贵州狮溪铝土岩型锂资源的发现及意义     

邓旭升  余文超  杜远生  杜威  熊兴国  曾禹人  龙建喜  张晗彬  符宏斌  何犇  卢树藩  罗香建 《地质论评》2022,68(5):2022102001-2022102001

狮溪锂资源位于贵州省桐梓县狮溪向斜东翼,是首次在黔北务（川）、正（安）、道（真）地区之外的下二叠统大竹园组中发现锂元素的异常富集。狮溪锂富集层位于大竹园组中—上部,具有厚度和品位均较为稳定的特征,含锂岩石类型为致密状和碎屑状铝土岩,主要矿物为伊利石（水白云母）。综合矿物学、岩石学及地球化学特征分析认为,该区域Li的富集与风化淋滤作用密切相关,受古气候、古地貌、地下水位等多因素控制。通过统计黔北地区和狮溪地区含铝岩系数据发现,Li含量与Al2O3、Al/Si值呈规律性变化,Li富集程度与大竹园组的岩性相关,大致可分为Li一般富集区（含矿岩石为泥岩或铝土质泥岩、较高品位铝土矿）和Li高度富集区（含矿岩石为铝土岩和低品位铝土矿）。本文通过狮溪锂资源的发现及综合分析认为,在黔北务（川）、正（安）、道（真）地区外围的近岸平原环境,特别是地势低洼处的致密状和碎屑状铝土岩中,具有发现较高品位铝土岩型锂资源的巨大潜力。  相似文献   

粤港澳大湾区水资源现状及其与社会经济协同演化趋势——与国际湾区对比研究          下载免费PDF全文

吴盼  赵信文  顾涛  江拓  王旭升  冯雨晴 《中国地质》2021,48(5):1357-1367

粤港澳大湾区（以下简称大湾区）水资源现状及其演化规律关系到该区社会经济的高质量发展。本文对大湾区"9市+2区"近10年的社会经济与水资源现状及其协同演化规律进行分析研究。结果显示：目前大湾区供水主要依赖地表水，水资源的分布与区域经济发展不协调，作为区域发展核心引擎的香港、澳门、深圳（极度缺水）以及广州（重度缺水）人均水资源量过低。广州、佛山、中山、东莞（>80%）以及深圳（>40%）水资源开发利用程度高，水资源供需压力大。通过归因分析得到大湾区的水资源利用现状与社会经济的协同规律：产业结构影响用水结构以及水资源开发利用程度，控制用水效率。区域内产业结构与发展趋势，及其与世界湾区的对比分析验证了产业结构理论中的"配第-克拉克定理"。随着大湾区经济持续的发展与产业结构优化，大湾区用水效率将提高，人均用水量会逐步降低。同时城市公共用水、生活用水需求量将持续上升，需确保大湾区供水设施，供水量及供水安全满足未来社会经济发展需求。  相似文献   

长江三峡坝区河谷深槽的地貌特征及其成因   总被引：10，自引：0，他引：10  

杨达源  李徐生  柯贤坤  周旅复  陈德基  杨天民  薛果夫 《地理学报》2002,57(5):547-552

通过实地观察，分析三峡工程坝区河谷深槽的地貌特征，并在此基础上，对三峡深槽的成因及其发育年代进行探讨，结果表明：（1）三峡坝区河谷深槽是在三峡地区构造抬升过程中，水流顺构造裂隙强裂侵蚀下切而形成的；对深槽堆积物中朽木进行的14C测年表明，三峡深槽的深切侵蚀大约发生在30－40ka BP;(2)三峡深槽的向下深切主要是急流（特别是漩流）携带岩砾对槽底进行研磨，掏蚀作用形成的；三峡坝区坝上深槽中的岩礁和左壁以及坝下深槽的右壁还受到急流携带岩砾的撞击、冲蚀、磨蚀和下沉流的垂向磨蚀作用；坝下深槽的左壁则是发育了深槽之后，由槽壁岩石的减压张裂及其水下的坍塌而拓展形成的；（3）深槽的平面延伸受到纵向裂隙构造的控制，最容易发生强烈深切的位置，则受到横向裂隙与纵向裂隙的受切部位控制；深槽中的深潭向下深切所能达到的深度，主要与局部水势的变化及床底岩石抗蚀强度的差异有关，其深度不受海面高度的限制。  相似文献   

温度对光棘球海胆不同发育阶段的影响   总被引：5，自引：0，他引：5       下载免费PDF全文

高绪生  孙勉英  胡庆明  李国友 《海洋与湖沼》1993,24(6):634-640

于１９８８－１９９０年进行水温（０－３０℃）对光棘球海胆不同发育阶段的影响的试验。结果表明，水温对光棘球海胆各发育阶段的生长等均有显著影响，并且，不同发育阶段对水温的要求不同。其中，低于５℃或者高于２６℃时，受精卵不发育；低于１５℃或者高于２４℃时，浮游幼体发育不正常；低于０℃或者高至３０℃时，幼海胆难以生存，生长适温在１６－２２℃；成海胆，０℃时活力显著减弱但短期内无死亡，３０℃则大量死亡，生长  相似文献   

Geomorphologic characteristics and origin of the valley bottom troughs at the site of Three Gorges Dam     

LI Xusheng  YANG Dayuan  KE Xiankun  ZHOU Lufu  CHEN Deji  YANG Tianmin  XUE Guofu 《地理学报》2003,13(4):507-512

This paper describes valley bottom troughs of the Changjiang River and infers the geomorphologic development of troughs. Based on the morphology of the troughs, the following conclusions are drawn. (1) The deep troughs on the Three Gorges valley bottom are formed by river downcutting along the structural zones on the background of regional tectonic uplift at about 40-30 ka BP. (2) When river downcutting occurred in the river bed of Changjiang, the jets current (particularly eddy current) with a large number of pebbles ground and eroded the valley bottom, resulting in trough formation and deepening. Meanwhile, water currents with gravels and pebbles eroded the bank and the left wall of No.76 trough as well as the right wall of No.77 trough by striking, scouring, horizontal and vertical grinding. (3) The depth of the trough is mainly determined by the intensity of the water current and the consistency of bedrock against erosion, and is not controlled by the altitude of the sea level as the base level of erosion.  相似文献   

Variation of Electromagnetic Tornogram Before and After Earthquakes     

Sun Cichang  Wang Xusheng  Liu Qingfang  Tao Yulu  Yu Ping  and Feng RuiInstitute of Geophysics  SSB  Beijing  China Department of Geophysics  Peking University  Beijing  China Seismnlogical Bureau of Hunan Province  Changsha  China Center for Seismological Data  Information  SSB  Beijing  China 《中国地震研究》1998,(2)

Cross-well electromagnetic tomography has been used to monitor the changes of the abso rption coefficient of electromagnetic waves before and after earthquakes for 5 years at Dahuichang fault since 1992.It has been found that 3 months before the occurrence of moderately strong earthquakes(ML≥4.0,△<210 km),several special changes in tomogram appeared as follows:The mean-value of the absorption coefficient dropped about 10% compared with the annually decreasing tendency; the mean difference of pixels suddenly decreased or increased in different directions; and the entropy of the paragenic matrix in a tomogram decreased and the number of low absorption pixels increased.It is inferred that such changes in electromagnetic tomograms are attributed to the variation of micro-cracks and porosity in rocks.Electromagnetic tomography can be studied as a new technique to detect earthquake precursors.  相似文献   

河流纵剖面陡峭指数对庐山构造抬升的指示     

王乃瑞  韩志勇  李徐生  陈刚  王先彦  鹿化煜 《地理学报》2015,70(9):1516-1525

庐山是位于江南造山带北缘的断块山,其抬升过程对于认识本区的构造演化至关重要。利用河流纵剖面的形态参数可以定量估算相对的构造抬升速率。基于5 m分辨率的DEM提取了庐山9条主要河流的纵剖面,依据坡度—面积图确定了裂点类型,结合地质图判别出裂点成因,并利用河流水力侵蚀模型计算了稳定态河段的陡峭指数以及凹曲度。结果显示,庐山的河流基本呈过渡态,以发育数量不等的裂点为标志;垂阶型裂点的形成主要与岩石强度不均一有关,而坡断型裂点是侵蚀基准面下降产生的。坡断型裂点以下的基岩河段具有较大的陡峭指数,表明庐山经历了从早期低抬升速率到晚期高抬升速率的转变。庐山受快速抬升影响的河段,陡峭指数具有南高北低的特点,主要是由于庐山整体抬升过程中南部、北部的抬升速率存在一定差异,亦可能是岩性不同造成的。  相似文献   

长江三峡深槽沉积的研究   总被引：4，自引：4，他引：0  

杨达源  李徐生  任黎秀  张建新  葛兆帅  王爱军  陈可锋 《第四纪研究》2004,24(5):501-505

文章研究长江三峡两个基岩深槽沉积岩砾的岩性组成与粒度特征,深槽底部的砾石成分以深槽基岩崩落蚀余物质为主,深槽的中上部则以长江底流搬运沉积物为主。¹⁴C测年数据显示,深槽的发育在3.5万年以前,以侵蚀深切为主,没有留下蚀余堆积;3.5万年以后,仍以侵蚀为主,但已有蚀余为主的岩块堆积;大约2.4万年以来,逐渐有缓慢的冲积砾石堆积;至葛洲坝建成以后,该地发育了比较稳定的冲积砾石层和砂层。看来大约35kaB.P.前后,该地水动力强度发生过重大变化,与施雅风等关于3～4万年前长江上游多雨期研究成果相吻合。  相似文献   

Sedimentary Facies and Distribution of Reservoir Rocks from the Feixianguan Formation in the Daxian-Xuanhan Region, NE Sichuan   总被引：1，自引：0，他引：1  

MA Yongsheng MOU Chuanlong GUO Xusheng YU Qian TAN Qinyin 《《地质学报》英文版》2006,80(1):137-151

The Lower Triassic Feixianguan Formation in the Daxian-Xuanhan region, northeastern Sicbuan is interpreted to be a carbonate platform intermediate between the West Hubei-East Cbongqing marine basin and Guangyuan-Wangcang marine basin. Outcrops, well logs and seismic data have disclosed that three sedimentary facies can be identified for the formation： open platform, platform exposed shoal and restricted platform facies. During the early stage of deposition of the Feixianguan Formation, there existed a sedimentary framework all the same as the Late Permian one： open platform in the west, and platform exposed shoal, restricted platform and open platform eastwards. The gradual increase of the shoal area permitted eastward migration of the shoal facies. During the deposition of the third member of the Feixianguan Formation, the study area was invaded by temporary transgressions. Till the deposition of the fourth member of the formation, the study area was prevailed over the unified restricted platform deposits, as indicated by the sedimentary model for the typical carbonate platform shoal deposits. The reservoir rocks in the Feixianguan Formation consist mostly of solution opening dolostone, and the rock types are assembled by oolitic dolostone, residual oolitic dolostone and sucrosic residual oolitic medium- to coarse-grained dolostone. The deep and shallow dual laterologs show relatively high resistivity, clear amplitude differences and time difference saltation of acoustic waves in some intervals. The seismic responses are indicated by low-frequency and highly variable amplitudes and chaotic reflection configurations. The reservoir rocks are characterized by high porosity-high permeability and medium porosity-medium permeability, showing a marked correlation between porosity and permeability. Solution openings are extremely developed in the reservoir rocks, including cast pores, intergranular solution openings, intercrystal pores, intercrystal solution openings, solution openings （caves） and minute fissures. Macropores and coarse pore throats are common. The reservoir rocks are apparently controlled by sedimentary facies in distribution patterns. Vertically, they occur dominantly in the second and first members of the Feixianguan Formation, and laterally in the platform exposed shoals and restricted platforms, where good natural gas potential is expected.  相似文献   

安徽宣城地区的“黄土”和旧石器文化   总被引：5，自引：1，他引：4  

杨达源  李徐生  鹿化煜  韩辉友  任黎秀  房迎三 《地质力学学报》1997,3(4):85-89

安徽省宣城地区发现几处风尘堆积剖面,它们的共同特征是普遍埋藏着旧石器时代的石制品。向阳陈山剖面(30°52'32″N,118°51'58″E)背依群岗,面向水阳江,剖面高约10m,大约是817kaBP以来形成的。全剖面连续采样的粒度分析与磁化率测量成果表明,该剖面除底部河漫滩相沉积-古土壤层外,还有8个"风尘堆积-古土壤层"旋回,风尘堆积的沉积环境与北方黄土的沉积环境相近。从剖面底部到近顶部,分散出土的旧石器时代石制品制作比较简单,进步缓慢,以尖状砍砸器为特色,与秦岭-淮河一线以北的旧石器时代石制品组合特征有明显的差别。   相似文献