Crustal thicknesses and Poisson's ratios beneath the Chuxiong-Simao Basin in the Southeast Margin of the Tibetan Plateau

In the Southeast Margin of the Tibetan Plateau, low-velocity sedimentary layers that would significantly affect the accuracy of the H-κ stacking of receiver functions are widely distributed.In this study, we use teleseismic waveform data of 475 events from 97 temporary broadband seismometers deployed by ChinArray Phase I to obtain crustal thicknesses and Poisson's ratios within the Chuxiong-Simao Basin and adjacent area, employing an improved method in which the receiver functions are processed through a resonance-removal filter, and the H-κ stacking is time-corrected.Results show that the crustal thickness ranges from 30 to 55 km in the study area, reaching its thickest value in the northwest and thinning toward southwest, southeast and northeast.The apparent variation of crustal thickness around the Red River Fault supports the view of southeastern escape of the Tibetan Plateau.Relatively thin crustal thickness in the zone between Chuxiong City and the Red River Fault indicates possible uplift of mantle in this area.The positive correlation between crustal thickness and Poisson's ratio is likely to be related to lower crust thickening.Comparison of results obtained from different methods shows that the improved method used in our study can effectively remove the reverberation effect of sedimentary layers.

Seismic Technique for Studying Sedimentary Layer: Bohai Basin as an Example

The upper tertiary to quaternary is the main target layer for oil and gas exploitation in China's Mainland, especially crude oil production in the Bohai Basin accounts for approximately 40% of China’s crude oil production. Therefore, a study of the Upper Tertiary to Quaternary has important significance for science and practical applications. In this study, using the receiver function method, Ps and later phase extraction, the sedimentary thickness and an accurate estimate of velocity ratio can be obtained. The technique is simple, its calculation results are unique, and it can be applied to a study of the sedimentary layer. The technique is promising for oil and gas exploration.

Combination Patterns and Depositional Characteristics of Ordovician Carbonate Banks in the Western Tarim Basin,China

The combination patterns and depositional characteristics of the carbonate banks are investigated based on outcrop sections, thin sections, and carbon isotopes of Ordovician in the western Tarim Basin, China. Four carbonate bank combination patterns are deposited in the Ordovician, western Tarim Basin, including： Reef-Bank Complex （RBC）, Algae-Reef-Bank Interbed （ARBI）, Thick-Layer Cake Aggradation Bank （TLCAB）, and Thin-Layer Cake Retrogradation Bank （TLCRB）. All combination patterns show clear periods vertically. The RBC is mainly composed of reefs and bioclastic banks, and the dimension of the RBC depends on the scale of the reefs. Bioclastic banks deposits surround the reefs. The range of the ARBI is determined by the scale of algae-reefs, algae peloid dolomite microfacies and algal dolomite microfacies deposit alternating vertically. TLCAB and TLCRB are deposited as layer-cakes stacking in cycles and extending widely with cross bedding developed. The grains of TLCAB and TLCRB are diverse and multi-source. With the impacting of relative sea level change, biological development and geomorphology, the ARBI, TLCAB or TLCRB, RBC are successively developed from the Lower Ordovician Penglaiba Formation to the Middle Ordovician Yijianfang Formation. The depositional environment analysis of Ordovician indicates that the RBC and ARBI can form effective oil and gas reservoirs, and the TLCAB and TLCRB have the potential to form the huge scale oil and gas reservoirs and to be the crucial targets of exploration for the Ordovician carbonate banks in the future.

Characterization of Sediment from Ourokessoum, North Cameroon: Morphostructural, Mineralogical, and Physicochemical Properties

The present study examines the morphological, physicochemical, and mineralogical specificity of clay sediments in the Hamakoussou Basin with the objective of exploring their potential applications. Field data collection was followed by a series of physicochemical and mineralogical tests on the clay samples. Results show that the clay layers, which range in thickness from 11 - 120 cm, exhibit gray, yellowish, or greenish colors. From a physicochemical perspective, these clay layers are found to be basic with a pH ranging from 8.5 for the higher Hama2 layer to 7.6 for the lower Hama1 layer. The sum of exchangeable bases (S) is medium to high with higher values in the Hama1 layer (53.45 meq/100g) and lower values in the Hama3 layer (17.09 meq/100g). Similarly, the cation exchange capacity (CEC) varies from 62.32 meq/100g for the higher Hama1N4 clay layer to 35.6 meq/100g for the lower Hama1N3 clay layer. Mineralogically, the clay materials are primarily composed of smectites, with illite, kaolinite, calcite, quartz, feldspar, hematite, and goethite also present. This study emphasizes the versatility of clay in various industries and scientific domains. It is known for its impermeability, plasticity, and fossil-preserving capabilities, making it a valuable material for economic, practical, and academic applications.

基于HVSR方法的上海市典型场地特征研究

上海市强震台网获取了2020年5月3日日本九州6.0级地震等多次强震记录。通过对地震记录进行分析处理,分别计算了每个强震台站的H/V谱比曲线,结合上海市地质调查研究院的基岩埋深分布图,得到了每个台站的基阶共振频率与沉积层厚度。结果表明:H/V谱比曲线峰值与沉积层厚度存在明显相关性,并且通过数据拟合建立了上海市沉积层厚度与基阶共振频率的经验公式,绘制了上海市场地基本周期分布图,可以为上海市抗震设防提供一定的参考;厚沉积层场地上地震记录的谱比曲线会出现多个峰值,第二个峰值代表了沉积层的高阶共振频率;通过数据拟合得到上海地区剪切波速与沉积层厚度的经验公式。

基于离散元数值模拟的构造变形机制分析方法——以准噶尔盆地南缘为例

受多期构造运动影响,准噶尔盆地南缘前陆冲断褶皱带具横向东西分段、南北分带,纵向构造叠置的变形特征。但该区构造变形机制及样式的不同认识在一定程度上制约了油气勘探的深入。为探究准南缘新生代以来构造变形机制及其变形过程,本文利用高精度地震、钻井和岩石力学等资料,根据实际地质条件,重点考虑滑脱层的数量、强度及厚度变化,结合滑脱层纵向组合、横向分布范围及同沉积作用、先存构造等因素,共设计了10组模型,并采用离散元数值模拟方法开展了对比实验。实验结果表明,滑脱层强度、厚度及其组合主要控制冲断褶皱带构造纵向叠置关系及构造样式,滑脱层分布及同沉积作用主要控制其横向变形范围,先存构造主要影响后期构造的继承性发育。在此基础上,分段开展了多因素组合模拟实验并与实际地震剖面进行对比,重构了准南缘构造变形过程,揭示了新生代以来其构造变形机制,即先存断裂、古凸起、三套不同性质滑脱层纵向叠置关系和同沉积作用共同控制了西段构造的形成与演化,“下强上弱”“下薄上厚”两套纵向叠置滑脱层控制了中段构造的形成与演化,先存断裂及单套较弱滑脱层控制了东段构造的形成与演化。该方法可为类似的复杂构造变形区提供参考。

四川盆地南部中二叠统茅口组岩溶古地貌恢复及特征

岩溶古地貌是含油气盆地沉积微相类型、分布范围及储层发育的主控因素,恢复岩溶古地貌对指导油气勘探至关重要。基于钻井、测井及地震等资料,采用沉积速率法和地层厚度对比法对四川盆地南部地区中二叠统茅口组顶部不整合界面的剥蚀厚度进行了精确计算,并根据剥蚀厚度的地区差异及古地貌指示,对岩溶古地貌单元进行了进一步划分。研究结果表明:①四川盆地南部中二叠统茅口组顶部主要发育平行不整合,仅在局部地区形成角度不整合。早中二叠世,上扬子地台内部沉积稳定,构造运动较弱,沉积速率法与地层厚度对比法相对更适用于研究区的岩溶古地貌恢复。②研究区中二叠统茅口组顶部剥蚀厚度为0~120m,其中北部剥蚀最强烈,如LG1井区、W4井区代表了岩溶古地貌地势的最高位置,向东南方向剥蚀强度逐渐减弱,地势逐渐降低;剥蚀最薄弱地区位于LS1井东北部,代表了岩溶古地貌地势的最低位置,整体呈现北部高,南部低,东北部最低的地貌格局。③研究区茅口组古地貌特征控制了岩溶作用的发育强度,可划分为岩溶高地、岩溶斜坡、岩溶盆地等3个二级岩溶古地貌单元以及溶峰盆地、溶丘洼地、丘丛谷地、丘丛洼地、丘丛沟谷、峰林平原、残丘平原等7个三级古地貌单元,其中岩溶斜坡易形成良好的储集空间,为油气圈闭的形成奠定了良好的基础,是下一步有利勘探方向。

基于改进广义S变换时频分析的“板状”断控油藏油柱高度预测

塔里木盆地北部坳陷碳酸盐岩断控领域油气资源丰富。断控“板状”油藏油水界面的识别是该类油藏效益开发的关键工作。钻井探测油藏油水界面的成本高、工程实现难度大,而采用地球物理的方法识别油水界面是一种高效措施。文章提出一种基于广义S变换时频分析的应用方法,通过大量过井地震道时频分析结果与开发动态分析数据联合分析,发现地震资料主频随深度/时间的变化与油层厚度具有正相关关系,提出采用地震道时频道集能量包络异常拐点判别油水界面的思路。实验表明,针对“板状”油藏,当油柱厚度OCH<120 m时,分析结果存在不确定性;当120≤OCH≤250 m时,分析结果基本可靠;当OCH>250 m时,油层厚度可靠。应用表明,在富满油田某区某断裂破碎带预测油层厚度主体为200~520 m,与当地开发实际相符,可指导开发实践。

长江流域PHC管桩高质量沉桩施工关键技术分析

本文以武穴港田镇港区盘塘作业区散货码头工程为依托;针对内河长江流域细砂层较厚,PHC管桩沉桩困难,易出现桩身开裂、桩头破损等质量通病问题,结合内河长江流域沉桩施工特点、以往施工经验及现场实际施工情况,开展长江流域PHC管桩高质量沉桩施工关键技术分析研究。通过“一桩一议”分析方法,采用“间歇性复打”施工工艺,形成一套完整内河长江流域PHC管桩沉桩施工质量全周期控制方法。经工程应用表明,Ⅰ类桩比例达到100%,有效解决厚砂层PHC管桩沉桩困难,桩损大等施工难点,取得了良好的社会与经济效益,具有适用性与先进性,可为今后类似工程的建设提供理论依据和技术支撑。

大陆岩石圈挠曲背景下盆山耦合研究进展与展望

盆山耦合研究在大地构造和地球动力学研究中占有重要地位。地貌负载引起的大陆岩石圈挠曲与沉积盆地沉降是盆山耦合的一种重要体现方式。本论文聚焦于挤压背景下大陆岩石圈挠曲盆地与造山带的耦合过程,系统梳理了单个或者多个地貌负载的几何形态、挠曲盆地几何形态以及岩石圈有效弹性厚度(T_(e))三者之间的数学关系。在此基础上,论文介绍了岩石圈挠曲模拟方法在恢复岩石圈刚性程度、造山带演化过程以及盆地沉积沉降方面的具体应用。结合古环境分析与岩石圈挠曲模拟实验,本文提出了一种定量恢复造山带古海拔的新方法。有别于基于温度、压力以及动植物分布与海拔之间关系所建立的传统古高度计,该方法强调在海侵时期地貌负载与沉积盆地间的高度差即为造山带的古海拔。该方法的提出为重建中亚以及其他曾受海侵影响并与岩石圈挠曲相关造山带的古海拔提供了新的思路。论文最后介绍了岩石圈挠曲模拟在定量分析造山带与盆地演化的研究过程中存在的问题与不足,并提出了在探究沉积盆地基底属性、重建岩石圈挠曲相关造山带古海拔以及有关挠曲模拟软件开发方面的新展望。

广东地壳公共速度结构模型建设设想

1研究背景。广东拥有超高密度的高层建筑群、现代化的综合交通运输体系、世界级港口群、空港群,高速公路、铁路、城市轨道交通总里程位居全国前列,具有人口密度高,经济体量大,社会影响广的特点。同时,广东经济最为发达的珠江三角洲地区位于华南沿海地震带中段的构造断陷盆地,盆地内部及边缘区NE向、NW向以及NEE向断裂互相切割且具有多期活动的特点(林纪曾等,1980;Lee and Lawver,1995;魏柏林等,2001);广东近海展布着曾发生多次强震的滨海断裂带,滨海断裂带是南海北部的重要控震构造和发震构造(刘以宣等,1981;赵明辉等,2003,2004;徐辉龙等,2006;孙金龙等,2012;曹敬贺等,2014),2015年发布的《中国地震动参数区划图》曾将珠江口列为7.5级潜在震源区。

鄂尔多斯盆地西南缘长8油层组物源与古沉积环境恢复:来自岩石地球化学的证据

沉积岩的地球化学元素特征记录了重要的沉积和源区构造信息,可用于分析其物质来源及古沉积环境。根据鄂尔多斯盆地西南缘延长组长8油层组14件泥岩及粉砂质泥岩样品地球化学元素分析结果,结合岩心观察资料对其物源及古环境进行系统研究。结果表明,鄂尔多斯盆地西南缘地区长8油层组源区构造背景主要为与大陆岛弧相关的活动大陆边缘,研究区长8油层组物源主要来自于盆地西南缘秦祁褶皱带长英质变质岩、火成岩岩系。结合不同元素丰度、元素比值及沉积标志对古沉积环境的研究结果表明,古气候以半潮湿-半干燥、干热气候条件为主,古温度总体高于15℃及延长期平均温度;长8油层组沉积时期整体水深较浅,水体性质以淡水为主,古氧化还原环境为浅覆水下的氧化环境。有利的古环境条件、充足的物源为浅水三角洲沉积体系的发育提供了有利条件。

大牛地气田DK13井区山2段主力小层优选

大牛地气田位于鄂尔多斯盆地东北部,上古生界断裂基本不发育,DK13井区位于大牛地气田西南部,占地面积约为1/6气田,下二叠统山西组2段(以下简称山2段)为其主力开发层系之一,辫状河三角洲平原沉积特征明显。为了厘清DK13井区山2段沉积特征,优选主力小层,以山2段储层沉积微相为研究对象,分析了岩心、测井资料,指出了该储层主要发育心滩、分流河道、天然堤、废弃河道、分流间湾共5种微相。研究结果表明:①山2段分为山2-1、山2-2两个亚段,并可细分为山2-1-1、山2-1-2、山2-2-1、山2-2-2四个小层,地层垂向上共发育7期河道;②北东方向水体能量充足,心滩密集发育,纵轴长度介于2.5~4.0km,横轴长度介于1.5~2.0km,厚度介于10~14m,南西方向心滩零星分布,规模较小,泥质含量逐渐增多;③山2-1-1、山2-2-1气层厚度普遍超过4m,自然伽马值介于60~75API,泥质含量低于13%,试气效果较好,稳定日产气量在0.9×104m3以上。结论认为:①山2段不同期次砂体厚度差别明显,横向迁移频繁,多被厚层泥质沉积分隔;②自北东至南西,水体能量逐渐减弱,开始水退,河道横向范围逐渐缩小;③山2-1-1、山2-2-1气层发育,试气产量高,可以作为后期措施选井选层的主力小层。

沉积变异区巷道变形特征及厚层锚注控制技术研究

针对沉积变异区巷道围岩应力集中度高、变形破坏严重等问题,本文以赵楼煤矿7303工作面运输顺槽为工程背景,基于现场调研总结归纳了沉积变异区巷道围岩三类变形破坏模式,模拟对比分析了完整岩层与沉积变异巷道掘进过程中矿压显现特征,沉积变异巷道围岩局部应力集中程度高、岩层分界面处易形成离层产生分区破坏,塑性区明显增大;进一步提出厚层锚注控制技术,利用柔性注浆锚杆实现了厚层锚固与注浆改性的有机结合,提出了修复加固方案并进行了工业性试验。研究结果表明:锚杆索支护阻力稳定,巷道围岩变形速度减慢,变形量控制在100 mm以内,裂隙发育在基础锚固层内,巷道控制效果良好。

松辽盆地长岭断陷构造演化及沉积充填特征

通过对长岭断陷岩心、录井、测井等资料的系统分析,结合全区三维地震精细解释,恢复了研究区断陷期岩相古地理面貌,识别出了湖泊、辫状河三角洲、扇三角洲和火山相等4种岩相类型,并进一步划分出了9种亚相和若干种微相。同时,在构造演化分析的基础上,对长岭断陷断陷期的沉积演化过程及充填特征进行了深入研究。研究表明:长岭断陷断陷期整体可划分为初始断陷期、快速断陷期和断陷萎缩期,其内部进一步识别出了火石岭末期、沙河子末期两期局部隆升和营城末期的构造反转。上述6个构造阶段分别对应了断陷初期充填阶段(火石岭期)、断陷初期剥蚀夷平阶段(火石岭末期)、快速断陷期充填阶段(沙河子期)、快速断陷期挤压剥蚀阶段(沙河子末期)、断陷萎缩期充填阶段(营城期)和断陷萎缩期挤压剥蚀阶段(营城末期)。

基于海底沉积层厚度分析的人工鱼礁选址初步研究

人工鱼礁的建设可优化海域生态环境、养护生物资源,促进海洋持续健康发展。人工鱼礁选址是人工鱼礁建设的首要环节,开展人工鱼礁建设工作前必须对人工鱼礁进行科学选址。以大连市长海县大长山岛东北部海域人工鱼礁选址工作为例,使用“SIGPULSEM2电火花震源单道地震”对海域沉积层厚度进行勘测,根据海域各地层沉积厚度分布,结果表明,海域北侧沉积厚度大,不宜进行人工鱼礁建设,海域南侧沉积厚度小,适宜进行人工鱼礁建设。通过潜水调查方式对人工鱼礁海底投放情况进行跟踪调查,验证人工鱼礁建设可依据沉积层厚度进行最适选址。

基于有限断层动力学模型的逆断层—三维层状沉积盆地地震动模拟

近断层效应使得沉积盆地对地震动放大效应更为复杂。本文针对逆断层发震下三维层状沉积盆地地震反应,基于波动谱元法,采用有限断层动力学模型,模拟断层动力破裂、地壳层地震波传播和层状沉积盆地对地震波散射全过程。在此基础上,对比分析了层状和均质沉积盆地对近断层地震动放大效应的影响,讨论了不同断层倾角下层状沉积盆地地震动加速度特性。结果表明:层状沉积盆地PGA空间分布与均质沉积盆地存在较大差异,由于近断层效应和盆地效应,层状沉积盆地地表局部范围竖向PGA大于水平向PGA;90°断层倾角下层状沉积盆地地表地震动放大范围与60°断层倾角结果明显不同,主要集中在盆地中心区域和断层附近,且幅值远小于60°断层倾角下结果;沿断层走向,盆地内地表地震动加速度峰值对应时刻较盆地外延后。

Water storage variations of the Yangtze,Yellow,and Zhujiang river basins derived from the DEOS Mass Transport (DMT-1) model

In general, China is short of water resources and some regions even experience a shortage of daily water supply. This could threaten the stability and economic development of the nation. A study on the water storage variations is especially important for the water management and storage prediction in three largest river basins of China, namely, Yangtze, Yellow, and Zhujiang, where the most dense population and leading economic regions are located. The satellite gravity mission GRACE （Gravity Recovery and Climate Experiment） provides an opportunity to macroseopically identify water （or mass） variations in the Earth＇s system with a spatial resolution of 300-400 km and a temporal resolution of about one month. We use the first release of the DEOS （Delft Institute of Earth Observation and Space Systems） Mass Transport （DMT-1） model based on GRACE data to analyze water storage changes in the three river basins. The DMT-1 model consists of monthly solutions, which are computed using an innovative methodology. The methodology includes, in particular, the application of a statistically optimal Wiener-type filter based on full varianee-covariance matrices of noise and signal. This results in particularly sharp mass variation maps. Taking one monthly solution as an example, we compare the results derived from the DMT-1 model with ones produced with the standard post-processing scheme based on a combination of the de-striping and Gaussian filtering. The comparison shows that the DMT-1 model outperforms the other models and is suitable for the analysis of the mass changes in river basins. A subset of the DMT-1 solutions in the interval between February 2003 and May 2008 is used to estimate the secular trends and seasonal variations for the three river basins. The estimated trends show that the water storage of the Yellow River basin does not have significant changes, while the Zhujiang and Yangtze river basins have a large and statistically significant water storage increase. The estimation of seasonal variations demonstrates that the water storage variations in Yangtze and Zhujiang river basins are almost in the same phase. The amplitude of variations in the Zhujiang River basin is larger than that in Yangtze. No clear annual variations are observed in the Yellow River basin. The observed water storage variations generally coincide with the observations and conclusions presented in the hydrological reports of the Chinese Ministry of Water Resources

陕甘宁盆地陇东地区长8油组厚层非均质砂体的沉积学解剖

通过对延长统长 8段厚层砂岩沉积岩石学和层序地层学研究 ,将其分为两类 ,一类是由多期单一成因的分流河道砂岩叠加构成 ;另一类是由三角洲前缘的水下分流河道、河口坝、坝顶席状砂和滑塌砂等多种沉积微相以不同的组合形式叠加构成。首次提出在“高可容纳空间 ,高沉积通量”背景下 ,只有经过特殊水动力条件 (淘洗 )改造后形成的被我们称之为坝顶席状砂的砂岩才有可能成为相对高孔、高渗的优质储层。

南黄海盆地基底及海相中、古生界地层分布特征

南黄海盆地是大型海相中、古生界和陆相中、新生界两期叠合型盆地,本文根据最新地震资料结合钻井资料及与海陆地质资料的对比研究对盆地内地震层序进行了划分,得到了陆相中、新生界盆地基底即中、古生界海相盆地的顶界埋深、三叠系和上二叠统的残留厚度,推断了陆相层基底地层分布,并根据磁力异常资料推测了海相中、古生界盆地结晶基底埋深,推断了海相中、古生界整体残留情况.下三叠统青龙组和上二叠大隆及龙潭组在南黄海盆地南部坳陷及勿南沙隆起广泛存在,而在北部坳陷的分布则狭窄,中部隆起则由于隆起和剥蚀作用导致这两套地层几乎没有残余.对中-古生界海相盆地和中-新生界陆相盆地的基底特征进行了比较,认为海相中、古生界在南黄海地区区域性存在,海相层厚度分布特征受基底起伏控制,同时受到印支板块运动的影响,中部隆起区是海相中、古生界比较稳定的地区.下古生界可能在南黄海盆地广泛分布,但受资料限制,还难以获知其残余地层的特征.