古生代中期曲流河的显著发育与陆生植被的繁盛存在紧密的联系,从而导致了在陆生植被对河流沉积作用影响方面的深入研究。尽管还存在一些不同的认识和争论,陆生植被对河流沉积作用的影响,得到了越来越多的地质事实的支持。立足于前人的研究成果,从陆生植被阶段的划分以及植物在古生代早中期关键的演变事件入手,介绍植被的起源和演化与河流沉积作用尤其是河流样式演变之间的耦合关系。厘清上述科学理念的变化和进步,将有助于河流相沉积的正确解释,从而为现代和古代河流过程的进一步研究提供重要的思考线索和研究途径。更为重要的是,在地球历史长河之中,有胚植物（陆生植物）在陆生大陆景观上的古生代繁殖是最为壮观的变化之一,由此而造成的全球变化包括：（1）由于岩石风化作用和碳储存的增强,将造成的大气圈二氧化碳含量的降低;（2）晚古生代冰川作用;（3）陆生营养物径流量的增加与海洋生物的灭绝事件之间的联系等。所以,陆生植被的起源与演化对河流沉积作用的影响,就成为生物沉积作用研究的一个重要主题。     

长江口崇明东滩不同植被带沉积速率研究

利用2007年丰水期、枯水期在崇明东滩芦苇带、藨草带和光滩采集的6根沉积物柱状样,研究了沉积物的粒度特征和过剩的210Pb和228Th及7Be活度的垂向分布特征,探讨了由陆地向海洋不同植被间的沉积物粒度变化规律。依据恒定比活度沉积速率模型,估算了不同时间尺度的崇明东滩芦苇带、藨草带和光滩的表观沉积速率。结果表明:3种核素示踪的崇明东滩的表观沉积速率都随潮滩植被的不同从陆到海方向逐渐降低,同时依过剩的210Pb和228Th,7Be的次序而增大。由过剩的210Pb和228Th计算的夏季沉积速率比冬季的稍高,而由7Be计算的夏季表观沉积速率则明显高于冬季的。结合沉积物粒度的时空分布和这些核素的大气通量,对利用这些核素测定潮滩沉积速率的影响因素进行了探讨。     

Local variability in temperature, humidity and radiation in the BaekduDaegan Mountain protected area of Korea

A novel embedded sensor network records changes in key climatic-environmental variables over a range of altitude in the BaekduDaegan Mountain (BDM) of Gangwon Province in Korea, a protected mountain region with unique biodiversity undergoing climate change research. The investigated area is subdivided into three horizontal north-south study areas. Three variables, temperature (T, ℃), relative humidity (RH, %), and light intensity (LI, lumens m -2 , or lux, lx), have been continuously measured at hourly intervals from June, 2010 to September, 2011 using HOBO H8 devices at 10 fixed study sites. These hourly observations are aggregated to monthly, seasonal and annual mean values, and results are summarized to inaugurate a long-term climate change investigation. A region wide T difference in accordance with altitude, or lapse rate, over the interval is calculated as 0.4℃100 m -1 . T lapse rates change seasonally, with winter lapse rates being greater than those of summer. RH is elevated in summer compared to other seasons. LI within forestland is lower during summer and higher during other seasons. The obtained results could closely relate to the vegetation type and structure and the terrain state since data loggers were located in forestland.     

从影响因子看《大地测量与地球动力学》的质量现状

通过分析影响因子与期刊质量的关系,结合《大地测量与地球动力学》2002-2010年影响因子的变化,客观地评价该刊的质量现状.     

Prolonged impact of earthquake-induced landslides on sediment yield in a mountain watershed: The Tanzawa region, Japan

To determine for how long a landslide affects sediment discharge, the sediment yields of 15 check-dam basins were compared with the time series of landslide distributions in a mountain basin in the Tanzawa region, central Japan. The distribution of sediment yield was quantitatively estimated from deposition in the sediment pools of check dams. The relationship between the landslide history and sediment discharge in the Nakagawa River basin was examined for an approximately 80-year period. Two major landslide events occurred during this period: the 1923 Kanto Earthquake and the 1972 disaster caused by heavy rainfall. The resulting trend in sediment discharge of the whole basin, estimated using reservoir sedimentation in the Miho Dam at its base, was nearly constant, with high sediment discharge (2897 m³ km^− 2 yr^− 1) in the intervening quarter-century, despite the recovery of vegetation on landslide areas in this period. Comparisons of the landslide distributions resulting from the two disasters, the sediment yields of check-dam basins, and the sediment discharge of the whole basin indicate that recent sediment discharge contains landslide debris that was originated by the Kanto Earthquake that occurred over 80 years ago. Thus, to understand high sediment discharge, it is essential to investigate not only the current basin condition and recent events, but also the landslide history of the basin for at least the previous 100 years.     

Cosmogenic nuclide-based investigation of spatial erosion and hillslope channel coupling in the transient foreland of the Swiss Alps

Transient landscape disequilibrium is a common response to climatic fluctuations between glacial and interglacial conditions. Such landscapes are best suited to the investigation of catchment-wide response to changes in incision. The geomorphology of the Trub and Grosse Fontanne, adjacent stream systems in the Napf region of the Swiss Molasse, was analyzed using a 2-m LIDAR DEM. The two catchments were impacted by the Last Glacial Maximum, LGM, even though the glaciers never overrode this region. They did, however, cause base levels to drop by as much as 80 m. Despite their similar tectonic, lithologic and climatic settings, these two basins show very different responses to the changing boundary conditions. Stream profiles in the Trub tend to be smooth, while in the Fontanne, numerous knickzones are visible. Similarly, cut-and-fill terraces are abundant in the Trub watershed, but absent in the Fontanne, where deep valleys have been incised. The Trub appears to be a coupled hillslope–channel system because the morphometrics throughout the basin are uniform. The morphology of hillslopes upstream of the knickzones in the Fontanne is identical to that of the Trub basin, but different downstream of the knickzones, suggesting that the lower reaches of the Fontanne have been decoupled from the hillslopes. However, the rapid incision of the Fontanne is having little effect on the adjacent upper hillslopes.We tested this interpretation using cosmogenic ¹⁰Be-derived basin-averaged denudation rates and terrace dating. The coupled nature of the Trub basin is supported by the similarity of denudation rates, 350 ± 50 mm ky^− 1, at a variety of spatial scales. Upstream of the knickzones, rates in the Fontanne, 380 ± 50 mm ky^− 1, match those of the Trub. Downstream of the knickzones, denudation rates increase to 540 ± 100 mm ky^− 1. The elevated rates in the downstream areas of the Fontanne are due to rapid incision causing a decoupling of the hillslope from the channel. Basin response time and the magnitude of base level drop exert the principal control over the difference in geomorphic response between the two basins. The timing of the filling of the Trub valley, 17 ± 2 ka, and the initial incision of the Fontanne, 16 ± 3 ka, were calculated, verifying that these are responses to late glacial perturbations. Unique lithologic controls allow for one of the fastest regolith production rates yet to be reported,  380 mm ky^− 1.     

塔里木盆地下古生界碳酸盐岩台缘结构特征及其演化

台缘斜坡带以发育灰泥丘烃源岩和礁滩相储层备受关注,而台地结构样式制约着台缘斜坡带的发育类型和空间展布格局。在地震、测井、岩心、露头等资料的综合分析基础上,研究发现塔里木盆地下古生界发育缓坡型、镶边型、孤立型和淹没型4种碳酸盐岩台地结构样式。同一时期的不同地区台地结构样式存在差异:寒武纪时期,塔中、塔北为进积缓坡型碳酸盐岩台地,而塔西南为退积缓斜坡型碳酸盐岩台地;早奥陶世时期,塔北为退积镶边型碳酸盐岩台地,而塔中、塔西南地区则为加积镶边型碳酸盐岩台地。台地结构在纵向上发育演化的同时,台缘坡折带在平面上也发生迁移变化：寒武纪时期台缘坡折带环绕着西部台地呈向西开口的“U”字型分布;早中奥陶世塔西南地区的台缘斜坡带向盆内迁移,塔中、塘南地区分别发育中古台槽和塘南台缘坡折带;晚奥陶世时期塔里木盆地整体呈现“3个半岛型台地”、“4个台地边缘相带”的沉积格局。塔西南地区寒武-奥陶纪的台缘坡折带、塔中地区早、中奥陶世的中古台槽以及塘南地区奥陶纪台缘斜坡带的发现,对塔里木盆地早古生代沉积格局的重新认识具有重要意义。     

长江三角洲南汇潮滩沉积速率及其影响因素

近100余年来,南汇潮滩尤其是中、高潮滩,以淤涨为主,使岸线迅速向海推进。但潮滩沉积并 非连续,而是以冲、淤相间,长期净淤积的方式进行。潮滩沉积剖面主要由风暴成因的小型层序组成,粗、细 粒交替分别代表风暴与平静天气的产物。潮滩沉积环境的不稳定性使其难以满足两种常用来计算210Pb沉积速率 的方法---CIC （稳定的初始比度） 模型和CRS（稳定的沉降通量） 模型的前提条件。在实验时,如果只选择 代表平静天气沉积的细颗粒层进行210Pb活度分析,则可能得到一组相对符合CIC模型的数据,利用此方法计算 出南汇潮间带环境的平均沉积速率为6.11~6.23 cm/yr。对历史海图数字化建立的数字高程模型（DEM） 分析 表明,中、高潮滩近50余年的平均沉积速率为1.91~2.05cm/yr,不及210Pb沉积速率的一半。造成这种差异的 原因有：（１） DEM法在高程推算过程中使用简单的潮滩纵剖面模型,导致计算的沉积速率偏低;（２）210Pb法受 到沉积过程中强烈的物理混合作用和沉积后的生物扰动、化学迁移作用等影响,使计算的沉积速率偏高。推断 近50余年来,南汇中、高潮滩的沉积速率为4～5cm/yr。