Unstable Rifts,a Leaky Transform Zone and a Microplate:Analogues from South Iceland

A structural analysis was undertaken in the South Iceland Seismic Zone (SISZ) transform zone, and in the Hreppar Microplate (HMP) located between the propagating Eastern Rift Zone (ERZ) and the receding Western Rift Zone (WRZ). The age of the oceanic crust in these areas is 3.4 Ma to present. About 20,000 fracture segments on aerial images reflect the dominance of NNE extensional structures in the WRZ. Around 9,000 basement faults, intrusions, secondary fractures, surface ruptures of earthquakes, and leakages were mapped in the outcrops of the HMP and the SISZ. About 23% of these fractures strike NNE, while 77% are dominantly northerly dextral and ENE sinistral, and secondarily E-W, WNW and NW sinistral strike- and oblique-slip structures, forming a Riedel shear pattern typical of a transform zone. Dyke injections into Riedel shears indicate a leaky transform zone. Fractures reactivated, accumulated slip, and re-opened for fluid flow. The ENE faults dip mostly to the southeast and could be the present boundary of the SISZ to the north. A 10 - 30 km wide ENE structural zone hosts a valley to the east, which could be deeper in the west. This ENE zone contains all the earthquakes, dominant ENE rivers, frequent ENE secondary fractures, and is likely the active part of the SISZ. The HMP does not show rotation since 3.4 Ma despite being between two rift segments. Future propagation/recession of the rift segments along their N55°E sections would cause a migration and a clockwise rotation of the SISZ from ENE to E-W. The boundary faults of the SISZ would then be E-W, with unchanged internal Riedel shears, compensating its sinistral motion. Insights into complexities of diverging plate boundaries are critical for resource management in such tectonic contexts.

Structures and Styles of Deformation in Rift,Ridge,Transform Zone,Oblique Rift and a Microplate Offshore/Onshore North Iceland

The diverging plate boundaries in North Iceland and its shelf display a complex tectonic at the Kolbeinsey Ridge (K-R), the Northern Rift Zone (NRZ), and the Tj?rnes Fracture Zone containing the Grímsey Oblique Rift (GOR), the Húsavík-Flatey Fault (HFF), and the Dalvík Lineament (DL). While active deformation is well-known, the structural pattern is sporadically mapped and a comprehensive account of the upper Tertiary-present deformation is not fully at hand. To address the gaps, this paper provides new regional tectonic maps with continuous coverage, and detailed analyses of the deformation. Faults, open fractures, prominent joints and volcanic edifices were identified on Multibeam/Single beam, Spot 5, and Digital Elevation Model, and subjected to multidisciplinary structural analysis and correlation with selected data. Some of the results are: 1) Six sets constitute the structural pattern. The N-S rift-parallel normal faults are 1/3, and the shear fractures of the transform zone and the oblique rift 2/3 of the fracture population. The en échelon arrangements above deep-seated shear zones indicate dextral slip on WNW to NW, and sinistral slip on NNE to ENE faults, conformable with earthquake data. 2) During the polyphase tectonic, the six sets led to basin and horst formation, block compartmentalisation, rotation, horsetail splay, rhomb-graben in relay zone of strike-slips, and volcanism. 3) Listric faults are absent and the steeply-dipping faults are antithetic, synthetic, or form extensional flower structures above 4 km depth. The Plio-pleistocene/present syn-sedimentary deformation caused a deep half graben in the Eyjafjarearáll Basin (Ey), fault growth, rollover, and sediment onlaps, with some of the faults still active. 4) The plate boundaries of K-R/Ey, GOR/?xarfjreur/NRZ, and DL delimit a major microplate labelled here as Grímsey-Tj?rnes-Dalvík. 5) The WNW earthquake cluster in GOR corresponds either to a blind horsetail splay fault or to initiation of a transform segment parallel to the HFF. The described tectonic-sedimentary-magmatic deformation is relevant to other diverging plate boundaries where similar sets control the hydrocarbon and geothermal resources.

Tectonic Control of the Theistareykir Geothermal Field by Rift and Transform Zones in North Iceland:A Multidisciplinary Approach

This paper presents a multidisciplinary structural analysis of a 165 km2 area in the Northern Rift Zone and the Tjörnes Fracture Zone of Iceland, and unravels the tectonic control of the Theistareykir geothermal field and its surroundings. About 10729 fracture segments (faults, open fractures, joints) are identified in the upper Tertiary to Holocene igneous series. The segments were extracted from aerial images and hillshade, and then analyzed in terms of number of sets, geometry, motions, frequency, and relative age. The correlation with surface geothermal manifestations, resistivity, earthquakes, and occasional well data reveals the critical regional and local fractures at the surface, reservoir level and greater depth. The main conclusions of this study are: 1) The structural pattern consists of N-S rift-parallel extensional fractures and the Riedel shears of the transform zone striking NNE, ENE, E-W, WNW and NW, which compartmentalize together the blocks at any scale. 2) The en échelon segmentation shows strike and oblique slips on the Riedel shears, with a dextral component on the WNW and NW planes and a sinistral component on the NNE to ENE faults. 3) Fractures form under the influence of the transform mechanism and the effect of rifting becomes significant only with time. 4) The WNW dextral oblique-slip Stórihver Fault of the transform zone has a horsetail splay that extends eastwards into the geothermal field. There, this structure, along with few NW, ENE, NNE and N-S fractures, controls the alteration, alignment of fumaroles, emanating deep gases. These fractures also rupture during natural or induced earthquakes. 5) The resistivity anomalies present en échelon geometries controlled by the six fracture sets. These anomalies display clockwise and anticlockwise rotations within the upper 8 km crustal depth, but at 8 km depth, only three sets (the N-S rift structures, and the E-W and the NW Riedel shears) are present at the rift and transform plate boundaries. Results of this study are relevant to resource exploration in other complex extensional contexts where rift and transform interact.ööö

Understanding ductile-to-brittle transition of metallic glasses from shear transformation zone dilatation

A theoretical model that takes into account the flee-volume aided cooperative shearing of shear transformation zones （STZs） is developed to quantitatively understand the ductile-to-brittle transition （DBT） of metallic glasses. The STZ dilatational strain is defined as the ratio of STZ-activated free volume to STZ volume itself. The model demonstrates that the STZ dilatational strain will increase drastically and exceed the characteristic shear strain of STZ as temperature decreases below a critical value. This critical temperature is in good agreement with the experimentally measured DBT temperature. Our results suggest that the DBT of metallic glasses is underpinned by the transition of atomic-cluster motions from STZ-tvpe rearrangements to dilatational processes （termed tension transformation zones （TrZs））.

A review of POPs in the fragile critical zone of the Tibetan Plateau: transport and transformation

The near-surface environment of the Tibetan Plateau is a fragile critical zone. Our understanding of the transport and transformation of persistent organic pollutants(POPs) in the ecosystem has significantly improved with research conducted in recent decades. In the current study,POP concentrations in soils logarithmically decreased and fractionated with increasing distance from the source area,patterns attributed to air–soil exchange. Transport from soils resulted in the enrichment of POP concentrations in plants and sediments. The enantiomeric fraction indicated that transformation of POPs in soils was significantly correlated with altitude. At the same time, the chiral signature of POPs in soils was maintained from soils to sediments, while the chiral transformation from soils to plants was found to be complex.

MICROSTRUCTURE TRANSFORMATION IN THE WELDING HEAT AFFECTED ZONE OF 800MPa GRADE ULTRA FINE STRUCTURED STEEL

The transformation behavior and microstructure development in the heat affected zone(HAZ) of 800MPa grade ultra fine structured steel was investigated. It was found thatthe HAZ has intermediate temperature transformation characteristics in a wide rangeof cooling rates, with the bainite sheaves consisting of bainite ferrite plates withoutcarbide precipitation and retained austenite in the fast cooling regime. At relativelyhigh cooling rates, which corresponded to low heat inputs, the hardness of the simulatedHAZ was above that of the base metal. When the cooling rate was below 9℃/s, thewelding HAZ would have an obvious softening. The analysis of transformation ratesin continuous cooling processes was completed by numerical differential method. Theresult indicated that the microstructure transformation rate of the HAZ in 800MPagrade ultra fine structured steel changed sharply to slow speeds when the cooling timet_(8/5) is longer than 7s.

On Radiation Boundary Conditions and Wave Transformation Across the Surf Zone

The purpose of this paper is to extend the validity of Li's parabolic model (1994) by incorporating a combined energy factor in the mild-slope equation and by improving the traditional radiation boundary conditions. With wave breaking and energy dissipation expressed in a direct form in the equation, the proposed model could provide an efficient numerical scheme and accurate predictions of wave transformation across the surf zone. The radiation boundary conditions are iterated in the model without use of approximations. The numerical predictions for wave height distributions across the surf zone are compared with experimental data over typical beach profiles. In addition, tests of waves scattering around a circular pile show that the proposed model could also provide reasonable improvement on the radiation boundary conditions for large incident angles of waves.

Study on Migration and Transformation Rule of Organic Pollutants (COD) in Aerated Zone

Collecting waste water with a certain c onc entration of organic pollutants COD (chemical oxygen demand), static adsorption, static biodegradation and dynamic soil column experiments were made in laborato ry, we researched migration and transformation of COD in aerated zone, and put f orward a mathematical model showing the process. The results show that adsorptio n of organism in aerated zone is linear, which is represented by Henry's law s =K dc+s d, adsorption coefficient K d=0.069 3; biodegradati on diagram accord basically with first order kinetics equation c=c 0e -K 1t , biodegradation coefficient K 1 = 0.049 9 d -1 ; dispersio n coefficient D= 0.002 42 m 2/d in experiments. The migration and transform ation of organic pollutants (COD) in aerated zone jointly result from many f actors such as dispersion, adsorption and biodegradation etc..

国家公园生态产品价值转化体系

生态产品价值实现机制是以生态保护促进绿色发展的重要机制,社会生态需求无限性和多层级性同国家公园生态供给有限性之间的矛盾,需要通过市场化机制的建立实现平衡,生态韧性与交换价值理论是国家公园生态产品价值实现的理论基础。从社会生态需求角度建立国家公园生态服务产品分类体系,为国家公园生态服务产品供需平衡的精准调控奠定了基础,以供定需,以需引供。特质性、时代性、公益性、可持续性是国家公园生态产品价值转化的基本原则,国家公园生态产品价值转化具有时间、空间、类型、层级等4个维度的特征,3类5级是其基本转化体系,随时空变化、资本投入不同而不同,物质类、精神类、知识类产品是体现国家公园特质的3类生态服务产品,公共性、准公共性与经营性是国家公园生态服务产品的3个基本属性,空间梯度与转化效率是生态产品价值实现程度和质量的重要评价指标,也是国家公园管控分区和功能分区合理性及其管理绩效评价的重要依据。

逆冲-走滑作用叠加的复合构造变形机制砂箱模拟研究:以张家口-蓬莱断裂带渤海段为例

逆冲构造体受走滑作用影响形成新的复合构造体系在自然界中较为常见。新生代以来张家口-蓬莱断裂带渤海段的左旋走滑运动,改造了渤海湾盆地内燕山期挤压运动形成的逆冲构造。北西向的张家口-蓬莱断裂带渤海段受新生代以来太平洋板块俯冲驱动,与共轭的北东向郯庐断裂带共同控制了渤海湾盆地现今的构造样式,同时又是地震多发区和油气聚集区。本文通过砂箱模拟实验,研究不同走滑速率不同基底强度条件下,逆冲推覆构造受走滑作用改造的复合构造演化机制。实验结果显示,在挤压背景下,实验模型中先产生一系列的逆冲断层,形成逆冲推覆构造和冲起构造;叠加走滑作用后,走滑断层切割先存逆冲断层,具有明显的负花状构造特征。剖面上看,走滑速率越大,则断层数量越多,断层断距更大,花状构造更为复杂。在局部塑性基底模型中,无叠加的走滑构造区可形成断陷。结合研究区构造演化过程,模拟结果与张家口-蓬莱断裂带渤海段构造演化过程具有一定相似性,尤其沙北断裂、沙东断裂内部花状构造发育最为典型。走滑断裂对构造圈闭具有一定的控制作用,本模型可对逆冲叠加走滑复合区域的构造演变及动力机制分析提供参考和借鉴。

大型走滑转换带对油气分布差异性控制作用: 以西非科特迪瓦盆地为例

科特迪瓦盆地位于西非赤道段,发育大型走滑转换带,为典型的转换型被动陆缘盆地,是当前油气勘探热点区域,勘探潜力巨大,但油气平面分布、纵向富集均存在较大的差异性。基于前人研究,利用井、震资料并结合近年来新发现油气藏数据,重点从构造和沉积2个方面阐述了走滑转换带对油气分布差异性的控制作用。研究表明,盆地经历了陆内裂谷、洋陆转换和被动陆缘3个主要的构造-沉积演化阶段,形成了总体上“西窄东宽”的斧型构造格局特征,西部为陡窄转换边缘,东部为宽缓离散边缘,中部为过渡边缘,宏观上控制了油气“西少东多”的分布规律。走滑转换作用应力主要响应区为中部过渡边缘,中部隆起马尾带发育大量的构造圈闭,具有南北双向供烃特征,控制了北部凸起阿尔比构造油气藏的形成与分布。走滑转换作用形成的古地貌对转换早期上阿尔比-森诺曼和转换晚期土伦阶储层的空间展布特征均有重要的控制作用,内斜坡洼陷(盆地)往往是最为有利的富砂处,同时也是最有利的地层-岩性圈闭发育区,油气分布与沉积体系展布具有较好的一致性,即转换控储,分布控藏。

渤中8-4油田“S”型走滑转换带特征及其对浅层油气侧封的控制作用

新构造运动在渤海海域表现强烈,形成了渤中凹陷特有的走滑构造体系和浅层油气藏。前人研究集中在走滑运动论证和走滑转换带类型探讨上,缺乏对走滑构造带控藏作用的精细研究。利用地震资料,结合油田实例,探讨了渤中8-4油田走滑转换带特征和对油气侧封的控制作用。研究认为,渤中8-4油田主断裂为“S”型走滑转换带,发育释压带和增压带两类转换带。释压带地层陡,圈闭不发育,是油气由深向浅的充注段;增压带地层缓,背形特征清晰,低幅断鼻、断块圈闭集中发育,为油气汇聚区。建立了走滑断裂封闭指数以定量表征走滑转换带的侧封能力,通过近20个油田的统计分析,认为可以把走滑断裂封闭指数4作为走滑断层侧封的临界值。该成果为富砂背景下的浅层油气勘探工作提供了一种新的方法和思路。

基于“企业—行业—开发区”的淮海经济区产业空间集聚特征

企业—行业—开发区不同尺度的产业协同对区域可持续发展具有重要意义。该文基于企业尺度数据,采用标准差椭圆、核密度分析、多距离空间聚类分析、平均最近邻指数,从企业—行业—开发区多尺度视角分析了2002—2022年淮海经济区产业空间集聚特征。结果表明:①研究期间淮海经济区产业总体上呈现“西北—东南”空间集聚格局,表现为以济宁、徐州、临沂、宿迁为核心的点状集聚形态;②淮海经济区以商贸物流、科技研发、装备制造为典型优势行业,产业存在空间分布、集聚尺度与集聚强度差异;③国家级开发区产业集聚指向性比省级开发区更强,高级化态势更显著,经济技术开发区产业集聚水平高于高新技术开发区;④淮海经济区产业空间集聚具有企业—行业—开发区协同特征。

大数据综合试验区对企业创新的影响研究——来自中国上市公司的经验证据

本文以2007—2021年我国上市公司为样本,采用多期双重差分法(DID)检验大数据综合试验区对企业创新的影响及作用机制。实证结果显示,大数据综合试验区可以有效提升企业创新水平;在进行平行趋势检验、安慰剂检验以及更换被解释变量等一系列稳健性检验后,该结论依然成立。机制检验发现,企业数字化转型意愿、企业高技能人才集聚水平以及政策支持力度可以正向调节大数据综合试验区与企业创新之间的关系。此外,大数据综合试验区设立对企业创新的促进作用存在异质性,本文发现大数据综合试验区建设赋能企业创新的政策效应在知识密集型行业和东部地区、高管具有海外经验与金融背景以及两职分离的企业更加显著。本文有助于厘清大数据综合试验区建设对企业创新的影响,为我国以数字技术驱动企业创新、建立区域协调发展新机制提供理论支持与政策建议。

数字经济对制造业转型升级的影响——基于国家大数据综合试验区的拟自然实验

将国家大数据综合试验区设立视为数字经济发展的一个拟自然实验,利用我国31个省(自治区、直辖市)2003—2020年的面板数据,从制造业结构合理化和制造业结构高级化两个维度,实证分析了数字经济发展对地区制造业转型升级的影响及作用机制。研究结果显示:无论是否纳入控制变量,数字经济发展对制造业转型升级具有显著正向效应;在替换被解释变量和剔除部分样本后,数字经济对制造业转型升级的促进作用仍然非常稳健;数字经济发展主要通过创新激励效应和需求拉动效应促进制造业结构合理化和高级化。

保税区与出口加工区对工业绿色转型影响研究

保税区与出口加工区不仅是工业发展政策的空间载体,更是驱动地区工业绿色转型的关键。本文基于2004—2022年省级面板数据,采用双向固定效应模型实证分析了保税区和出口加工区对地区工业绿色转型的影响及其作用机制。结果表明:保税区的产业集聚效应、FDI技术溢出效应和制度溢出效应促进地区工业绿色转型,出口加工区的产业集聚效应促进地区工业绿色转型;保税区对地区工业绿色转型的影响存在明显的地区和时间异质性;长江经济带发展战略联动效应放大了保税区和出口加工区对地区工业绿色转型的影响;保税区和出口加工区对地区工业绿色转型的影响存在明显的协同效应。各地区政府应在保税区和出口加工区内培育产业集群,着力推动产业转型并发挥技术创新引领作用。

绿色融合式治理:城乡结合部社区生态治理的空间转向与生成机制

城乡结合部社区作为城市化进程中的一个过渡形态,其“亦城亦乡”的混合形态为城乡社区治理带来了巨大挑战。如何实现以人为本的社区发展治理与生态治理的有机融合,进而推动我国新型城市化高质量发展,成为值得深入探讨的重大议题。本研究以成都市公园社区示范点为例,以马克思主义的社会空间理论为视角,以“空间断裂—空间修复—空间适配”为分析框架。研究发现:在快速城市化进程中,生态空间与生产空间、生活空间相“切割”引发了城乡结合部社区的“新陈代谢断裂”;通过空间修复与空间营造,城乡结合部社区实现了从生产、生活和生态空间分类而治转向空间适配的绿色融合式治理。“绿色融合式治理”是一种以“绿色”生态价值观念为准则的社区治理创新机制,包含“多元主体联动”“空间尺度再造”与“空间资源融合”的内在机理,不仅拓展和丰富了社区治理的理论维度,更生动展现了中国式现代化对于西方现代化的超越。“绿色融合式治理”不仅是中国城乡社区治理的机制创新,也可为世界可持续发展贡献中国智慧和中国方案,进一步推进全球生态正义的实现。

产业转型升级视角下智慧城市建设策略研究——以武汉经济技术开发区为例

文章分析了开发区转型升级与智慧城市建设的关联逻辑,提出了产业转型升级视角下开发区开展智慧城市建设的要点,并以武汉经济技术开发区(以下简称武汉经开区)为例,提出产业转型视角下智慧城市规划提升的对策建议,有助于推动开发区向更高阶的城市综合功能区形态转型。

浅谈开发区数字化转型之路——基于山西综改区一体化探索

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