细粒沉积物层序地层划分方法初探:以东营凹陷樊页1井沙三下-沙四上亚段泥页岩为例

东营凹陷沙三下-沙四上亚段发育了一套厚层的泥页岩,前人研究认为这一套厚层泥岩是经典层序地层学中的湖进体系域(EST),没有做过进一步的细分。随着近年来页岩油(气)研究的深入开展,地质学家们认识到了泥页岩并非整体一套,而是与砂岩一样也具有明显的非均质性,这就要求针对泥页岩等细粒沉积物的研究要进一步精细化。对于泥页岩的层序研究而言,传统(经典)的划分方法完全不适应(依据经典层序地层接触关系、地震反射特征、岩性组合变化等参数),因此迫切需要寻找一种切实可行的方法对泥页岩进行层序精细划分。通过研究,提出了基于T-R旋回理论的GRP层序划分法。该方法以自然伽马曲线(GR)为基础,结合岩相变化分析,充分利用各类地球化学数据以及GR测井在泥页岩层段响应特征和湖平面T-R旋回变化的耦合关系,进行泥页岩中的旋回识别分析。利用该方法,将东营凹陷樊页1井沙三下—沙四上亚段从下至上划分为7个GRP(GR Parasequence)层序,并进一步分析了控制细粒沉积物层序的因素。     

Review on snowmelt runoff simulation in mountain regions,Northwest China北大核心CSCD

Snowmelt runoff is a valuable water resource in Northwest China. In the past few decades, progress has been achieved in snowmelt runoff simulation in mountainous areas, including observation and simulation of snow melt process, improvement and development of distributed snow melt runoff model, and ability for application of snow melt runoff model with temporal and spatial distribution driving data. The development of interpolation algorithm, remote sensing and data assimilation technology provides data support for the widespread application of distributed snowmelt runoff model in northwest mountainous regions of China. Climate warming and economic and social development will further aggravate the contradiction between supply and demand of water resources in the arid regions of Northwest China, which requires higher precision and detail spatial and temporal resolution of snowmelt runoff simulation. Based on the progress and challenges on snowmelt runoff simulation in mountainous regions of Northwest China, following studies need more attention：the mechanism of snow accumulation and ablation, snow cover spatial and temporal distribution monitoring and high precision of snow distribution data acquisition, quantitative climate change impact on river basin snowmelt runoff. © 2022 The authors.     

济阳坳陷探井地质风险评价方法——以陡坡带砂砾岩体为例

济阳坳陷圈闭已进入隐蔽油气藏勘探阶段,当前面临的主要地质风险是不同类型隐蔽油气藏识别及含油气性判断、同一类型隐蔽油气藏的规模等。此文针对勘探重点类型陡坡带砂砾岩体建立探井地质风险评价方法,主要是从成藏地质条件和失利探井两个方面对地质风险的成因进行分析,总结成藏的主控因素,进而确定地质风险评价的地质要素,并通过地质条件和统计分析,对地质要素进行分级,建立分级标准;利用勘探成功率影响程度法,确定权系数,从而建立地质风险评价标准。用2009年已钻探井对评价标准进行检验,评价结果与钻探结果吻合率为80％,取得了较好的应用效果。     

Glacial changes in the Gangdisê Mountains from 1970 to 2016

Based on the revised First Chinese Glacier Inventory(FCGI), the Second Chinese Glacier Inventory(SCGI) and Landsat OLI images for 2015–2016, we analyzed the spatial-temporal variation characteristics of glaciers in the Gangdisê Mountains from 1970 to 2016. The results showed that there were 3953 glaciers with a total area of 1306.45 km~2 and ice volume of ～58.16 km~3 in the Gangdisê Mountains in 2015–2016. Glaciers with sizes of 0.1–5 km~2 and 0.5 km~2 accounted for the largest area and the most amounts of glaciers in the Gangdisê Mountains, respectively. Over the past five decades, the area of glaciers in the Gangdisê Mountains decreased by 854.05 km~2(-1.09%·a~(-1)), accounting for 39.53% of the total glacier area in 1970. The increase in temperature during the ablation period was the most important cause for glacier retreat. Compared to other mountains in western China, the Gangdisê Mountains have experienced the strongest glacial retreat, and the rate of recession has increased in recent years. The decrease of glacier area was mainly concentrated at elevations of 5600–6100 m, and no change in glacier area was observed at elevations above 6500 m. The number and area of glaciers decreased in all orientations in the Gangdisê Mountains except for south-and southeast-oriented glaciers. Among them, north-oriented glaciers suffered the largest loss of glacier area, while glacier retreat saw the fastest in northwest-oriented glaciers. The rate of glacier retreat increased from west to east in the Gangdisê Mountains. The relative rate of glacier area change was the highest in the eastern section of the Gangdisê Mountains(-1.72%·a~(-1)), followed by the middle section(-1.67%·a~(-1)) and the western section(–0.83%·a~(-1)).     

近20年天山地区冰湖变化特征

主要基于Landsat TM/ETM+影像等数据,分析1990-2010 年来天山地区冰湖变化特征及其对冰川融水径流的影响。近20 年来,天山冰湖面积平均以0.689 km²a^-1 或0.8% a^-1的速度扩张,其中一半以上是由东天山(0.352 km² a^-1) 贡献的,其次为北天山,面积年均增率为0.165km² a^-1,西天山和中央天山的面积年均增率最小,分别为0.089 km² a^-1和0.083 km² a^-1。除在相对较低海拔(< 2900 m) 和高海拔(> 4100 m) 范围内冰湖面积出现减少的现象,其他各高度带的冰湖面积均在扩张,其中增率最快的在3500~3900 m之间,平均增速达1.6% a^-1。冰湖扩张是本区气候变暖和冰川普遍退缩共同作用的结果,以中小规模的冰湖(< 0.6 km²) 对冰川退缩响应最为敏感。冰湖扩张能在一定程度上延缓因气候变暖而导致的区域冰川水资源的亏损,每年大约有0.006 Gt 的冰川融水滞留在冰湖中,约占天山冰川年消融量的2‰,但也将加剧本区冰湖溃决洪水/泥石流灾害的频次和强度。     

黄河源区阿尼玛卿山典型冰川表面高程近期变化

阿尼玛卿山位于青藏高原的东缘,是黄河源区冰川分布比较集中的区域。该区域的冰川物质平衡变化研究对于冰川水资源评估及冰川对气候变化响应研究具有重要借鉴意义。通过TerraSAR-X/TanDEM-X数据的干涉测量方法获得阿尼玛卿山区冰川的高分辨、高精度的数字高程模型（DEM）,与SRTM DEM进行差分获得该区域冰川2000年至2013年间的表面高程变化。对比发现：近13 a来该区域典型大冰川表面高程整体均有所下降,唯格勒当雄冰川末端区域冰川表面高程平均下降（4.16±3.70）m,冰舌中部表面高程有所增加,冰川末端区域表碛覆盖范围有所增加;哈龙冰川表面高程从末端往上呈递减下降的趋势,平均下降（8.73±3.70）m;耶和龙冰川表面平均下降了（13.0±3.70）m,但从冰川末端往上1.6 km区段表面高程平均增加约25 m,冰舌中部表面高程下降明显,对比冰川编目数据、Landsat TM图像可知,该冰川在2000年至2009年间发生过跃动,冰川末端位置前进了约500 m。总体来说,即使存在个别冰川前进现象,该区域冰川在近13 a间仍处于退缩状态。