大兴安岭北部砂宝斯蚀变砂岩型金矿地质特征

砂宝斯金矿为我国最近在黑龙江省漠河县发现的一大型蚀变砂岩型金矿床 (平均品位 4 .0 2× 10 -6)。矿体仅赋存于侏罗系二十二站组砂岩中 ,其下伏地层并不含矿。矿体分缓倾顺层矿体和陡倾穿层矿体 ,分别受 NS向缓倾断裂和陡倾断裂构造控制。矿石类型有蚀变砂岩型和构造破碎蚀变砂岩型 ,为少硫化物型矿石 ,其中金主要为微细粒金。稳定同位素及流体包裹体资料表明成矿流体是以天水为主的中低温热液。     

海塔盆地优质储层发育特征及控制因素分析

凝灰质砂岩是海塔盆地主要油气储集岩层,凝灰质含量随地层变老而增多,储层物性非均质性强,大量薄片等储层微观分析结果表明,凝灰质砂岩成分和结构成熟度较低,储层储集空间主要为溶蚀成因的次生孔隙,且次生孔隙比例随地层变老而增加.本文提出孔隙成因法,并根据该方法确定凝灰质砂岩优质储层物性下限的孔隙度为10％,渗透率为0.1×10...     

松辽盆地东北缘白垩系砂岩型铀矿成矿条件与找矿方向

通过松辽盆地东北缘蚀源区铀源条件、中生代构造演化、白垩系沉积建造研究,结合石油部门地震连井剖面等资料,综合分析了松辽盆地东北部砂岩型铀矿的成矿条件研究,认为盆缘的富铀花岗岩体提供了丰富的铀源,中生代后期反转构造形成的剥蚀天窗为含铀含氧水的渗入渗出提供了通道.研究结果显示,松辽盆地东北部绥棱地区为最有利的砂岩型铀矿找矿部位,主要找矿目标层为上白垩统泉头组兼顾浅部姚家组,找矿类型为层间氧化带型.     

Final Closure Time of the Paleo‐Asian Ocean: Implication from the Provenance Transformation from the Yangjiagou Formation to Lujiatun Formation in the Jiutai Area,NE China

The Jiutai area is tectonically situated at the eastern segment of the Central Asian Orogenic Belt(CAOB) and is close to the North China Craton(NCC) to the south, serving as an ideal place to investigations of the closure of the PaleoAsian Ocean(PAO). Sandstone samples collected from the Yangjiagou Formation and the Lujiatun Formation in this area have been studied in detail in terms of petrology, geochronology and geochemistry. The maximum depositional time of the Yangjiagou and Lujiatun formations has been constrained to early Middle Triassic(ca. 245 Ma) and middle Late Triassic(ca. 219 Ma), respectively. The Yangjiagou Formation, with a major provenance of dissected island arcs, is dominantly composed of Phanerozoic sediments from Northeastern China(NE China) massifs. The Lujiatun Formation, with major sediments from active continental margins, has a relatively larger proportion of Precambrian sediments, in which the ～1.85 Ga and ～2.5 Ga sediments are typical of the crystalline basements of the NCC and NE China massifs, which were uplifted and eroded during the closure of the PAO. Besides, both formations show the enrichment in LREEs and the depletion in HREEs, the common Eu negative anomalies, and trace element contents similar to that of the upper continental crust. Based on the provenance analysis of these two formations, the final closure time of the PAO in this area is constrained as from the early Middle Triassic(ca. 245 Ma) to the middle Late Triassic(ca. 219 Ma).     

安山岩中黄铜矿矿石分析和制硫酸铜工艺的研究

安山岩中的黄铜矿是庐江中生代陆相火山热液型铜矿床的原生矿，矿石中主要伴生黄铁矿及少量斑铜矿、赤铁矿和褐铁矿。物相分析结果，黄铜矿的粒度很细，只有细磨才能单体解离；它在矿石中分布极不均匀，且与脉石矿物接触疏松，适于粗磨抛尾。物性分析结果，黄铜矿在４００～５３０℃、斑铜矿在４５０～６００℃、黄铁矿在５００～６８０℃氧化分解。实验研究表明，矿石经磨碎磁选，大部分的粗粒级的铁矿物能够回收；粗磨抛尾可获得铜、硫的粗精矿；然后再经硫酸化焙烧、酸浸、过滤、提纯、浓缩结晶可制得工业级硫酸铜。浸渣做炼铁原料，黄钾铁矾做Ｆｅ２Ｏ３颜料，有时还可回收金、银。     

鄂尔多斯盆地上古生界两大气田不同石英砂岩储层 特征对比研究

通过对鄂尔多斯盆地上古生界榆林气田和苏里格气田石英砂岩储层特征的对比,指出榆林气田山2段石英砂岩储层属于相对低孔高渗型储层,苏里格气田盒8段石英砂岩储层属于相对高孔低渗型储层;通过分析两类石英砂岩的物源、沉积条件和成岩作用等因素,认为沉积期海水改造及后期成岩作用形成了榆林气田山2段储层的低孔高渗,而沉积时的高杂基含量与后期成岩共同作用形成了苏里格气田盒8段储层的高孔低渗。     

Carbon isotope composition of the Lower Triassic marine carbonates, Lower Yangtze Region, South China

The Early Triassic is a critical period in earth his- tory. A series of events such as volcano eruptions[1,2], sea-level fluctuations, changes in environmental con- ditions[3], mass extinctions[4,5] as well as global negative carbon isotope excursions[6-9] have been discovered in the uppermost Permian or across the Permian-Triassic boundary. Large scale sea-level rise[10-12], restoration of environment conditions, re- covery of ecosystem[13], including gradual carbon iso- tope rise[14] occur…     

用碎屑锆石SHRIMP年代学方法恢复松辽盆地南部前中生代基底的源区特征

松辽盆地东南隆起区基底广泛发育副变质岩,3件样品的SHRIMP锆石U-Pb年龄范围为406~2208Ma,反映了松辽盆地基底源区的复杂性。根据目前有关年代学研究成果,推断1100~2200Ma碎屑锆石可能来源于华北克拉通,而样品中的520Ma的碎屑锆石则可能来源于佳木斯地块。另外,样品的岩石学特征和临近大黑山条垒下二台群具有一定的可比性,推测文中样品可能是大黑山条垒在盆地内的延伸。     

松辽盆地地浸砂岩型铀矿勘查及其找矿方向

20世纪90年代开始,在松辽盆地开展了地浸砂岩型铀矿区域评价工作.盆地的西南部投入数万米钻探工作量开展以第三系和上白垩统嫩江组、姚家组为目的层的找矿工作,取得了较大突破,发现并提交了我国第一个板状砂岩型铀矿床,所建立的双混合叠造铀成矿模式丰富了地浸砂岩型铀成矿理论.在此基础上总结出白垩系砂岩型铀成矿控矿因素和找矿标志.盆地东部构造反转有利于形成砂岩型铀矿床.第三系以潜水氧化为主,还原物质缺乏,而且新构造运动对其改造微弱,总的成矿条件不理想,不宜作为主攻目的层.盆地坳陷阶段沉积的泉头组、青山口组、姚家组为主要找矿目的层,找矿重点在盆地东南部通辽-双辽-德惠地区.下一步科研工作重点为:完善QJD砂岩型铀矿模式、盆地油气与铀成矿关系、白垩纪古水文地质条件的研究.     

Longitudinal variations of phytoplankton compositions in lake-to-river systems

To test the hypothesis of longitudinal variations in phytoplankton compositions from a eutrophic lake to its river downstream and determine the length of the transition zone, we applied functional groups as well as taxonomical methods to this coupled aquatic system, which is composed of the Dianchi Lake upstream and the Tanglang River downstream, by sampling at 9 stations during Microcystis blooms in the Dianchi Lake in 2013. The longitudinal variations in phytoplankton compositions from lacustrine species to fluvial species were reflected by: (1) the shift from Microcystis to Chlorococcales green algae and centric diatoms; (2) the shift from the dominance of codon M to the coexistence of a variety of coda without one outstanding codon; and (3) except for codon M, the shift from lacustrine coda (H1, L_O, T) towards coda that are adapted to both lacustrine and fluvial circumstances (MP, X1, X2). The prominent difference of phytoplankton compositions between the Dianchi Lake and the lower reaches of the Tanglang River revealed that there was a transition zone in between. The upper and middle reaches of the Tanglang River with a length of approximately 26.4 km were considered the transition zone because: (1) the dominant lentic codon M in the Dianchi Lake disappeared at the lower reaches of the river; (2) the amount of codon P that is sensitive to stratification rose at the beginning of the river; and (3) the codon T, which is well adapted to the persistently mixed layer or epilimnia of lakes, lost a large number of biomass at the upper and middle reaches of the Tanglang River. In this study, we found that the eutrophic lake had a significant influence on the river downstream. In addition, we found that functional groups were sensitive to the changes of external aquatic conditions and helpful in determining the length of the transition zone.