沉积盆地动力学的研究现状、问题与展望

沉积盆地动力学研究沉积盆地在地质历史时期的地质结构特征、成因机制及其对成矿、成藏的控制作用, 是地球动力学研究的重要组成部分.30多年来, 沉积盆地动力学经历了沉积盆地的板块构造分类与构造环境解释、盆地动力学的兴起, 盆地综合建模与盆地系统动力学3个发展阶段; 在沉积盆地的深部构造背景、盆-山关系、沉降机制、充填模式及其对能源、矿产的控制方面取得重要进展.目前, 在对不同层次、不同尺度、不同机制的盆地动力学综合分析, 全3-D和4-D盆地动力学模型的构建与检验, 及学术界与工业界的充分结合等方面面临重要挑战.需解决一系列关键科学问题: 沉积盆地的深部结构、过程与盆地形成; 沉积盆地的构造-气候古地理; 多旋回沉积盆地叠合动力学过程与原型盆地演化; 叠合盆地复合成矿(藏)系统流体运聚及其资源、能源效应等.基于大数据综合集成、多学科交叉渗透、观测技术与分析方法的不断进步与完善, 盆地动力学将在其结构构造、形成演化及其控矿(藏)的4-D综合模型方面取得突破, 并为人类社会、经济发展做出贡献.     

癌症的起源和防治

癌细胞与正常的人体细胞不同。根据体细胞突变理论（SMT）,癌细胞是基因突变的结果。该理论还采用达尔文主义的基本原理,假设癌细胞生长是自然选择下“适者生存”的结果。与此相反,我们采用Margulis的演化理论来解释癌症的起源,并提出癌细胞由遗传而来：癌基因组起源于寄生在原核生物宿主中的细菌;在大约20亿年前的“氧气革命”期间,癌基因组与原核生物基因组因内共生作用而融合;后来宿主演化成为真核生物（原生生物、真菌、植物和动物）,每种真核生物都具有其独特的基因组;经过同样的时间间隔,原寄生细菌基因组则演化成为真核生物内的癌干细胞基因组。当前SMT假设人类基因组的突变导致癌症,但该理论无法识别编码肿瘤生长的基因组序列,也无法解释：突变为何会造成癌细胞失控性生长及复制？癌症为何是一种代谢性疾病？癌症死亡率为何与亚硝酸盐污染有关？中国用不含亚硝酸盐的公共供水源的试验为何竟可以拯救许多癌症患者的生命？SMT没能充分回答许多“神秘”的癌症问题。相反,我们提出的生物演化理论可以回答这些相关事实,包括那些SMT不能充分解释的问题。我们的理论根据是：癌基因组图谱（TCGA）的科学家未能在正常的人类基因组序列中发现突变或未突变的癌基因组。是癌基因组编码了癌细胞的生长及复制和一种不同的代谢模式。我们的理论假设,癌症起源于“休眠中”的癌干细胞因为受亚硝酸盐的影响而被激活,其中一个癌基因组编码了厌氧或缺氧的代谢模式,为癌细胞的生长及复制提供能量和生物量,其他基因组则编码了癌细胞的失控性生长及复制和其他癌症特征。亚硝酸盐以10-9 级别的浓度干扰人体正常的代谢和复制等机能。事实说明,亚硝酸盐可被定义为一种毒药。识别慢性中毒的困难可以用孟加拉国公共供水造成的砷中毒作为例证。癌症应被视为由亚硝酸盐中毒引起的疾病来进行治疗是一个假说,它可以解释为什么当中国部分地区的正常公共供水改用标准化深井水（SDWW）时,癌症死亡率可以减半。这个假说需要另一个假设来解释亚硝酸盐中毒并不影响所有饮用公共供水的人,而只影响其中一部分人。我们必须假设癌症的产生是由于干细胞,其中包括一个癌干细胞,被召唤去以修复细胞的损伤。将这些打破常规的假说放在一起,很多专家认为我们的生物演化理论是天方夜谭而不予理会。实际上,这个假说已由中国过去的SDWW实验所证实。一些医院的试验也证实,若癌症晚期患者每天饮用不含亚硝酸盐的水,癌症可以被治愈。我们对癌症晚期不可治愈这一论断提出质疑,并假定癌症是慢性亚硝酸盐中毒所致。我们呼吁其他科学家进行实验和临床试验来验证这一假说,使至少一半的晚期癌症患者,当他们的饮用水供应源不含亚硝酸盐时,可以被治愈。与此同时,我们应该将过去半个世纪以来献身医学的科学家们的成果,整合为一个“新的体系”。     

安阳上第三系化学矿物指标显示物源区大地构造

南水北调（中线）安阳主干渠段施工过程中开挖出大量成熟度低且受近源构造影响较大的河湖相沉积岩。对现场采集的上第三系岩石样品开展了化学成分、 岩石骨架成分测试。利用Dickinson法和化学指标法, 研究得到安阳主干渠段西部物源区属于被动陆缘, 在上新世晚期向活动陆缘变化的认识。同期构造活动强烈的克什米尔N—J引水隧洞段的沉积岩, 属于岛弧和活动陆缘的大地构造背景。本文结果丰富了构造稳定和活跃区新近纪沉积构造背景认识, 可为喜马拉雅运动以来不同构造活动背景下的岩石组分和化学指标特征提供参考。     

海南岛海风演变特征的观测分析

本文利用2012年海南岛19个常规气象站、5个海岛站的逐时资料以及海口站的探空资料,对海南岛海风的时空演变特征及在不同天气条件下海风发展的特征进行了统计分析,结果表明:2012年全年海南岛的海风多发生于春、秋季,频率分别为40%和33%,冬季最少(约为19%),尤其是一月,大部分站点均不足10%。夏季海风出现时刻较早;南部沿海海风结束时间晚于北部沿海;冬季海风开始得较晚,南部海风结束时间早于北部沿海。海风平均持续时间约为10 h。沿海站的海风风速主要集中在3~6 m·s~(-1),且最大风速值出现在春季,除琼山、海口站外,最大海风强度多出现于春夏季。内陆站中部山区附近海风出现频率较高、开始时刻较早、持续时间较长、强度也较大。海风向内陆的传播距离至少为70 km;海风易发生在阴天,其次为多云天气,少云日的海风最少。     

成像测井在台缘斜坡礁滩微相研究中的应用——以土库曼斯坦阿姆河右岸中部卡洛夫阶—牛津阶为例

以成像测井资料为基础,开展了土库曼斯坦阿姆河右岸中部的中上侏罗统卡洛夫阶—牛津阶台缘斜坡礁滩沉积微相研究。首先利用岩心、薄片等资料对成像测井进行标定,在成像测井上识别出障积礁、粘结丘、高能生物碎屑滩、低能生物碎屑滩、低能砂屑滩、礁(滩)间和斜坡泥等7种沉积微相。然后通过对不同类型沉积微相的成像测井响应特征进行研究,建立了研究区碳酸盐岩成像测井相模式,主要包括亮斑相、暗斑相、低阻交错层状相、低阻变形层状相、互层相、块状相等6类,并以此为依据进行了连续的单井成像测井相划分与沉积微相解释。最后对沉积微相与储层物性关系进行了研究,认为研究区卡洛夫阶—牛津阶储层主要为裂缝-孔隙型礁滩储层,有利于储层发育的沉积微相主要为高能生物碎屑滩、低能砂屑滩、障积礁、低能生物碎屑滩和粘结丘,礁(滩)间和斜坡泥微相的岩性相对较致密,储层一般不发育。     

下刚果盆地白垩系碳酸盐岩储层沉积模式与储层预测

下刚果盆地下白垩统碳酸盐岩沉积区位于海底地形受盐层影响较大的地区,呈现出多级坡折的特征,对该区下森贾组(Lower Sendji Fm.)沉积储层的预测难度增大。运用层序地层学理论和混合能环境的沉积模式,剖析了邻区M油田下森贾组储层类型和成因演化特征,提出两级坡折的古地貌是因盐运动和碳酸盐选择性生长而形成。通过此地貌对海平面的独特响应,建立了研究区下森贾组低水位和高水位体系域两种不同的沉积模式。借助Opend Tect软件的层序结构解析技术,进行研究区下森贾组沉积旋回韵律体的自动追踪。预测下刚果盆地研究区的碳酸盐岩储层在下部的低水位域和海进体系域可能更发育,钻探结果证实下森贾组碳酸盐岩储层确实发育于下部的低水位域和海进体系域。     

The Effect of Organic Carbon-Iron Oxide Association on the Preservation of Sedimentary Organic Carbon in Marine Environments

Understanding the mechanisms responsible for long-term storage of organic carbon (OC) in marine environment is important for studying the marine carbon cycling and predicting how the global carbon cycle will respond to climate change. It is estimated that more than 20% of the OC in marine sediments is associated with iron oxides and thus these complexes are one of the most important factors in the long-term storage of OC. The OC-iron oxide (OC-Fe) association can be formed through either adsorption or co-precipitation, but the dominant mechanism of OC-Fe association in marine environments is co-precipitation. The combination of OC from different sources with iron oxides is selective. Iron oxides preferentially combine with marine OC in most marine environments, but in estuarine delta regions they prefer terrestrial OC. Due to large inputs of terrestrial materials, high primary production and frequent re-suspension, estuarine and marginal seas are suitable sites for OC-Fe association studies, which should be emphasized in the future.     

Sequence stratigraphy,sedimentary facies and reservoir quality of Es4s,southern slope of Dongying Depression,Bohai Bay Basin,East China

Thin-bedded beach-bar sandstone reservoirs are common in the Eocene Shahejie Formation (Es4s) of Niuzhuang Sag, along the southern gentle slope of the Dongying Depression. Here we report on the link between sequence stratigraphy, sedimentary facies and diagenetic effects on reservoir quality. Seismic data, wireline logs, core observations and analyses are used to interpret depositional settings and sequence stratigraphic framework. Petrographic study based on microscopic observation of optical, cathodoluminescence (CL), confocal laser scanning (LSCM) and scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses were used to describe the fabric, texture, allogenic and authigenic mineralogy of these highly heterogeneous sandstone reservoirs. The Es4s interval is interpreted as third-order sequence, composed of a lowstand systems tract (LST), a transgressive systems tract (TST) and a highstand systems tract (HST). On the fourth order, twenty-nine parasequences and seven parasequence sets have been identified. Sand bodies were deposited mainly in the shoreface shallow lake beach-bar (clastic beach-bar), semi-deep lake (carbonate beach-bar) and the fluvial channels. The depositional and diagenetic heterogeneities were mainly due to the following factors: (1) fine grain size, poor sorting, and continuous thin inter-bedded mud layers with siltstone/fine-sandstone having argillaceous layers in regular intervals, (2) immature sediment composition, and (3) even with the dissolution of grains and several fractures, destruction of porosity by cementation and compaction. Secondary pores from feldspar dissolution are better developed in sandstones with increased cementation. Grain coating smectite clays preserved the primary porosity at places while dominating pore filling authigenic illite and illite/smectite clays reduced permeability with little impact on porosity. Due to the high degree of heterogeneity in the Es4s beach-bar interval, it is recognized as middle to low permeable reservoir. The aforementioned study reflects significant insight into the understanding of the properties of the beach-bar sands and valuable for the comprehensive reservoir characterization and overall reservoir bed quality.     

Sedimentary and residual gas geochemical characteristics of the Lower Cambrian organic-rich shales in Southeastern Chongqing,China

To study the sedimentary environment of the Lower Cambrian organic-rich shales and isotopic geochemical characteristics of the residual shale gas, 20 black shale samples from the Niutitang Formation were collected from the Youyang section, located in southeastern Chongqing, China. A combination of geochemical, mineralogical, and trace element studies has been performed on the shale samples from the Lower Cambrian Niutitang Formation, and the results were used to determine the paleoceanic sedimentary environment of this organic-rich shale. The relationships between total organic carbon (TOC) and total sulfur (TS) content, carbon isotope value (δ¹³C_org), trace element enrichment, and mineral composition suggest that the high-TOC Niutitang shale was deposited in an anoxic environment and that the organic matter was well preserved after burial. Stable carbon isotopes and biomarkers both indicate that the organic matter in the Niutitang black shales was mainly derived from both lower aquatic organisms and algaes and belong to type I kerogen. The oil-prone Niutitang black shales have limited residual hydrocarbons, with low values of S₂, I_H, and bitumen A. The carbon isotopic distribution of the residual gas indicate that the shale gas stored in the Niutitang black shale was mostly generated from the cracking of residual bitumen and wet gas during a stage of significantly high maturity. One of the more significant observations in this work involves the carbon isotope compositions of the residual gas (C₁, C₂, and C₃) released by rock crushing. A conventional δ¹³C₁–δ¹³C₂ trend was observed, and most δ¹³C₂ values of the residual gases are heavier than those of the organic matter (OM) in the corresponding samples, indicating the splitting of ethane bonds and the release of smaller molecules, leading to ¹³C enrichment in the residual ethane.     

内蒙古阿巴嘎旗必鲁甘干钼铜矿床成矿流体演化与成矿机制

必鲁甘干钼铜矿床位于内蒙古阿巴嘎旗境内,二连-东乌旗成矿带东段,自2007年发现以来,已探明钼金属量已超过16万吨,达到大型规模。矿床赋存于印支期花岗斑岩和二叠系上统林西组接触带附近,含矿带呈NNE向展布,向SE缓倾。必鲁甘干钼铜矿床成矿阶段可划分为早、主、晚三个阶段,早阶段以硅化和钾长石化蚀变及浸染状和星点状矿化为特征,矿化较强;主阶段以硅化和绢云母化蚀变和发育乳白色含矿石英脉为特征,矿化很强;晚阶段以硅化、碳酸盐化、青磐岩化和粘土化蚀变以及发育石英方解石细脉为特征,矿化较弱。石英中流体包裹体类型主要有富液相水溶液包裹体(L型)、富气相水溶液包裹体(V型)和富CO_2包裹体(C1和C2型)。早阶段发育大量L型和少量C1型包裹体,主阶段发育大量L型和C1型以及少量V型和C2型包裹体,晚阶段主要发育L型包裹体,个别样品发育少量C1型包裹体。早、主、晚阶段均一温度分别为210~354℃、182~351℃、128~312℃,盐度分别为3.6%~9.2%NaC leqv、2.6%~9.2%NaC leqv、2.8%~9.6%NaC leqv。主阶段成矿温度、压力为232~269℃、0.54~1.55kbar;三个阶段成矿深度分别约为8.1~5.8km、5.7~5.5km、3.9~2.6km。从早阶段到晚阶段,成矿流体由中温、中等盐度、富CO_2的NaCl-H_2O-CO_2体系向中低温、低盐度、贫CO_2的H_2O-NaC l体系演化。成矿流体在演化过程中由于周期性压力脉动而导致发生流体不混溶,其可能是成矿元素发生聚集、沉淀形成矿床的重要机制。由必鲁甘干钼铜矿床围岩蚀变("贫水蚀变")、成矿流体成分(NaCl-H_2O-CO_2体系)和成矿深度(主阶段成矿深度约5.7~5.5km)推测其属陆内环境斑岩矿床。