陆相红层型铜铅锌矿床与红层盆地热卤水成矿作用   总被引：1，自引：1，他引：0       下载免费PDF全文

杨兵 《中国地质》2018,45(3):441-455

新疆乌恰县乌拉根超大型铅锌矿是中国发现的首个产于陆相红层盆地中的红层型铅锌矿床,对其成矿作用及成因有多种不同认识,但都将其归入现有的一些矿床类型,如喷流沉积型、砂岩型等,却均不能反映其独特的成矿环境与成矿作用。为此,在广泛收集和研究全国陆相红层盆地及其矿产的地质资料基础上,通过区域地质构造背景、含矿建造、矿床特征、控矿因素、成矿物质来源、成矿流体等方面对比分析,认为乌拉根铅锌矿与中国大量产于陆相盆地内红色建造中的红层铜矿,在矿床特征、控矿条件、矿床成因等方面具有高度的一致性,均为陆相红层盆地热卤水作用的结果,是同一类型的矿床。红层型矿床是地洼区的特有矿产,是地球地质演化到地洼阶段才出现的新的矿床类型,陆相红层盆地热卤水作用是一个完全独立的成矿系统,因此将其作为一个单独的矿床类型——红层型矿床是合理的,既具有重要理论意义,也具有重要的实践意义,为铅锌矿找矿开辟了新的方向和领域。  相似文献   

辽宁凌源四合当地区九佛堂组珍稀化石层划分及意义     

高福亮  江洋  潘玉啟  王烜  吴子杰  樊硕  戴德宇 《地质与资源》2018,27(6):503-507

辽宁省凌源市四合当地区九佛堂组含有丰富的中生代热河生物群化石,尤其是珍稀化石.通过剖面测制、化石采集以及实地调查等手段,将九佛堂组划分为3个段,确定了化石层的分布及重要化石的产出层位,同时命名了3个化石层：一段的韩家沟层、二段的卅二道湾层、三段的四合当层,加深了辽西九佛堂组化石层的研究程度.  相似文献   

Geologic structure and correlation of the Berriasian-Lower Aptian productive beds of the Gydan Peninsula (Russian Arctic)     

S.V. Ershov  V.N. Bardachevskii  N.I. Shestakova 《Russian Geology and Geophysics》2018,59(11):1497-1507

We discuss the geologic structure of the Berriasian-Lower Aptian deposits of the Gydan Peninsula. Eight seismic sequences have been distinguished; most of them are associated with Lower Cretaceous regional clinoforms of West Siberia, their characteristics are given. A correlation of productive beds was based on the stratotype sections of the Yamal and Gydan Peninsulas as well as seismic and well data. A sequence stratigraphic model of the Berriasian-Lower Aptian complex is proposed.  相似文献   

A Rhaetian microvertebrate fauna from Stowey Quarry,Somerset, U.K.     

Iacopo Cavicchini  H. Cecilia Heyworth  Christopher J. Duffin  Claudia Hildebrandt  Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):144-158

Rhaetian bone beds have been described from many locations in south-west England, around Bristol. One site that has never been reported is Stowey Quarry, some 13?km south of Bristol. This quarry yielded Lias, and revealed thin Rhaetian units in the quarry floor, including two bone beds, the basal Rhaetian bone bed, and a second, higher bone bed, also within the Westbury Formation. The fossil fauna of both includes elements typical of Rhaetian bone beds elsewhere, but showing differences in faunal composition between the two. The basal bone bed yielded more specimens and more species, with three taxa (Sargodon tomicus, Rhomphaiodon minor and Hybodus cloacinus) exclusive to this bed and eleven identified in total. Severnichthys acuminatus accounts for more than 50% of the countable teeth from the basal bone bed, followed by Gyrolepis albertii with 20%, Lissodus minimus with 14% and Rhomphaiodon minor with 9%. The basal bone bed, as ever, is dominated by chondrichthyans, whereas the upper bone bed is dominated by osteichthyans, which form 90% of the non-dental remains. The only unique taxon is Dapedium, and Gyrolepis albertii is the most abundant species with 45% of countable teeth, followed by Severnichthys acuminatus with 38% and Duffinselache holwellensis with 11%. These faunal differences, and the equally good condition of specimens between both samples confirms that the upper bone bed is independent of the basal bone bed, and is not a reworked subsample.  相似文献   

塔里木盆地和田河气田周缘寒武系盐下白云岩油气勘探潜力分析          下载免费PDF全文

曾昌民 李 勇范秋海  冯晓军张 亮 陈 才朱礼春  陈延贵李向云 《地质科学》2018,(4):1413-1439

塔里木盆地塔西南地区和田河气田周缘寒武系中统发育厚层膏盐岩,其下白云岩溶蚀裂缝-孔洞型储层发育条件好。多个层系具备烃源岩发育条件,除寒武系下统玉尔吐斯组外,震旦系、南华系也是可能的重要生油层系,油气资源丰富。盐下发育多个规模较大的构造圈闭,且由于膏盐岩层的滑脱作用,断裂很难断穿盐层,后期保存条件好。因此,寒武系中统膏盐岩与下伏白云岩组成本区重要的储盖组合,勘探领域具有非常好的前景。  相似文献   

湘江下游河床沉积物元素地球化学背景值估算     

赵亚方  彭渤  方小红  邬思成  刘静  陈丹婷  戴亚南 《地质论评》2021,67(2):504-521

本研究对湘江下游河床沉积物进行了元素地球化学分析,在认识沉积物元素地球化学特征、甄别人为源与自然源重金属的基础上,估算了沉积物的元素地球化学背景值。结果表明:SiO2、TiO2、Al2O3、Fe2O3、K2O等主量元素及V、Co、Cr、Ba、Sc、U、Sr、Ga、Ge、Rb、Nb、Y、REE等微量元素在沉积物中含量变化相对稳定(Cv<0.2),分布相对均匀,且富集不明显(EF<2.0,Sr明显亏损)。而MnO、MgO、CaO、Na2O、P2O5等主量元素,及Cd、Mn、Cu、Pb、Zn等重金属在沉积物中含量变化大(Cv>0.25),分布极不均匀,且沉积物中重金属明显富集(EF>2.0)。主成分及Pearson线性相关性分析显示,沉积物中不明显富集的微量元素主要赋存于难溶硅酸盐矿物相中,为自然源元素。而沉积物中显著富集的重金属主要赋存于铁—锰氧化物等矿物相中,为有人为源叠加的元素。故针对不同来源特征的元素用不同的方法进行了背景值计算,求得沉积物中47个元素的背景值。再利用元素比值等方法对所得背景值进行检验。结果表明,本文得到的湘江沉积物元素背景值合理,可用作流域沉积物重金属污染评价参考。  相似文献   

渤南洼陷沙四下亚段沉积时期古气候演化     

徐琦松  王永诗  马立驰  孟涛  毕俊凤  王天宇 《地质论评》2021,67(Z1):67z1127-67z1128

正全球于古近纪发育PETM、ETM2、EECO、和MECO多个短期热气候事件(雷华蕊等,2018)。受热气候事件影响,渤南洼陷沙四下亚段沉积时期红层沉积发育并记录着热气候事件控制下古气候演化过程。立足于渤南洼陷沙四下亚段红层,恢复古气候演化过程,一方面可以点带面,揭示全球古近纪气候演化;另一方面为研究极端气候条件对湖盆沉积体系的控制作用奠定基础。  相似文献   

六种成膜封堵剂的室内实验优选与评价          下载免费PDF全文

王建伟 《探矿工程》2021,48(3):73-77

为更好地服务深部钻探工程,准确了解冲洗液封堵性能,对6种成膜封堵剂开展了砂床实验、API静失水量实验、流变性能实验及抗温实验等室内实验进行优选与评价。实验结果表明,2号和4号成膜封堵剂在6种成膜封堵剂中封堵性能最好,它们在基浆中的最优加量均为2%,100 ℃温度条件下加入这2种封堵剂的冲洗液具有较好的抗温性能;冲洗液中膨润土含量和处理剂是影响冲洗液封堵性能的2个重要因素：膨润土含量越高,冲洗液封堵性能越好,加入聚合物、降滤失剂等处理剂可以提高冲洗液的封堵性能。砂床实验是评价冲洗液封堵性能好坏的重要依据。  相似文献   

Bed material texture in low order streams on the Queen Charlotte Islands,British Columbia     

Stephen Rice  Michael Church 《地球表面变化过程与地形》1996,21(1):1-18

Low order channels comprise a large proportion of the links of every drainage basin, and are often at the centre of land management concerns. They exhibit hydrological and geomorphological characteristics atypical of higher order links. This paper examines the nature and causes of variations in the bed material texture of two streams on the Queen Charlotte Islands, British Columbia. The extant, functional exponential model is found to be inadequate for explaining observed changes in grain size parameters with distance downstream. Recurrent disruption of sediment transport by large organic debris jams, and the sporadic contamination of the fluvial sediment population by colluvial inputs, preclude the development of longitudinal structure. Rather, grain size varies erratically over short distances. A stochastic model best describes the observed variations, and should be adopted as an alternative to the exponential model in low order links. Characteristic variances are controlled by the degree of hillslope-channel coupling, and the extent and characteristics of non-alluvial storage mechanisms.  相似文献   

地震资料预测薄层厚度方法研究与应用   总被引：25，自引：15，他引：10       下载免费PDF全文

柏冠军  吴汉宁  赵希刚  王靖华 《地球物理学进展》2006,21(2):554-558

薄层厚度预测一直是公认的难题之一,其难度就在于如何准确地识别和提取薄层的地震属性.常规方法是利用时间域或频率域地震属性与薄层厚度的线性关系计算.但是理论与实际资料表明,不同的薄层和地层组合对地震波的动力学的信息影响很大,各种参数与薄层厚度成非线性关系,使用单一的信息不可能准确预测薄层厚度.本文利用三种线性预测原理（模型）,经数学变换为属性参数,采用非线性BP网络预测薄层厚度,取得了令人满意的效果.  相似文献