An intelligent automatic correlation method of oilbearing strata based on pattern constraints:An example of accretionary stratigraphy of Shishen 100 block in Shinan Oilfield of Bohai Bay Basin,East China

Aiming at the problem that the data-driven automatic correlation methods which are difficult to adapt to the automatic correlation of oil-bearing strata with large changes in lateral sedimentary facies and strata thickness,an intelligent automatic correlation method of oil-bearing strata based on pattern constraints is formed.We propose to introduce knowledge-driven in automatic correlation of oil-bearing strata,constraining the correlation process by stratigraphic sedimentary patterns and improving the similarity measuring machine and conditional constraint dynamic time warping algorithm to automate the correlation of marker layers and the interfaces of each stratum.The application in Shishen 100 block in the Shinan Oilfield of the Bohai Bay Basin shows that the coincidence rate of the marker layers identified by this method is over 95.00%,and the average coincidence rate of identified oil-bearing strata reaches 90.02% compared to artificial correlation results,which is about 17 percentage points higher than that of the existing automatic correlation methods.The accuracy of the automatic correlation of oil-bearing strata has been effectively improved.

Geochemical Properties and StratigraphicalCorrelation of Frasnian-Famennian TransitionalStrata in Wuzhishan Section

The qualities of petrology and paleobiology in Wuzhishan Section are studied. Several geo-chemical anomalies are recognized, such as: high rare earth element content, high pyrite content and Ni anomalies. It could be correlated with Nandong Section in Xiangzhou County and the F/F boundary could be determined according to Ni anomalies. The results of the study indicate that the geochemical anomaly plays an important role in stratigraphic correlation in non-fossil stratum.

Stratigraphical Time——Correlation and Mass Extinction Event Near Permian——Triassic Boundary in South China

Shaw's method used to correlate 40 sections across the Permo-Triassic boundary in South China is applied in the paper. Two steps are adopted to get an Integral Composite Section (ICS) by synthesizing these data : First , South China is divided into five areas and composite section developed for each area . Then the second step . the Changxing composite section is regarded as a composite standard (CSRS) while the ICS is produced by matching the CSRS with composite sections of the other areas. Three biozones in the Changxingian and two biozones in the Griesbachian can be discerned on the basis of computing Z values in the ICS. These biozones are marked by the Z values which quantitatively represent their time ranges ; therefore , they may increase accuracy of stratigraphic time correlation . The mass extinction at the end of the Permian is an abrupt event that is supported by the relative rate of extinction near the P/T boundary . About 90% of invertebrate species died out by the end of the Permian . The duration of the mass extinction is rather short ,approximately 0.018Ma .

The Low Lake-Level Record according to the Selin Co Stratigraphical Basis and Multi-Proxies during the Last Glacial Maximum in the Central Tibetan Plateau

Objective The lake levels in the eastern and southern Asia are regarded as low lake-level owing to precipitation decreasing based on the records of lake-level fluctuation in the continental interior lakes since the last glacial maximum（LGM）（14C 18±1 kaBP,since 20 kaBP）in the Central Asia.Higher lake-level appeared in the transition belt between western Kunlun Mountain and the central Tibetan Plateau.

ENVIRONMENTAL EVOLUTION OF ORDOS DESERT IN CHINA SINCE 1.1MA B. P. AS INDICATED BY YULIN STRATIGRAPHICAL SECTION AND ITS GRAIN-SIZE ANALYSIS RESULTS

Yulin section is a typical sedimentary record for reflecting the environmental evolution of Ordos Desert, China in the past 1.1Ma. By analyzing its sequence and grain-size composition some views have been put forward in this paper as follows. The layers of sand, loess and palaeosol in Yulin section were respectively formed by wind and the pedogenesis on parent material of the sand and loess. Since 1.1Ma B. P., Ordos Desert has alternately experienced 11 stages of shifting dunes under extreme cold-dry climatic environment, 7 stages of fixed and semi-fixed dunes and 8 stages of dust (loess) under cold-dry climatic condition; and the pedogenesis environment under 15 times of warm-humid climate and 3 times of temperate-humid climate (brownish-drab soils and black soils formed respectively). The aeolian sand had already existed in Ordos Desert at latest by 1.1Ma B. P., and from that time on it has undergone a series of alternative processes of shifting sands, fixed and semi-fixed dunes, loess and soils. Ordos Desert has been situated in the transitional belt of the Mongolian High Pressure and margin of the southeast summer monsoon since 1.1Ma B. P., and influenced repeatedly by migration of the lithofacies belts of shifting sands, fixed and semi-fixed dunes, loess and soils, which have been caused by the climatic fluctuations of glacial and interglacial periods.

Vote-Based Feature Selection Method for Stratigraphic Recognition in Tunnelling Process of Shield Machine

Shield machines are currently the main tool for underground tunnel construction. Due to the complexity and variability of the underground construction environment, it is necessary to accurately identify the ground in real-time during the tunnel construction process to match and adjust the tunnel parameters according to the geological conditions to ensure construction safety. Compared with the traditional method of stratum identifcation based on staged drilling sampling, the real-time stratum identifcation method based on construction data has the advantages of low cost and high precision. Due to the huge amount of sensor data of the ultra-large diameter mud-water balance shield machine, in order to balance the identifcation time and recognition accuracy of the formation, it is necessary to screen the multivariate data features collected by hundreds of sensors. In response to this problem, this paper proposes a voting-based feature extraction method (VFS), which integrates multiple feature extraction algorithms FSM, and the frequency of each feature in all feature extraction algorithms is the basis for voting. At the same time, in order to verify the wide applicability of the method, several commonly used classifcation models are used to train and test the obtained efective feature data, and the model accuracy and recognition time are used as evaluation indicators, and the classifcation with the best combination with VFS is obtained. The experimental results of shield machine data of 6 diferent geological structures show that the average accuracy of 13 features obtained by VFS combined with diferent classifcation algorithms is 91%;among them, the random forest model takes less time and has the highest recognition accuracy, reaching 93%, showing best compatibility with VFS. Therefore, the VFS algorithm proposed in this paper has high reliability and wide applicability for stratum identifcation in the process of tunnel construction, and can be matched with a variety of classifer algorithms. By combining 13 features selected from shield machine data features with random forest, the identifcation of the construction stratum environment of shield tunnels can be well realized, and further theoretical guidance for underground engineering construction can be provided.

A Glance on the Mineral Deposits and Stratigraphic Sequential Variations and Structures in Different Sections of Indus Basin (Pakistan): New Titanosaurian Sauropod Dinosaurs from the Latest Maastrichtian Vitakri Formation of Pakistan

Indus basin hosts many significant mineral deposits like gypsum and cement raw materials, gemstones, iron, coal, marble, dimension and construction stones, petroleum and water resources, world class pink salt and other many minerals in different regions which need further exploitation and development. The construction of new water dams in different regions are vital (for availability of cheap electricity), because of available barren and fertile lands and wastage of water as flood. Further the installation of more cement industries in different regions of Indus Basin especially in middle Indus (Sulaiman Range where gypsum, clays and limestones can be available via belt) can increase export to receive more foreign exchange and make local cement cheap for the sustainable development of Pakistan. 31 stratigraphic sequential sections at different sections of Indus basins are presented to know the variation and local stratigraphy. Further here three new titanosaur taxa are being described. Saraikimasoom is based on snout;Gspsaurus, (Maojandino), Nicksaurus and Khanazeem are based on cranial, vertebral and appendicular elements;Balochisaurus, Marisaurus, Pakisaurus, and 3 new genera and species Imrankhanhero zilefatmi, Qaikshaheen masoomniazi and Ikqaumishan smqureshi based on vertebral and appendicular elements;and Sulaimanisaurus and Khetranisaurus based on only caudal vertebrae. Although Pakistani Titanosaurians seem to be proliferated found from one horizon of Vitakri Formation just below the K-Pg boundary they have a wide range of diagnostic features and key elements among titanosaurs which can be used for comparison and phylogenetic analyses with broad updated character data set of titanosaurs.

鄂尔多斯盆地含铝岩系天然气成藏主控因素与勘探启示

基于野外露头、岩心、录井、测井、试气及分析化验等资料,采用天然气成藏与铝土岩成矿一体化研究方法,分析鄂尔多斯盆地含铝岩系有效储层发育控制因素、煤系烃源岩与含铝岩系的源储配置关系,构建天然气成藏模式,对煤下含铝岩系天然气勘探潜力进行评价。研究表明:(1)鄂尔多斯盆地含铝岩系的有效储层主要为一水硬铝石含量超过75%,具有多孔状残余豆鲕、碎屑结构的蜂窝状铝土岩,溶蚀孔为主要储集空间;(2)铝土岩储层形成模式为夷平化作用提供含铝岩系发育的物质基础、岩溶古地貌控制含铝岩系发育、陆表淋滤作用改善储集性能;(3)晚石炭世—早二叠世,受湿热气候环境和海平面变化控制,古陆或古岛边缘的相对低洼带发育典型的煤-铝-铁三段式地层结构;(4)煤系烃源岩广覆式生烃,天然气在煤下含铝岩系储层富集,为源下成藏;(5)中国华北陆块的上石炭统—下二叠统含铝岩系气藏呈透镜状点群式聚集,勘探潜力大,有望成为华北克拉通上古生界重要的天然气勘探新领域。

西准噶尔构造带包古图地层小区上泥盆统红山梁组的建立及地质意义

西准噶尔构造带包古图地层小区白碱滩北红山梁剖面上新发现一套晚泥盆世红色“硅质岩、粉砂质硅质岩、凝灰质硅质岩”海相沉积组合,与上覆包古图组深灰色—灰黑色含碳粉砂岩呈整合接触。经区域对比确认,该套地层显著有别于研究区乃至整个西准噶尔构造带地层分区已发现的全部上泥盆统各组岩石地层,符合“野外可识别、界面可区别、区域可对比、图面可表达”的原则,据此新建红山梁组。本次于红山梁组枕状玄武岩、玄武岩、安山岩中分别获得365.9±5.0Ma、370.6±7.4Ma和374.6±3.6Ma的LA-ICP-MS锆石U-Pb年龄,佐证其时代为晚泥盆世。红山梁组与包古图组连续沉积之确认,消除了包古图组老于希贝库拉斯组这一存疑,建立了完整的下石统地层序列,新增了包古图地层小区泥盆纪的沉积记录,为区域沉积与构造演化研究提供了新资料。

环太湖地区文化景观的时空层积与特征解译研究——以常州为例

太湖地区以太湖为中心,形成碟形洼地,位于长江三角洲的南部。常州作为太湖平原西北部的区域中心,是早期有人类开发历史记载的重要地区,自古即为运河沿线重要的交通枢纽。通过系统梳理文化景观特征与时空演变,为现代文化景观的保护传承与发展提供理论基础。以地域文化景观这一视角重新审视常州地区,将其理解为融合了自然系统与人文系统的层状体系复合系统,借助文化景观的研究思路,以朝代更迭为时间线索,从历时性、共时性两个维度逐层揭开常州地域文化景观体系中各要素的发展情况,探索古代人地关系的动态演变,并从时空层积、空间特征、关联性内因三个方面进行分析解译。在大运河文化带战略框架下和在快速城镇化进程中,为沿运城市的文化复兴和高质量城乡营建提供一定借鉴意义。

渤海湾盆地沾化凹陷古近系沙三下亚段旋回地层学分析及地层划分

湖相细粒沉积多具有连续性,能记录和保存显著的天文旋回信号,是进行天文旋回分析的理想地层。通过对渤海湾盆地沾化凹陷重点井沙三下亚段自然伽马数据进行MTM频谱分析和FFT进化谐波分析,建立了“浮动”天文年代标尺,并在单井上进行了天文旋回地层划分及连井地层对比,为全区搭建了地层格架。研究结果表明:(1)渤海湾盆地沾化凹陷沙三下亚段记录了显著的天文旋回信号,匹配出最优沉积速率为9.0×103cm/Ma;由长偏心率、短偏心率、斜率和岁差周期产生的旋回地层厚度分别为42.3 m,9.0 m,2.4~4.7 m和1.3~1.9 m;(2)沙三下亚段比较稳定的记录了6个长偏心率旋回、25个短偏心率旋回,可将短偏心率曲线作为地层划分依据来进行高精度地层对比。(3)运用天文旋回理论进行岩相发育规律、岩相空间配置关系的预测,可为湖盆沉积中心页岩油气地质“甜点”的精细勘探提供依据。

福建永安湍石楼前组地层特征及年代依据

在永安南部湍石一带发现一套变质火山碎屑岩,岩石总体变形较弱、变质较浅,原岩结构、构造多有保留。主要岩石类型为变质英安质晶屑凝灰岩。火山喷发作用表现为空落相,呈现较强的火山活动特征。研究区楼前组与长汀张地楼前组剖面对比,区内层位仅相当于张地楼前组下段。LA-ICP-MS锆石U-Pb同位素测年样中的锆石CL图像晶形发育好,韵律环带清晰,且Th/U比值大,为0.58~4.85,均为岩浆锆石的特点。锆石U-Pb谐和年龄为(754.8±3.3)Ma,代表了变质火山岩的成岩年龄,说明了楼前组形成地质时代为南华纪。

论羌塘含油气盆地关键地层划分对比问题

羌塘含油气盆地勘探程度相对较低,一些关键地层的时代归属与划分对比尚存较大的争议,这制约了盆地石油地质条件评价与含油气系统分析。基于近年来在羌塘盆地获得的生物地层、年代地层、沉积层序、盆地演化等方面的最新资料,结合前人的研究基础,重点对制约含油气盆地分析的关键地层时代归属问题开展了综合分析与客观评述。取得的主要认识包括:(1)新的同位素年代学资料证实,羌塘盆地存在前寒武系变质岩结晶基底,古生界基底埋深可达7~15 km,中生界沉积超覆在古生界褶皱系之上;(2)那底岗日组时代归属为晚三叠世,而不是早—中侏罗世;(3)南羌塘古油藏白云岩属于上三叠统,古油藏白云岩很可能“异地无根”,与布曲组为构造断裂接触;(4)南羌塘毕洛错油页岩时代归属为早侏罗世;(5)雀莫错组原定义为中侏罗统,研究证实其时代归属为早—中侏罗世;(6)胜利河—长蛇山油页岩Re-Os同位素定年及生物化石资料证明其为下白垩统海相地层;(7)同位素年代学及野外露头剖面资料证实,康托组与唢呐湖组为同期异相地层。羌塘盆地地层学研究新进展为完善盆地地层划分对比方案,乃至盆地含油气系统分析与盆地资源潜力评价提供了新的依据。

海上稀疏井区高精度地层格架约束下的地震沉积学刻画——以东海盆地西湖凹陷中央背斜带X区块古近系花港组为例

海上工区面积辽阔,单井资料匮乏,花港组内部横向上的沉积微相界定存在争议、纵向上的沉积演化规律不明。为充分挖掘现有井、震资料的地质解释潜力,选取东海盆地西湖凹陷中央背斜带X区块古近系花港组为研究对象,提出了井-震小波变换建立高精度等时地层格架、井点沉积相标志定相类型、分频RGB属性刻画沉积相展布以及古地貌恢复辅助沉积相演化规律分析的地震沉积学解释技术。研究结果表明:(1)测井-地震小波变换结果有较好的一致性,可将研究区花港组分为花港组上段(花上段)3个(H1—H3)和花下段5个(H4—H8)四级旋回,并在此基础上建立高精度等时地层格架。(2)根据岩心相、测井相和地震相相互印证,确认研究区花港组沉积期为辫状河三角洲沉积环境。分频振幅属性验证不同厚度砂岩层在15,30和45 Hz单频体的振幅响应明显,采用分频RGB属性融合可在平面凸显不同沉积体的边界。(3)研究区H1和H2旋回整体为三角洲前缘沉积,H3—H6旋回为浅水背景下的三角洲平原-前缘沉积,H7和H8旋回为辫状河三角洲平原沉积,砂层组沉积相垂向演化受控于物源供给、相对湖平面高低和古地貌形态。在井-震时频分析建立等时地层格架基础上,通过相关性分析优选属性进行RGB融合能够凸显不同厚度砂岩的展布,减少了人为主观因素的影响,提升了沉积体边界的识别能力,可为其他井网稀疏地带沉积相刻画提供借鉴。

碳酸盐工厂的精细刻画:定量化重建视角

【意义】碳酸盐工厂为碳酸盐岩沉积体系提供了物质基础,与海洋演化、元素循环、表生地质过程等密切相关,是反映地球系统演化的重要环节。因此,定量化表征碳酸盐工厂及其主控因素是深入理解碳酸盐岩所记录的地质信息的关键。【进展】总结了半定量—定量表征碳酸盐工厂的研究方法进展,结合对沉积过程正演模拟方法的介绍,从定量重建的角度为精细刻画碳酸盐工厂提供了思路。【展望】针对碳酸盐工厂的研究,应在传统碳酸盐岩沉积学的基础上加深对其主控因素的定量评估,特别是直接影响生态的因素。但在套用基于碎屑岩沉积体系所建立的定量分析方法时,需要考虑碳酸盐岩与碎屑岩的差异,并进一步完善适用于碳酸盐岩的模型和分析方法。此外,在应用地球化学指标反演碳酸盐工厂及其主控因素时,要加强对成岩作用改造程度的定量评估,以降低成岩作用对地球化学信号的影响。而在开发和应用新的碳酸盐岩地球化学代用指标时,需明确其赋存或分馏机理,从而更准确地解读其所反映的古气候和古环境信息。同时,在利用沉积过程正演模拟研究工厂的演化和生产机制时,需评估从现代环境中获取的参数在深时地质记录中的适用性,并在建模过程中考虑早期成岩作用及海水化学演化的影响。

珠三坳陷珠江组一段沉积体系演化过程及其控制因素

珠江组一段沉积时期是珠三坳陷沉积体系演变的重要时期,由早期的大范围三角洲沉积体系演化为晚期的浅海陆架沉积体系,对其演化过程及控制因素展开研究,不仅有利于揭示海侵过程中沉积体系演化过程,而且对浅海陆架有利沉积相带预测具有指导意义。综合利用岩心、测井以及高分辨率三维地震资料,建立了珠三坳陷珠江组一段四级层序地层格架,通过地质-地球物理结合方法查明了珠江组一段沉积体系的时空演化特征,并讨论了沉积演化的主控因素。研究表明:珠三坳陷珠江组一段可划分为PS1、PS2、PS3、PS4共4个四级层序。PS3和PS4时期主要发育三角洲前缘沉积,具有水下分流河道、分流间湾、河口坝和远砂坝等沉积微相组合;PS1和PS2时期以浅海陆架沉积体系大规模发育为特征,在研究区西部发育潮流砂脊,东部发育滨外砂坝。珠三坳陷沉积体系的平面展布以及垂向演化受相对海平面变化、物源供给强度、构造沉降与古地貌等综合控制。水下分流河道、潮流砂脊与滨外砂坝等微相砂岩占比高且物性好,为油气储集的有利沉积相带。

四川广元羊木-岩洞地区震旦纪-寒武纪界线地层序列及构造-沉积演化

绵阳-长宁拉张槽的形成机制及时间尚存在巨大争议,严重制约了灯影组油气勘探的部署。为更好地对拉张槽深水地层提供时代约束,深化拉张槽构造-沉积演化认识,基于露头描述、薄片观察、碳同位素测试,对广元地区4个露头剖面开展综合地层对比和沉积环境分析。岩石学及碳同位素特征表明,研究区实测4条野外露头剖面从下到上可划分为4个岩性段(Ⅰ~Ⅳ):岩性段Ⅰ为薄层泥质灰岩夹泥质白云岩条带,对应陡山沱组三段Shuram-Wonoka负偏段地层;岩性段Ⅱ以黑色页岩为代表,可对比陡山沱组四段;岩性段Ⅲ为块状白云岩-硅质岩序列,属于灯影组同期地层;岩性段Ⅳ以薄板状硅质岩为特征,相当于麦地坪组。其中,灯影组二段早期—麦地坪期,研究区从块状白云岩逐步过渡为薄板状硅质岩,见垮塌体及滑塌揉皱,指示台地转换为斜坡-盆地沉积环境。这种加深的沉积趋势与中上扬子台地相区变浅至暴露的过程完全相反,指示断裂活动影响下快速沉降的过程。

鄂尔多斯盆地西南部古构造指示的构造-沉积过程及砂岩型铀成矿意义

鄂尔多斯盆地自晚中生代以来长期处于多个板块汇聚的中心,在多期构造作用下,引起了盆地内部地层的变形和叠加。因此,通过恢复鄂尔多斯盆地西南部下白垩统不同地质历史时期的古构造特征,可以更好地理解该地区的构造-沉积与铀成矿过程。文章利用钻孔分层数据和地震剖面解释成果,采用了单一岩性逐步回剥的算法进行地层去压实校正,参考了前人的剥蚀量数据,从而恢复了鄂尔多斯盆地早白垩世末的古构造特征。早白垩世末的古构造图显示,在该时期下白垩统中并不存在现今的天环坳陷结构,华池环河组的顶面古构造特征与下部层位相比发生了显著变化。这些现象表明,华池环河组和罗汉洞组之间存在明显的二级层序界面,其转变的动力背景可能源自六盘山裂谷盆地的初始裂陷和相应的岩浆侵位作用。天环坳陷结构的初步形成可追溯到晚侏罗世末的挤压改造,在中新世晚期再次经历了叠加改造并最终定型。研究区的古构造条件及其演化过程指示了该区域存在“渗出”铀成矿作用。

川东南地区寒武系洗象池组碳、氧同位素特征及其意义——以贵州吼滩剖面为例

川东南地区寒武系洗象池组碳酸盐岩普遍发生白云石化,且缺乏生物化石,长期以来在地层对比与划分方面未形成统一认识。本研究在野外剖面和岩石学特征观察分析的基础上,对川东南地区中—上寒武统洗象池组41个碳酸盐岩样品进行了碳、氧同位素分析。结果显示,研究区洗象池组以泥晶—细粉晶白云岩为主,含少量残余砂屑白云岩、粗粉—细晶白云岩;样品的δ18 O值分布在-11.05‰~-8.29‰范围,平均为-9.67‰,δ13 C值介于-2.29‰~1.36‰之间,平均为-0.73‰,且δ18 O值和δ13 C值无明显正相关性,基本保留了同期海水的原生碳、氧同位素组成。分析表明,中—晚寒武世洗象池期川东南地区整体处于海相环境,其中中—晚期盐度相对早期盐度整体略微升高,海水温度分布在15.2℃~27.5℃,属于温暖或炎热的亚热带气候。SPICE(steptoean positive carbon isotope excursion)事件在吼滩剖面有很好的可对比性,可与全球其他地区进行对比,反映一次全球范围的海退事件。此外,通过对比川东南地区吼滩剖面与太和1井和渝东北地区利1井的碳同位素特征,认为渝东北地区盐度相对川东南地区较高,洗象池期盐盆地由川东南向渝东北演化,对于寻找盐类矿床和油气地质具有重要意义。

松辽盆地开鲁坳陷上白垩统姚家组与青山口组地层发育特征及铀成矿条件

松辽盆地开鲁坳陷找铀目标层主要为上白垩统姚家组和青山口组,二者同为红杂色建造,在区域上不易识别,层序格架不明,制约了找矿成果的扩大。文章通过岩性组合、地震界面追踪、测井相识别、生物化石组合、地球化学及重矿物分析指标等方法,初步识别出姚家组与青山口组的地层划分标志。结果显示:青山口组顶部以紫红色泥岩为主,下部为紫红色、灰色细砂岩、泥质中-粗砂岩夹薄层紫红色泥岩,地震相上表现为反射波连续性差、振幅小或中等、微弱的特征,测井曲线呈钟型、指型、箱型,风化指数(CIA)平均为57.16,重矿物以钛铁矿+石榴子石+重晶石+锆石为主;姚家组可分为上下两段,下段以褐红、砖红、灰色细砂岩、中砂岩、砂质砾岩为主,上段由一套灰绿、紫红色泥岩和灰白色粉砂岩、细砂岩、中砂岩组成,地震相上表现为反射波连续、振幅高或较高,底部中低振幅、中连续的反射同相轴等特征,测井曲线呈箱型、钟型,少量指型,风化指数(CIA)平均为65.22,底部风化指数(CIA)表现为突变增高,重矿物以锆石+石榴子石+白钛矿+锐钛矿+钛铁矿的组合为主。在此基础上,对姚家组与青山口组的铀成矿条件进行分析对比,研究认为,两者铀源主要来自松辽盆地南缘中、新生代火山岩和海西期、燕山期花岗岩,均具备充足铀源;青山口-姚家期均发育南西向北东展布河道,从上游至下游形成了冲积扇-辫状河-曲流河-三角洲-湖泊的典型沉积环境;青山口组及姚家组含矿灰色砂体中含有丰富的有机质、炭化植物碎屑、黄铁矿等还原剂,统计其有机碳含量为0.11%~0.56%,显示均具有较好的还原性;姚家组氧化带主要呈面状展布,余粮堡—钱家店及架玛吐—保康等地段成矿潜力巨大;青山口组氧化带呈环带状展布,奈曼、通辽—钱家店等地段成矿潜力较大。