Tracing of natural gas migration by light hydrocarbons:A case study of the Dongsheng gas field in the Ordos Basin,NW China

Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane,the indication of geochemical characteristics of light hydrocarbons on the migration features,dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed,and the effect of migration on specific light hydrocarbon indexes is further discussed.The study indicates that,natural gas from the Lower Shihezi Formation(Pix)in the Dongsheng gas field displays higher iso-C5-7contents than n-C5-7contents,and the C6-7light hydrocarbons are composed of paraffins with extremely low aromatic contents(<0.4%),whereas the C7light hydrocarbons are dominated by methylcyclohexane,suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution.The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging,and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation.Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C7 light hydrocarbons and the toluene/n-heptane ratio,as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values.The dissolution causes the increase of isoheptane values of the light hydrocarbons,whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C5-7contents compared to the iso-C5-7contents.

Petroleum geochemistry and origin of shallow-buried saline lacustrine oils in the slope zone of the Mahu sag, Junggar Basin, NW China

Recently, significant oil discoveries have been made in the shallower pay zones of the Jurassic Badaowan Formation (J_(1)b) in the Mahu Sag, Junggar Basin, Northwest China. However, little work has been done on the geochemical characteristics and origins of the oil in the J_(1)b reservoir. This study analyzes 44 oil and 14 source rock samples from the area in order to reveal their organic geochemical characteristics and the origins of the oils. The J_(1)b oils are characterized by a low Pr/Ph ratio and high β-carotene and gammacerane indices, which indicate that they were mainly generated from source rocks deposited in a hypersaline environment. The oils are also extremely enhanced in C_(29) regular steranes, possibly derived from halophilic algae. Oil-source correlation shows that the oils were derived from the Lower Permian Fengcheng Formation (P_(1)f) source rocks, which were deposited in a strongly stratified and highly saline water column with a predominance of algal/bacterial input in the organic matter. The source rocks of the Middle Permian lower-Wuerhe Formation (P_(2)w), which were deposited in fresh to slightly saline water conditions with a greater input of terrigenous organic matter, make only a minor contribution to the J_(1)b oils. The reconstruction of the oil accumulation process shows that the J_(1)b oil reservoir may have been twice charged during Late Jurassic–Early Cretaceous and the Paleogene–Neogene, respectively. A large amount volume of hydrocarbons generated in the P_(1)f source rock and leaked from T_(1)b oil reservoirs migrated along faults connecting source beds and shallow-buried secondary faults into Jurassic traps, resulting in large-scale accumulations in J_(1)b. These results are crucial for understanding the petroleum system of the Mahu Sag and will provide valuable guidance for petroleum exploration in the shallower formations in the slope area of the sag.

The Original Organism Assemblages and Kerogen Carbon Isotopic Compositions of the Early Paleozoic Source Rocks in the Tarim Basin, China

Original organisms are the biological precursors of organic matter in source rocks. Original organisms in source rocks are informative for oil-source rock correlation and hydrocarbon potential evaluation, especially for source rocks which have high-over level of thermal maturity. Systematic identification of original organism assemblages of the Lower Paleozoic potential source rocks and detailed carbon isotopic composition of kerogen analyses were conducted for four outcrop sections in the Tarim basin. Results indicated that the original organism assemblages of the lower part of the Lower Cambrian were composed mainly of benthic algae, whereas those of the Upper Cambrian and the Ordovician were characterized by planktonic algae. Kerogen carbon isotopic data demonstrated that the δ13 Ckerogen values of source rocks dominated by benthic algae are lower than-34‰, whereas the δ13 Ckerogen values of source rocks dominated by planktonic algae are higher than-30‰ in general. We tentatively suggested that the carbon species those are utilized by algae and the carbon isotopic fractionation during photosynthesis are the major controls for the δ13 Ckerogen values in the Lower Paleozoic source rocks in the Tarim basin. Correlating the δ13 C values of oils exploited in the Tarim basin, the original organism assemblages, and δ13 Ckerogen values of source rocks, it implied that the Lower Paleozoic oils exploited in the Tarim basin should be sourced from the source rocks with original organism assemblages dominated by planktonic algae, and the hydrocarbon sourced from the Cambrian benthic algae should be of great exploration potential in future. Original organism assemblages in source rocks can provide important clues for oil-source rocks correlation, especially for the source rocks with high thermal maturity.

Organic geochemical and petrographic characteristics of the Cambrian-Ordovician organic-rich marine shales in Scandinavia

This work used organic geochemistry and organic petrology to study the depositional environment,organic matter characteristics,and thermal maturity of the Cambrian-Ordovician organic-rich marine shales in the Baltic Basin.The main macerals in Cambrian samples include alginite,bituminite and solid bitumen,while zooclastic macerals become the major proportion of organic matter in the Ordovician samples.As the maturity increase,solid bitumen becomes abundant and dispersed.Semifusinite-like maceral was observed only in Furongian of well DBH15/73,which probably indicates the local intrusion of Permo-Carboniferous dolerite dikes.The programmed pyrolysis results show that immature,early mature,and over-mature samples are developed.However,the data of high-uranium Furongian samples were greatly altered by igneous intrusives from local dikes.HIo calculation model is simulated based on pyrolysis data and fitted according to the least-square fitting method.The simulated fitting HIo:400mg HC/g TOC(369.5 mg HC/g TOC,430.5 mg HC/g TOC as 95%confidence bounds)is within the worldwide marine shale HI_(o)and indicates a marine anoxia and transgressive sea with shallow water column(organofacies B).

The Four Stages in the Origin of Rice Agriculture

In recent years,due to the widespread application of flotation,a large number of plant remains related to the origin of rice agriculture have been found in the middle and lower reaches of the Yangtze River.Through the study of these new findings,it has been discovered that the origin of rice agriculture was a long and gradual process lasting for thousands of years.This process can be divided into four stages:the stage of gestation took place around 10,000 years ago—human society was still in the hunting and gathering phase,but archaeological evidence of human-used or even cultivated Oryza plants from that time has been discovered;the early stage of transition took place around 9000–7000 years ago—archaeological evidence of rice farming from that time has been found,such as villages,domesticated rice,farming tools,etc.,but subsistence then was still mainly based on hunting and gathering,whereas rice farming and pig breeding,which fall into the agricultural production category,were only auxiliary production activities;the late stage of transition took place around 7000–5000 years ago,when the proportion of subsistence attained by hunting and gathering gradually declined while the proportion of rice farming increased day by day;and the stage of completion took place about 5000 years ago,when hunting and gathering was replaced by rice agriculture in the middle and lower reaches of the Yangtze River successively.

Geochemistry of cherts from the northern Jiangxi region,South China:Implication for paleoenvironment

The extensive bedded cherts deposited during the Ediacaran-Cambrian(E-C)transition period play a crucial role in understanding the geological evolution of this period,yet the origin of these cherts remains disputed.Here,we present new geochemical data for cherts of the Piyuancun(PYC)Formation deposited during the Late Ediacaran and the Hetang(HT)Formation deposited during the Early Cambrian in northern Jiangxi region,Lower Yangtze region,South China.The PYC cherts contain a small amount of monaxons sponge spicules and radiolarian fragments,while the HT cherts lack siliceous organism evidence.Major and trace element analysis,coupled with discriminant diagrams,indicate a possible shift in redox conditions of seawater during the E-C transition in the northern Jiangxi region.The shift suggests a change from weakly-moderately restricted euxinic conditions to strongly restricted euxinic conditions.Furthermore,the location of both cherts are distant from the source area of siliceous organisms.Fossil evidence,as well as the values of Fe/Ti and Fe/(Mn+Ti),Eu anomalies,Post-Archean Australian Shale(PAAS)normalized REE+Y patterns,and various discriminant diagrams,support the conclusion that the PYC and HT cherts originated primarily from direct seawater precipitation,with the PYC cherts exhibiting weak hydrothermal evidence.Upwelling contributes to the formation of HT cherts and organic matter(OM)accumulation.Ocean acidification,triggered by OM degradation and biodegradation processes during the E-C transition period,leads to the extensive silica precipitation and preservation.These results enhance our understanding of the geological processes during the E-C transition.

Technology demonstration of a novel poly-Si nanowire thin film transistor

A simple process flow method for the fabrication of poly-Si nanowire thin film transistors（NW-TFTs） without advanced lithographic tools is introduced in this paper.The cross section of the nanowire channel was manipulated to have a parallelogram shape by combining a two-step etching process and a spacer formation technique.The electrical and temperature characteristics of the developed NW-TFTs are measured in detail and compared with those of conventional planar TFTs（used as a control）.The as-demonstrated NW-TFT exhibits a small subthreshold swing（191 mV/dec）,a high ON/OFF ratio（8.5 × 10~7）,alow threshold voltage（1.12 V）,a decreased OFF-state current,and a low drain-induced-barrier lowering value（70.11 mV/V）.The effective trap densities both at the interface and grain boundaries are also significantly reduced in the NW-TFT.The results show that all improvements of the NW-TFT originate from the enhanced gate controllability of the multi-gate over the channel.

Using in situ REE analysis to study the origin and diagenesis of dolomite of Lower Paleozoic,Tarim Basin

In situ REE concentrations of various dolomites from Tarim Basin were obtained by LA-ICP-MS analysis,and the data were normalized to standard seawater(Seawater Normalized=SWN).Most of the samples have a ΣREE range of less than 20 ppm.All samples show similar REESWN distributions with heavy REE depletion,and positive Ce anomaly,which indicates that they have the same dolomitization fluids(seawater).According to the origin and diagenetic process of dolomite,two types of dolomite are determined and described as follows:1) syndepositional dolomite,with the highest REE concentrations(more than 20 ppm),the cores of which are more enriched in REE compared with their cortexes,indicating that they underwent the dolomitization of calcareous sediments by hypersaline and subsequent diagenesis decreased the REE content of the cortex because of the low REE concentration of the diagenetic fluids;2) diagenetic dolomite,which can be subdivided into four groups.(1) burial dolomite which has higher REE concentrations than limestone,but lower than syndepositional dolomite.This shows that pore fluids with high salinity dolomitized the pre-existing limestone;(2) void filling dolomite which has the similar REE patterns with the matrix dolomite.In addition,the Eu anomaly is not obvious,suggesting that the dolomitization fluids originated from the diagenetic fluids;(3) recrystallized dolomite,whose REE concentration was obviously decreased,indicating that the REE concentration was decreased during the recrystallization processes;and(4) hydrothermal altered void-filling dolomite,which has the lowest REE concentration,but obvious positive Eu anomaly,reflecting its hydrothermal activity related origin.Thus,the diverse REE signatures,which were recorded in different dolomites,retain the information of their formation conditions and subsequent diagenetic processes.In situ REE analysis of dolomite is an effective probe into the origin and diagenetic process of dolomite.

天然气运移轻烃地球化学示踪--以鄂尔多斯盆地东胜气田为例

基于天然气中轻烃化合物组成分析和区域性对比,结合组分和甲烷碳同位素组成特征,揭示轻烃地球化学特征对鄂尔多斯盆地东胜气田上古生界天然气运移和水溶及逸散等示踪作用,探讨运移作用对特定轻烃指标的关联效应。研究表明:①东胜气田二叠系下石盒子组天然气C5−7异构烷烃含量高于正构烷烃,C6−7轻烃组成呈链烷烃优势分布且芳香烃含量明显偏低(小于4.0%),C7轻烃主体呈甲基环己烷优势分布,整体表现出煤成气特征且受到了水溶等作用影响;②东胜气田天然气经历了自南向北的游离相运移,并在充注后发生不同程度的水溶作用,其中泊尔江海子断裂以北什股壕地区天然气在聚集后具有明显的散失;③长距离的游离相运移导致天然气C7轻烃中甲基环己烷相对含量和甲苯/正庚烷值降低、正庚烷/甲基环己烷值和庚烷值增大,水溶作用导致轻烃异庚烷值增大,天然气散失导致什股壕地区天然气中C5−7正构烷烃相对异构烷烃含量增加。

水稻驯化与中华文明的起源——中国地理教学中的思政教育

作为世界文化遗产,良渚文化确证了中华民族的5 000年文明史.这与水稻的起源密切有关.水稻起源的讨论始于19世纪,由瑞士植物学家阿方斯·德康多尔基于文献证据认为起源于中国和印度,历经不同国家学者的反复认证,起源于长江中下游已成基本共识.大致说来,水稻起源于10 000年前的长江中下游,后历经尝鲜、补充,直到5 000年前才正式成为当地食物供应的主体.大体上,10 000年前的上山遗址,表明了水稻的驯化和稻作农业的起源,仍然处在最初阶段.到了7 000~8 000年前的河姆渡文化时期,人类社会依然处于由采集狩猎向稻作农业社会的转变过程中,人类还没有进入到真正的稻作农业社会阶段.良渚文化时期,中国的长江下游地区已经进入到了稻作农业社会阶段,完成了从采集狩猎向稻作农业的转变过程.水稻和小麦为全球两大主粮.约10 000年前,小麦起源于两河流域,后扩散至埃及和印度河流域.在四大古文明中,唯有中华文明的生产基础是水稻,其余三个文明均是小麦.从西至东,古埃及文明、古两河文明、古印度文明以及中华文明(良渚文化),非常巧合的是它们均恰好位于北纬30°线上,体现出5 000年前古代文明出现的规律性.

针刺结合引火归元穴位贴敷治疗上实下虚型颈性眩晕临床观察

目的观察针刺结合引火归元穴位贴敷治疗上实下虚型颈性眩晕的临床效果。方法选取120例上实下虚型颈性眩晕患者,按随机数字表法分为针刺组、引火归元组、针刺+引火归元组与西药组并行相应治疗,每组30例。比较四组治疗前后颈性眩晕症状与功能评估量表评分、血清内皮型一氧化氮合酶(eNOS)及人降钙素基因相关肽(CGRP)水平变化,治疗结束后3个月进行回访比较复发率。结果治疗后,四组颈性眩晕症状与功能评估量表评分均较治疗前显著升高,且针刺+引火归元组升高幅度大于其余三组(P<0.05);四组血清eNOS、CGRP水平均较治疗前显著升高,且针刺+引火归元组升高幅度大于其余三组。治疗结束3个月后,针刺+引火归元组复发率为26.67%(8/30),低于其余三组。结论常规针刺、引火归元穴位贴敷、针刺结合引火归元穴位贴敷与口服甲磺酸倍他司汀片等方法对上实下虚型颈性眩晕患者均疗效确切,且针刺结合引火归元穴位贴敷效果最优、复发率最低,值得推广。

老锦雄应用温针背俞穴联合刺血疗法治疗围绝经期综合征上热下寒证经验

围绝经期综合征为妇科常见疾病,常兼具心理症状及躯体症状双重表现。老锦雄提出围绝经期综合征上热下寒证内在病理特点为元气亏虚、脏腑功能失和,核心病机为元气虚衰、相火妄动,通过温针灸背俞穴联合放血疗法以培补元气、引火归元,为治疗该病提供新思维、新方法。

Stretching characteristics and its dynamic significance of the northern continental margin of South China Sea

To investigate the thinning of the whole crust, and the contribution of the upper versus lower crust to the stretching since Cenozoic, we calculated the stretching factor of the northern margin of South China Sea with data such as whole crustal thickness, depth of Cenozoic sedimentary basement and the horizontal displacement of faults. An isometric line drawing on whole crustal stretching factor is then obtained. Along the seismic Line 1530 in Baiyun sag, we also calculated the stretching factors of the upper and lower crust. The results suggest that the whole crustal thickness decreases seaward while the whole crustal stretching factor increases from shelf to slope. The Moho upwells highest beneath where the crust is thinned most. The value of the whole crustal stretching factor ranges from 1.5 to 6. Two areas were thinned intensely: the center of Yinggehai Basin, and the Baiyun sag in the Pearl River Mouth Basin. The calculation of the upper and lower crustal stretching factors from DSP1530 in Baiyun sag shows that the original crust of Baiyun sag should be thinned before deformation. Its pre-Cenozoic evolution as well as tectonic position during Cenozoic might be responsible for that.

New Insight into Factors Controlling Organic Matter Distribution in Lower Cambrian Source Rocks: A Study from the Qiongzhusi Formation in South China

Sedimentary organic matter(OM) is a major reservoir of organic carbon in the global carbon cycle. Despite many studies, there still exist many debates on the mechanism of OM accumulation and preservation in marine sediments. We present a new field study of a Lower Cambrian shallow marine shelf sequence in the northern edge of the Yangtze Plate, China. Our results show that palynological OM and biogenic silica(Bio-Si) could be used alongside more conventional redox and paleo-productivity proxies to study the distribution of OM in marine sediments. The qualitative and quantitative study of palynological OM provides more detailed information on the nature of sedimentary organic carbon, which can be helpful in the assessment of primary productivity and OM preservation. In addition, the presence of Bio-Si stimulates the physical preservation of OM. Further analysis indicates that an increase in Bio-Si can promote OM preservation. This case-study provides insight into the intertwined factors controlling OM accumulation in the Early Cambrian.

New observations of the lobopod-like worm Facivermis from the Early Cambrian Chengjiang Lagerstatte

Facivermis yunnanicus (Hou & Chen, 1989), from the Early Cambrian Chengjiang Lager- st?tte, a worm-like fossil with 5 pairs of tentacles and a perceived shrunken end, has been regarded as related to polychaetes, later it has been variously interpreted as lobopods, Pentastoma and lopho- phorates. Newly discovered complete specimens by the ELI field team show that the taxon has, in addition to the 5 pairs of appendages, a pear-shaped trunk end bearing two or three circles of hooks. Accordingly, based on these important morphological characters, reconsideration of its affinities is provided and the taxonomy is remedied herein. Because the five pairs of appendages of Facivermis yunnanicus resemble the appendages of the fore-trunk of lobopod Mi- raluolishania (Liu & Shu, 2004), it seems that they are homologous structures. Therefore, the affinities of Facivermis are regarded here as being close to the lobopods, in addition, the lobe-like appendages of Facivermis are very crucial to exploring the origin of the appendages of lobopods and arthropods.

黄河下游河道泥沙不均衡调整及其对水沙条件的响应

黄河下游河床调整主要取决于来水来沙条件和河床边界条件,水沙和边界条件又受到人类活动的影响。黄河下游河床演变极其复杂,河床纵横向冲淤调整不均衡特征明显,不均衡冲淤可能形成排洪“瓶颈”河段,危害河道防洪安全。针对河道不均衡调整现象,从不同河段河槽冲淤量、河槽横断面变化、水文站3 000 m^(3)/s同流量水位变化等方面,分析了各河段不同时期河道不均衡调整特征及河槽恢复水平,揭示了排洪“瓶颈”河段形成、发展及消失与水沙条件的关系。目前夹河滩以上河段的河槽基本恢复到1969年或1960年以来最好水平,夹河滩至高村河段恢复到1989年水平,高村至利津河段恢复到1985年水平。研究成果可为黄河下游水沙调控提供理论支撑。

不同类型橡木桶陈酿干红葡萄酒中橡木源挥发性香气物质差异分析

开展不同烘烤度及产地的橡木桶陈酿干红葡萄酒的实验,采用液-液萃取结合气相色谱-质谱联用(LLE-GC-MS)法探究不同类型橡木桶桶储12个月及出桶后瓶储12个月期间的赤霞珠干红葡萄酒中27种橡木源香气物质的差异。结果表明,对于烘烤度而言,桶储12个月后,中度烘烤橡木桶陈酿葡萄酒中呋喃(3.53~21.37 mg/L)、酚醛(1.78~3.05 mg/L)和挥发性酚(321.47~568.03μg/L)含量较高。橡木内酯则在轻度烘烤橡木桶陈酿酒中较高(256.56~1284.49μg/L)。对于橡木产地差异而言,美国桶陈酿酒中顺式-橡木内酯、丁子香酚、愈创木酚和反式-异丁香酚含量更高,法国桶和斯洛伐克桶陈酿酒中反式-橡木内酯含量更高。出桶后继续瓶储期间,除糠醛、5-甲基糠醛和香草醛呈下降趋势,多数橡木源香气物质含量无明显变化。因此,美国桶陈酿能给葡萄酒带来更多的橡木香气,不同橡木桶对葡萄酒中橡木源香气物质的影响可以延续到瓶储阶段,其中烘烤度的影响比产地更持久。

松辽盆地西南部上白垩统姚下段红色砂体特征、成因及找矿意义

松辽盆地主力产铀层位——姚下段红色砂体的成因是制约砂岩型铀矿找矿思路的关键问题之一。文章通过开展盆地西南部姚下段红色砂岩的岩石学、矿物学及时空特征的系统研究,明确了松辽盆地西南部姚下段的红色砂体宏微观特征。在此基础上,结合姚下段沉积期古气候、伴生红色泥岩、古河道、古水深等多因素耦合分析,认为姚下段红色砂体呈面状展布、砂体厚度中心严格受古河道控制、岩石孔隙间发育强烈赤铁矿化等一系列宏微观特征是姚下段沉积期受极热气候事件影响的炎热干旱古气候背景中的震荡变热旋回的陆上河流相沉积的地质记录,提出松辽盆地西南部姚下段红色砂体主体以极热古气候控制下的原生河流相沉积成因为主。在此基础上提出盆地西南部钱家店断陷、龙湾筒断陷等深部富铀建造之上红杂色建造中原色红色砂岩断裂附近的灰色砂岩透镜体,姚下段红色砂岩中夹的薄层灰色泥岩附近的灰色砂岩集中区,均是有利的渗出成矿目标地质体。该研究明确了盆地西南部主力产铀层位红杂色建造的原生性,指出姚下段具备渗出成矿的先决条件,进而为区内利用渗出找矿新思路开展找矿工作指明了方向。

深圳原关外地区儿童下呼吸道感染病原菌特征及耐药性分析

目的探究深圳原关外地区儿童下呼吸道感染病原菌特征及耐药性。方法选取2021年1月-2022年12月深圳原关外地区儿童下呼吸道感染患儿为研究对象,对其下呼吸道分泌物标本进行细菌培养和非典病原体、病毒检测,选择纸片扩散法监测细菌药敏性。结果分离出来的病原菌共计1298株,其中,革兰阳性菌377株,占比29.04%,主要包括金黄色葡萄球菌、肺炎链球菌;格兰阴性菌485株,占比37.36%,包括流感嗜血杆菌、肺炎克雷伯杆菌;非典型病原体246株,占比18.95%,为肺炎支原体;病毒190株,占比14.64%。比较革兰阳性菌、病毒与非典型病原体分离率,7岁以上组<0~3岁组<3~7岁组,P<0.05;比较革兰阴性菌分离率,0~3岁组比3~7岁组和7岁以上组都大,P<0.05。药敏结果表明,肺炎链球菌对氨苄西林舒巴坦、头孢唑林、克林霉素、阿奇霉素的耐药率较高,肺炎克雷伯杆菌对氨苄西林舒巴坦、头孢呋辛、头孢噻肟、氨曲南、妥布霉素等的耐药率较高。0~3岁组肺炎链球菌、肺炎克雷伯杆菌对常见抗菌药物的耐药率显著高于3~7岁组、7岁以上组。结论深圳原关外地区儿童下呼吸道感染不同年龄感染率、细菌耐药率差异明显,临床需要结合患儿年龄段、病原菌分布特点、耐药趋势,合理选择抗菌药物。

湘赣边界鹿井地区下寒武统斑点板岩地球化学特征及原岩形成环境

湘赣边界鹿井地区下寒武统斑点板岩是铀矿化重要围岩之一,为研究斑点板岩的地球化学特征、原岩形成构造环境以及对铀矿化的贡献,采集了钻孔中10个新鲜斑点板岩样品进行了镜下观察和主微量元素分析。研究表明,斑点板岩重结晶作用明显,岩石几乎由绢云母、绿泥石、石英等新生矿物组成,其原岩属泥质类岩石。与中国东部泥质岩和华南碳质页岩对比,斑点板岩的CaO、P_(2)O_(5)和烧失量较低,在变质过程中,原岩的有机质成分及多种微量元素、成矿元素已发生了变化或迁出。斑点板岩铀含量为8.12×10^(-6),而Th/U值(2.67)明显高于华南碳质页岩(0.15),斑点板岩铀元素在变质过程中已发生了活化迁移,成为鹿井地区铀源的可能性大大降低。斑点板岩的SiO_(2)/Al_(2)O_(3)、Th/Sc值以及SiO_(2)-(K_(2)O/Na_(2)O)和Th/Sc-Zr/Sc图解指示其原岩具有被动陆缘沉积物源区的特征,形成的构造环境较稳定;V/(Ni+V)值及Ce负异常指示原岩的沉积环境为还原容量较大的边缘海环境。