Uranium Series Chronology of the Late Pleistocene Basalt from the Longgang Volcanoes, Jilin Province

The Longgang volcanic cluster located in Jilin Province belongs to one of the active volcanic regions in northeast China, and has been active in modern times. In view of the multiple eruptions in history, it is very important to determine the age of each eruption for evaluating the volcanic hazards. Two alkaline basalt samples taken from Dayizishan and Diaoshuihu were analyzed with the U-series component dating after magnetic separation. The ages of the two samples are (71±9) ka and (106±13) ka B.P., respectively. These data indicate that there existed intensive eruption activities during the late Pleistocene.

Non-seismic geophysical analysis of potential geothermal resources in the Longgang Block,Northeast China

Although geothermal energy has many clear advantages,including its sustainability and environmentally friendly nature,research into potential geothermal resources across the Longgang Block,Northeast China,has been limited.Here we present the first analysis of the potential geothermal resources in this region that employs joint geological and non-seismic geophysical methods to identify target areas that may be economically viable.We acquire and analyze high-precision gravity,magnetic,and magnetotelluric sounding data,which are constrained using the petrophysical parameters of outcropping rocks across the Longgang Block,to conduct a comprehensive evaluation of the region’s deep geological structures and their geothermal resources potential,with a focus on identifying faults,rock masses,and thermal storage structures.We find that Archean granitic gneiss and Mesozoic rock masses in the deeper section of the Longgang Block possess weak gravity anomalies and high resistivities.We also identify thermal storage structures near these deeper geological units based on their extremely low resistivities.The data are used to infer the dip and depth of known or hidden faults,to constrain the spatial distribution of intrusive rock masses,and to determine the spatial distribution of subsurface thermal storage structures.The potential of the target areas for geothermal resources exploitation is divided into three grades based on contact depths between faults and thermal storage structures,and the scale of their thermal storage structures.Our results suggest that a joint non-seismic geophysical approach can be effective in locating and evaluating geothermal resources in complex geological settings.

Analysis on the Status Quo and Existing Problems of the Longgang River Basin Management

In this paper,status quo of water pollution control in the Longgang River Basin is summarized,and the current status of water environment quality is analyzed,and the main problems in water environment management are discussed.The research aims to provide reference for the management of the Longgang River basin.

The Study on Pyroclastic Deposits in the Longgang Volcanic Swarm, Northeastern China

The Dayizishan scoria cone and Jinlongdingzi scoria cone in the Longgang volcanic swarm, northeastern China are comprised of basaltic fallout tephra that derived from sub-Plinian eruptions. The airborn tephra formed a scoria cone and tephra sheets in geomorphological character. The fallout tephra deposits consist of basaltic scoria, bomb, ultramafic xenolith and lithic fragments. The tephra deposits in the tephra sheets developed plane parallel bedding and graded bedding. The size parameters of tephra changed with distance away from source and the lapse of time regularly. The Dalongwan tuff ring and Longquanlongwan tuff ring in Longgang volcanic swarm are comprised of base surge deposits, formed by phreatomagmatic explosions. The base surge deposits are composed of basaltic lapilli, pisolites and tuff. The sedimentary structure, for instance, dunelike structure, chute and pool structure, U-shaped channel and cross bedding, massive beds and sandwave beds etc. are recognized.

Numerical Simulation and Probabilistic Hazard Assessment of Tephra Fallout at Jinlongdingzi Volcano,Longgang Volcanic Field in Jilin Province

Tephra fallout is an important type of hazard caused by explosive volcanic eruption, and numerical simulation has become a fast and effective approach to assess the dispersion and deposition of tephra fallout. According to the improved 2D diffusion model of Suzuki （ 1983）, we edited a tephra diffusion program that can run in the Windows system. Based on previous data, we simulated the diffusion scope of the Jinlongdingzi volcanic eruption, which is the latest eruption in the Longgang volcanic cluster. The simulated results are in good agreement with the results from measurement in situ, indicating that the model is reliable and the parameters used in the model are suitable. By using wind profiles of ten years, 7, 021 simulations under different wind profiles were carried out, and then probabilistic hazard maps of tephra fallout were constructed for tephra thickness thresholds, lcm and 0.5cm. This study can provide an important scientific basis for volcanic hazard analysis, risk mitigation plans and countermeasures in the Longgang volcanic area.

Interactions of Copper, Evaporite, and Organic Matter and Genesis of Sandstone-Hosted Copper Deposits in the Chuxiong Basin, Yunnan Province

Studies on organic geochemistry indicate that the origin, type and maturity of organic matter are different among coal-bearing, copper-bearing and evaporite formations in the Mesozoic continental Chuxiong Basin, Yunnan, China. A mechanism has been proposed that (1) during the diagenetic mineralization stage the short-chain organic acids dervied from kerogen played an important role in remobilizing copper from source beds, while oils acted as important carrier of copper, and that (2) during the transformation or remolding mineralization stage, meteoric water leached the evaporite layers and formed downward-percolating oxidizing SO42-rich fluids; meanwhile, the copper-bearing fluids migrating upwards along growth faults from the basement was contaminated by the coal-bearing series on the way and formed reducing organic-rich fluids; oxidation-reduction occurred and sulfides formed when the two kinds of fluids met within sandstones.

Thermal evolution characteristics of Triassic coal in Chuxiong Basin and its geological significance

Chuxiong Basin in Yunnan is a typical Mesozoic foreland basin which is enriched in widely distributed Triassic coal resources with thick deposits and of important strategic significance. By applying vitrinite reflectance measurement, inclusion thermometry, fission track dating and EASY% Ro numerical simulation, the Triassic coal thermal evolution history of the Chuxiong Basin was analyzed, and the results were concluded. The vitrinite reflectance of Chuxiong Basin is higher in the west and south in general.Vertically, in the east, west, and north of the basin, the vitrinite reflectance increases with increasing depth, and in the northern part, exceptionally high values occur, and there is no significant regularity in the east. The formation of inclusions inside quartz veins in Chuxiong Basin Triassic coal are unrelated with magmatic hydrothermal fluid, and there are multi-phase inclusions formed in three or four sections of tectonic movements. The main heating period(apparent age) of the Triassic coal is concentrated in the late Cenozoic, during which the coal was subjected to repeated thermal disturbance, resulting in a multimodal distribution of the fission track data, which reveals mild burial features of the early stages of the Late Cenozoic. The Triassic coal of Chuxiong Basin has experienced two major temperature increasing processes, which occurred in the early-mid Yanshan and the early Himalayan, respectively. The first hydrocarbon generation period of coal organic matter occurred in the formation stage of the foreland basin, during which the south and west of the basin generated large amounts of hydrocarbon, but little was preserved. The second generation stage in the Early Himalayan had conditions suitable for high gas accumulation, especially in the western and southern regions. The upper Triassic coal is of moderate burial depth and is less affected by the strike-slip effect. There are key areas of Chuxiong Basin oil and gas exploration, such as the Yanfeng Basin in the north-central, Yongren and Yunlong areas.

Petrology and Geochemistry of Jinlongdingzi Active Volcano—the Most Recent Basaltic Explosive Volcano at Longgang

The Jinlongdingzi active volcano erupted before 1600a, and it is the latest basaltic explosive volcano at Longgang Volcano. Its volcanic products include the Jinlongdingzi volcanic cone (elevation 999.4m), the lava flow and the widely\|spread volcanic pyroclastic sheet (Sihai Pyroclastic Sheet). Jinlongdingzi volcanic rocks are trachybasalts with very similar REE patterns and incompatible element patterns, and their \{\{\}\+\{87\}Sr\}/\{\{\}\+\{86\}Sr\} and \{\{\}\+\{143\}Nd\}/\{\{\}\+\{144\}Nd\} ratios range from \{0.704846\} to \{0.704921\} and from \{0.512619\} to \{0.512646\}, respectively. It is revealed that the trachybasalt has the character of primary magma derived directly from mantle sources with very little evolution and crust contamination during its ascending. The younger mantle xenoliths demonstrate that the mantle source of the Jinlongdingzi Volcano is hydrous, with relatively low temperature.

Crustal thicknesses and Poisson's ratios beneath the Chuxiong-Simao Basin in the Southeast Margin of the Tibetan Plateau

In the Southeast Margin of the Tibetan Plateau, low-velocity sedimentary layers that would significantly affect the accuracy of the H-κ stacking of receiver functions are widely distributed.In this study, we use teleseismic waveform data of 475 events from 97 temporary broadband seismometers deployed by ChinArray Phase I to obtain crustal thicknesses and Poisson's ratios within the Chuxiong-Simao Basin and adjacent area, employing an improved method in which the receiver functions are processed through a resonance-removal filter, and the H-κ stacking is time-corrected.Results show that the crustal thickness ranges from 30 to 55 km in the study area, reaching its thickest value in the northwest and thinning toward southwest, southeast and northeast.The apparent variation of crustal thickness around the Red River Fault supports the view of southeastern escape of the Tibetan Plateau.Relatively thin crustal thickness in the zone between Chuxiong City and the Red River Fault indicates possible uplift of mantle in this area.The positive correlation between crustal thickness and Poisson's ratio is likely to be related to lower crust thickening.Comparison of results obtained from different methods shows that the improved method used in our study can effectively remove the reverberation effect of sedimentary layers.

Planning and Designing of Eco-villages in Urban and Rural Areas——A Case Study of Hongbao Hundred-fruit Eco-village in Chuxiong Yi Autonomous Prefecture, Yunnan Province

The research reviewed connotation, characteristics and significance of urban-rural eco-village and concluded approaches to eco-village planning from site selection, function division, environment and product selection. Finally, a case study of Hongbao Hundred-fruit Eco-village was introduced.

The Major Recessive Calamities Affecting the Wheat Production in Chuxiong Prefecture and Control Countermeasures

The impact of recessive calamities was analyzed,including seasonal drought,cold injury,dry hot wind and aphid in the wheat production of Chuxiong Prefecture,and the countermeasures that prevented and controlled the recessive calamities in a target-oriented way were proposed,including the improvement of basic farmland,the application of organic manure,the promotion of the breed with high stress resistance,the seedling at suitable date,the improvement of control on fertilizing and watering,the enhancement of management on cultivating and controlling disease in time,and the breeding new variety adaptive to local ecosystem,in order to advance the wheat production in a sustainable way.

Late Quaternary Activity of the Chuxiong-Nanhua Fault and the 1680 Chuxiong Ms6 3/4 Earthquake

In this paper,according to the results of the satellite imagery interpretation and field investigation,we study the active features and the latest active times of the ChuxiongNanhua fault,the Quaternary basins formation mechanism,and the relationship between the fault and the 1680 Chuxiong M_S6 3/4earthquake. Several Quaternary profiles at Lvhe,Nanhua reveal that the fault has offset the late Pleistocene deposits of the T2 and T3 terraces of Longchuan river, indicating that the fault was obviously active in late Quaternary. The Chuxiong-Nanhua fault has been dominated by dextral strike slip motion in the late Quaternary,with an average rate of 1. 6-2. 0 mm/a. Several pull apart Quaternary basins of Chuxiong,Nanhua,and Ziwu etc. have developed along the fault.The 1680 Chuxiong M_S6 3/4earthquake and several moderate earthquakes have occurred near the fault. The Chuxiong-Nanhua fault are the seismogenic structure of those earthquakes,the latest fault movement was in the late-Pleistocene,and even the Holocene.In large area,the Chuxiong-Nanhua fault and the eastern Qujiang fault and the Shiping fault composed a set of NW-trending oblique orientation active faults,and the motion characteristics are all mainly dextral strike slip. The motion characteristics,like the red river fault of the Sichuan-Yunnan Rhombic Block southwestern boundary,are concerned with the escaping movement of the Sichuan-Yunnan Rhombic Block.

Characteristics and Mechanism of Upper Permian Reef Reservoirs in the Eastern Longgang Area, Northeastern Sichuan Basin, China

As a typical kind of lithologic reservoirs,reef reservoirs are generally featured by their large single-well reservoir thickness,good reservoir physical properties,and high gas well productivity.The Upper Permian Changxing Formation is an important natural gas exploration target in the Sichuan Basin,which hosts a large reef gas reservoir and is mainly distributed along the Kaijiang-Liangping Trough.Comprehensive analyses are implemented to investigate reservoir characteristics and identify controlling factors of reef reservoirs in Changxing Formation in the Eastern Longgang Area,Northeastern Sichuan Basin,including core,logging,and seismic data analyses.Changxing Formation reservoirs in the study area mainly occur in the reef-shoal complex,which are featured by wide distribution,large thickness and generally good physical properties.Reservoir rocks are dominantly composed of bioclastic dolomite and silty-fine dolomite(with grain phantom structure),while the main reservoir space consists of residual intergranular pores,intergranular dissolution pores,and karst vugs.In the seismic profiles,typical mound-shaped chaotic reflections can be clearly seen.It is suggested by the main reservoir development controlling factor analysis that the distributions of reef reservoirs are typically controlled by sedimentary facies belts,while the scale of the reef-shoal complex is determined by the pene-sedimentary micro-paleo-geomorphology.Dolomitization can not only significantly preserve the primary pores but also enhance the permeability of rocks.Moreover,karstification is the key to high-quality reef-shoal reservoirs.

The metallogenic mechanism of the sandstone-type copper deposits in the Chuxiong Basin, Yunnan Province

The sandstone-type Cu deposits in the Chuxiong Basin occur in the Cretaceous Gaofengsi Formation and the Maotoushan Formation and the orebodies are stratoid and lenticular in form, structurally controlled by their stratigraphical position. Ore structures are dominated by impregnated and striped ones. In addition, it has been observed that copper mineralization is controlled by water-discharge and deformation structures. Orebodies are commonly seen on the gently inclined limbs of the anticline, with the involution front. Copper mineralization shows a distinct zonation. S, Pb isotope and REE data suggest that the copper would stem from the country rocks and the sulfur largely from the lower strata. During diagenesis oxidized Cu-bearing brines derived from the upper parts and reduced brines from the lower parts are involved in metallogenetic reactions in the stress neutral plane, which is the key to the formation of copper deposits in the Chuxiong Basin.

Metamorphic P-T conditions and zircon U-Pb ages of amphibolite in Laojinchang area,southern Jilin Province

The Longgang Block is one of the most important parts of the eastern North China Craton,characterized by extensive Late Neoarchean(~2.5 Ga)granulite facies metamorphism.However,it remains uncertain whether it was influenced by Paleoproterozoic magmatism-metamorphism.The authors provide a comprehensive analysis of amphibolite in Laojinchang area,southern Jilin Province,through petrographic,geochemical,mineralogical,and zircon dating.The main findings are as follows:The mineral assemblage of amphibolite is Hb+Pl+Cpx+Bi+Kf+Q,characteristic of amphibolite facies;zircon U-Pb dating indicates that the metamorphic age of amphibolite is 1834±33 Ma;the amphibolite has geochemical characteristics of calcium alkaline,with depletion of Nb,Ta,Ti and P.The plagioclase in the amphibolite is oligoclase,belonging to acidic plagioclase.It is speculated that the protolith of the amphibolite is diorite;using geothermobarometer,the peak metamorphic P-T conditions of amphibolite are determined to be 536–593℃/3.4–5.0 kbar,and the post-peak conditions are 429–566℃/1.3–3.1 kbar.The above results indicate that the Paleoproterozoic metamorphism has been superimposed on Longgang Block,linked to a new orogenic event on the northern edge of North China Craton.

超越传统:新型设市的出现与乡镇区划建制的走向——对龙港撤镇设市的观察与思考

当前的乡镇区划建制设置具有政权组织事实上的派出化、区划分割的面状化、建制设置的差异化三大特征,这样的乡镇设置模式还存在一些问题。作为区划建制意义上的“市”制在当代中国演化出浙江龙港撤镇设市这一新型设市模式,给基层的乡镇区划建制设置模式带来了较大的冲击。未来的基层区划建制设置应超越传统的乡镇设置模式,实现从行政与自治的纠结走向两者的有机融合,从城乡分治走向城乡合治,从职责不对等走向职责对等,从多层级走向扁平化,从山川交错走向山川形便。

整体智治理念下县域综合行政执法改革的逻辑基础与规制路径——基于对龙港市“一支队伍管执法”的观察

在全国综合行政执法改革实践中,“一支队伍管执法”主要集中在乡镇(街道)层级,县域“一支队伍管执法”是龙港市推进新型城镇化综合改革探索的创新实践。龙港市综合行政执法改革遵循“不建机构建机制,不增层级增协同”的原则,遵循条块协同、整体智治理念,将专业化、数字化、科学化嵌入改革全过程,使法治、协同、效能、服务为民等价值属性统一于县域行政执法领域,形成独具特色的“市直管社区”综合行政执法地方实践。整体智治作为政府数字化转型背景下基层治理模式的创新实践,其核心逻辑表现为将制度和技术嵌入治理过程,重置治理结构、重整治理资源、提升治理质效。构建综合行政执法整体智治的治理机制,通过“执法队伍—执法手段—执法程序—执法监督”全过程闭环、多维度规制路径,能够有效破解当前县域“一支队伍管执法”在执法理念、体系构建、体制重整、规范配套及队伍能力尚存短板的难题,保障县域综合行政执法改革成效。

铸牢中华民族共同体意识的民族节庆机制探析——以楚雄火把节为例

民族节庆符号是一个文化复合体,以其多元的文化底蕴发挥着多重资源性功能而成为一笔铸牢中华民族共同体意识的德育资源。火把节是楚雄的传统民族节日,在推进民族团结进步事业,铸牢中华民族共同体意识的时代背景下,地方党委政府赋予其新的时代内涵,将其建设为民族交往交流交融的平台。节庆活动中强调参与者的多元性,文化的多样性和共享性,努力推动构建各民族相互嵌入式的经济共同体、政治共同体、文化共同体、社会共同体和情感共同体,在此基础上提升铸牢中华民族共同体意识的成效。因此楚雄火把节在铸牢中华民族共同体意识方面的经验和智慧具有较好的启发意义。

楚雄彝族服饰保护和传承的新路径思考

彝族服饰是彝族文化的一个重要组成部分,在商业经济和城市化进程的影响下,传统的彝族服饰日渐衰落。文章采用文献综述和田野调查的方法,分析楚雄彝族服饰日渐消失的成因源于时代困境、大众心理变化、城市化进程与过度商业化的冲击。据此,文章提出加强对彝族服饰的宣传及保护力度、拓展彝族传统服饰文化的传播渠道、保护当地的文化生态等一系列行之有效的策略,推动楚雄彝族民族服饰的保护与传承。

楚雄市洪涝灾害特征及应急管理分析

基于1991~2020年的降水量资料,利用Z指数与小波分析等对楚雄市洪涝灾害的特征进行分析,发现楚雄市洪涝灾害时有发生,呈周期性波动变化,近30年有8年发生洪涝灾害,具有12年的主周期。对楚雄市洪涝灾害应急管理现状进行调查研究,利用PPRR理论从准备、预防、响应和恢复四个阶段对楚雄市洪涝灾害应急管理进行分析,找出目前楚雄市洪涝灾害应急管理体系存在的问题,提出优化措施,为提高楚雄市洪涝灾害防灾减灾能力提供科学依据。