Orientations of palaeotectonic features as a key to understanding the neotectonic block rotation of the Kocaeli peninsula,NW Turkey

Due to northward subduction of Neotethys, the ?stanbul zone collided with the Sakarya zone in northwest Turkey during the early Eocene. Subsequently, this region was subjected to compressional forces during the late Eocene–early Miocene period. Folds, thrusts and reverse faults developed approximately parallel to long axes of the ?stanbul zone. NNW–SSE oriented conjugate strike‐slip faults developed with continued contraction. In addition to the orientations of palaeotectonic features, the morphotectonic, stratigraphic and seismic characteristics expose differences between the northeastern Marmara peneplain and the southern Black Sea highland. This study reports causes of this diversity reflecting the neotectonic evolution of the ?stanbul zone. The diversity is related to the clockwise rotation of the Kocaeli peninsula between two dextral zone‐bounding faults and two sinistral block‐bounding faults. The principle factors of this process were the development of the North Anatolian fault zone (NAFZ) and the related evolution of the Adapazar?–Karasu fault zone (AKFZ), the Bosphorus fault zone (BFZ) and the Northern Boundary fault (NBF).     

潍北-莱州湾凹陷郯庐断裂带新生代走滑特征

横切潍北-莱州湾凹陷郯庐断裂带的地震反射剖面和断裂带内的凹陷断层、沉积相和油气特征,直接或间接显示了郯庐断裂带的延伸、运动性质和活动时限。郯庐断裂带在海域和陆上的几何形态及其组合基本一致,根据切过断裂带的剖面和平面上断层的组合特征,判断其为兼具垂直位移的走滑运动断层系。走滑断裂带的活动控制着凹陷内同构造沉积以及构造样式,表明郯庐断裂带的活动时限具分段性,相当于渤海湾盆地孔店组(E1?2k)-沙四段(E2?3s4)沉积期(古新世-早始新世)-孔店组-沙二段(E2?3s2)沉积期(古新世-始新世)-孔店组-沙一段(E2?3s1)(古新世-渐新世)沉积时期,走滑拉分活动由南向北迁移; 活动方式也由古新世-早始新世的左旋走滑活动,被早始新世之后的右旋走滑活动所替代。     

Analysis of the North Anatolian Shear Zone in Central Pontides (northern Turkey): Insight for geometries and kinematics of deformation structures in a transpressional zone

The western part of the North Anatolian Shear Zone at the southern boundary of the Central Pontides in Turkey, was investigated in the Kurşunlu-Araç area by means of a geological-structural field study. In this area the North Anatolian Shear Zone results in a transpressional deformation zone that extends between two master faults striking parallel to the main shear direction. The main systems of structures identified in the deformation zone appear to be oriented parallel to the directions predicted by Riedel theoretical model. Nevertheless, the strain partitioning is more complicated than predicted by theory. The structural analysis suggests a polyphase deformation characterized by a steady component of transcurrence associated with alternance of compression and extension. Along each of theoretical directions the combination of double verging structures can be observed, with folds and thrust surfaces root into high-angle shear zones, according to flower-type geometries. The discrepancies of directions, kinematics and geometries from theoretical models are due to transpressive and/or transtensive nature of the deformation. According to the observed outcropping structures, we propose a conceptual model for the North Anatolian Shear Zone, interpreting it as a crustal-scale positive flower structure.     

Geophysical constraints of shear zones and geometry of the Hiltaba Suite granites in the western Gawler Craton,Australia

The emplacement of the ca 1590–1575 Ma Hiltaba Suite granites records a large magmatic event throughout the Gawler Craton, South Australia. The Hiltaba Suite granites intrude the highly deformed Archaean‐Palaeoproterozoic rocks throughout the craton nuclei. Geophysical interpretation of the poorly exposed central western Gawler Craton suggests that the region can be divided into several distinct domains that are bounded by major shear zones, exhibiting a sequence of overprinting relationships. The north‐trending Yarlbrinda Shear Zone merges into the east‐trending Yerda Shear Zone that, in turn, merges into the northeast‐trending Coorabie Shear Zone. Several poorly exposed Hiltaba Suite granite plutons occur within a wide zone of crustal shearing that is bounded to the north by the Yerda Shear Zone and to the south by the Oolabinnia Shear Zone. This wide zone of crustal shearing is interpreted as a major zone of synmagmatic dextral strike‐slip movement that facilitated the ascent of Hiltaba Suite granite intrusions to the upper crust. The aeromagnetic and gravity data reveal that the intrusions are ～15–25 km in diameter. Forward modelling of the geophysical data shows that the intrusions have a tabular geometry and are less than 6 km deep.     

渤海湾盆地晚中生代-新生代伸展和走滑构造及深部背景

渤海湾盆地是一个在早白垩世被动裂陷盆地基础上发育起来的新生代主动裂陷盆地, 走滑作用贯穿始终, 特别是在兰聊-盐山断层以东, 使这个裂陷盆地具有鲜明的走滑特征。伸展和走滑作用此消彼长, 伸展构造和走滑构造相互叠加、转换, 垂向上相互叠置、交切, 并由此导致变换带的产生。晚中生代以来太平洋板块向欧亚板块俯冲的方向和速度变化、后撤以及板片窗效应、中始新世印欧板块碰撞导致的地幔上涌是控制盆地形成的深部背景, 郯庐断裂带早白垩世强烈的左行走滑、古新世-早始新世弱的左行走滑以及中始新世后的右行走滑活动也深刻地控制和影响着盆地的发育, 盆地内晚中生代-新生代的伸展和走滑构造的演化则是其浅部响应, 并由此控制着岩浆活动以及油气生成、运聚和分布的时空迁移。     

A fore-arc origin for the Thrace Basin,NW Turkey

Hydrocarbon-bearing Thrace Basin occupies much of the European part of Turkey. The Middle Eocene to Oligocene sequence in the centre of the basin exceeds 9 km in thickness. Based on the stratigraphy, structure and the regional context of this basin, we propose that it developed as a fore-arc basin between the medial Eocene and the Oligocene, above the northward subducting Intra-Pontide Ocean. Its post-Miocene history has been dominated mainly by wrench tectonics resulting from the activity of the now-deactivated northwestern strand. of the present-day North Anatolian fault zone.     

The Thrace Basin: stratigraphic and tectonic-palaeogeographic evolution of the Palaeogene formations of northwest Turkey

The Palaeogene deposits of the Thrace Basin have evolved over a basement composed of the Rhodope and Sakarya continents, juxtaposed in northwest Turkey. Continental and marine sedimentation began in the early Eocene in the southwest part, in the early-middle Eocene in the central part, and in the late Lutetian in the north-northeast part of the basin. Early Eocene deposition in the southern half of the present Thrace Basin began unconformably over a relict basin consisting of uppermost Cretaceous–Palaeocene pelagic sediments. The initial early-middle Eocene deposition began during the last stage of early Palaeogene transtension and was controlled by the eastern extension (the Central Thrace Strike–Slip Fault Zone) of the Balkan-Thrace dextral fault to the north. Following the northward migration of this faulting, the Thrace Palaeogene Basin evolved towards the north during the late Lutetian. From the late Lutetian to the early Oligocene, transpression caused the formation of finger-shaped, eastward-connected highs and sub-basins. The NW–SE-trending right-lateral strike–slip Strandja Fault Zone began to develop and the Strandja Highland formed as a positive flower structure that controlled the deposition of the middle-upper Eocene alluvial fans in the northern parts of the Thrace Palaeogene Basin. Also, in the southern half of the basin, the upper Eocene–lower Oligocene turbiditic series with debris flows and olistostrome horizons were deposited in sub-basins adjacent to the highs, while shelf deposits were deposited in the northern half and southeast margin of the basin. At least since the early Eocene, a NE-trending magmatic belt formed a barrier along the southeast margin of the basin. From the late Oligocene onwards, the Thrace Palaeogene Basin evolved as an intermontane basin in a compressional tectonic setting.     

Geochronological constraints on Caledonian strike–slip displacement in Svalbard,with implications for the evolution of the Arctic

The timing of Svalbard's assembly in relation to the mid‐Paleozoic Caledonian collision between Baltica and Laurentia remains contentious. The Svalbard archipelago consists of three basement provinces bounded by N–S‐trending strike–slip faults whose displacement histories are poorly understood. Here, we report microstructural and mineral chemistry data integrated with ⁴⁰Ar/³⁹Ar muscovite geochronology from the sinistral Vimsodden‐Kosibapasset Shear Zone (VKSZ, southwest Svalbard) and explore its relationship to adjacent structures and regional deformation within the circum‐Arctic. Our results indicate that strike–slip displacement along the VKSZ occurred in late Silurian–Early Devonian and was contemporaneous with the beginning of the main phase of continental collision in Greenland and Scandinavia and the onset of syn‐orogenic sedimentation in Silurian–Devonian fault‐controlled basins in northern Svalbard. These new‐age constraints highlight possible links between escape tectonics in the Caledonian orogen and mid‐Paleozoic terrane transfer across the northern margin of Laurentia.     

Transpressive Structures in the Ghadir Shear Belt,Eastern Desert,Egypt: Evidence for Partitioning of Oblique Convergence in the Arabian‐Nubian Shield during Gondwana Agglutination

Transpressional deformation has played an important role in the late Neoproterozoic evolution of the ArabianNubian Shield including the Central Eastern Desert of Egypt. The Ghadir Shear Belt is a 35 km-long, NW-oriented brittleductile shear zone that underwent overall sinistral transpression during the Late Neoproterozoic. Within this shear belt, strain is highly partitioned into shortening, oblique, extensional and strike-slip structures at multiple scales. Moreover, strain partitioning is heterogeneous along-strike giving rise to three distinct structural domains. In the East Ghadir and Ambaut shear belts, the strain is pure-shear dominated whereas the narrow sectors parallel to the shear walls in the West Ghadir Shear Zone are simple-shear dominated. These domains are comparable to splay-dominated and thrust-dominated strike-slip shear zones. The kinematic transition along the Ghadir shear belt is consistent with separate strike-slip and thrustsense shear zones. The earlier fabric(S1), is locally recognized in low strain areas and SW-ward thrusts. S2 is associated with a shallowly plunging stretching lineation(L2), and defines ～NW-SE major upright macroscopic folds in the East Ghadir shear belt. F2 folds are superimposed by ～NNW–SSE tight-minor and major F3 folds that are kinematically compatible with sinistral transpressional deformation along the West Ghadir Shear Zone and may represent strain partitioning during deformation. F2 and F3 folds are superimposed by ENE–WSW gentle F4 folds in the Ambaut shear belt. The sub-parallelism of F3 and F4 fold axes with the shear zones may have resulted from strain partitioning associated with simple shear deformation along narrow mylonite zones and pure shear-dominant deformation in fold zones. Dextral ENEstriking shear zones were subsequently active at ca. 595 Ma, coeval with sinistral shearing along NW-to NNW-striking shear zones. The occurrence of upright folds and folds with vertical axes suggests that transpression plays a significant role in the tectonic evolution of the Ghadir shear belt. Oblique convergence may have been provoked by the buckling of the Hafafit gneiss-cored domes and relative rotations between its segments. Upright folds, fold with vertical axes and sinistral strike-slip shear zones developed in response to strain partitioning. The West Ghadir Shear Zone contains thrusts and strikeslip shear zones that resulted from lateral escape tectonics associated with lateral imbrication and transpression in response to oblique squeezing of the Arabian-Nubian Shield during agglutination of East and West Gondwana.     

Teleseismic finite-fault inversion of two <Emphasis Type="Italic">M</Emphasis><Subscript>w</Subscript> = 6.4 earthquakes along the East Anatolian Fault Zone in Turkey: the 1998 Adana and 2003 Bingöl earthquakes

The East Anatolian Fault Zone is a continental transform fault accommodating westward motion of the Anatolian fault. This study aims to investigate the source properties of two moderately large and damaging earthquakes which occurred along the transform fault in the last two decades using the teleseismic broadband P and SH body waveforms. The first earthquake, the 27 June 1998 Adana earthquake, occurred beneath the Adana basin, located close to the eastern extreme of Turkey’s Mediterranean coast. The faulting associated with the 1998 Adana earthquake is unilateral to the NE and confined to depths below 15 km with a length of 30 km along the strike (53°) and a dipping of 81° SE. The fixed-rake models fit the data less well than the variable-rake model. The main slip area centered at depth of about 27 km and to the NE of the hypocenter, covering a circular area of 10 km in diameter with a peak slip of about 60 cm. The slip model yields a seismic moment of 3.5?×?10¹⁸ N-m (M_w???6.4). The second earthquake, the 1 May 2003 Bingöl earthquake, occurred along a dextral conjugate fault of the East Anatolian Fault Zone. The preferred slip model with a seismic moment of 4.1?×?10¹⁸ N-m (M_w???6.4) suggests that the rupture was unilateral toward SE and was controlled by a failure of large asperity roughly circular in shape and centered at a depth of 5 km with peak displacement of about 55 cm. Our results suggest that the 1998 Adana earthquake did not occur on the mapped Göksun Yakap?nar Fault Zone but rather on a SE dipping unmapped fault that may be a split fault of it and buried under the thick (about 6 km) deposits of the Adana basin. For the 2003 Bingöl earthquake, the final slip model requires a rupture plane having 15° different strike than the most possible mapped fault.     

Tectonic Evolution of the Wanan Basin,Southwestern South China Sea

Quantitative studies on the extension and subsidence of the Wanan Basin were carried out based on available seismic and borehole data together with regional geological data.Using balanced cross-section and backstripping techniques,we reconstructed the stratigraphic deposition and tectonic evolution histories of the basin.The basin formed from the Eocene and was generally in an extensional/transtensional state except for the Late Miocene local compressoin.The major basin extension ocurred in the Oligocene and Early Miocene(before ~16.3 Ma) and thereafter uniform stretch in a smaller rate.The northern and middle basin extended intensely earlier during 38.6–23.3 Ma,while the southern basin was mainly stretched during 23.3–16.3 Ma.The basin formation and development are related to alternating sinistral to dextral strike-slip motions along the Wanan Fault Zone.The dominant dynamics may be caused by the seafloor spreading of the South China Sea and the its peripheral plate interaction.The basin tectonic evolution is divided into five phases:initial rifting,main rifting,rift-drift transition,structural inversion,and thermal subsidence.     

The role of thrust ramp reactivation in pull-apart mechanism of the Erzincan basin,North Anatolian Fault Zone,Turkey

The new field data obtained from the southwestern margin of the Erzincan pull-apart basin located on the eastern segment of North Anatolian Fault Zone indicate that the opening of the basin is not only controlled by pull-apart mechanism but also by a lateral ramp structure associated with SSE-NNW Late Miocene thrusting along the Sivas Basin. The fault bordering the southwestern margin of the basin is the lateral part of the Karada thrust that is the roof thrust of the Sivas fold-thrust system, rather than a segment of the North Anatolian Fault Zone. The Erzincan basin was nucleated as a lateral ramp basin during the Pliocene on the lateral ramp-related folds and expanded by the pull-apart opening mechanism between two segments of the North Anatolian Fault Zone. The WSW-ENE pull-apart opening of the basin was recorded by the Pliocene lacustrine-fluvial sediments and Quaternary volcanics as listric normal faulting.     

Late Eocene-early Miocene palaeogeographic evolution of central eastern Anatolian basins,the closure of the Neo-Tethys ocean and continental collision

In central eastern Anatolia which is located between Eurasia and Africa, the study of basin developments between late Eocene and early Miocene is of great importance for understanding the process of the closure of the Neo-Tethys Ocean and the formation of strike-slip faults and regional uplift. To study these, three basins were selected: the Sivas-Erzincan, Gürün-Akkisla-Divrigi (GAD), and Malatya basins. The study proposes that the opening of the GAD basin played a key role in the formation of the Ecemis fault, which started developing at the end of early Miocene, and in mountain uplift. All these basins are situated on continental blocks and oceanic crust, arranged from north to south as the Sakarya continent, the Izmir-Ankara-Erzincan ocean (Northern Neo-Tethys), the Kirsehir continent, the inner Tauride ocean, the Munzur-Binboga block, the Maden (=Berit) ocean, the Bitlis-Pütürge block, the Çüngüs ocean and the Arabian continent.The findings indicate that late Eocene-early Miocene successions in these basins were not deposited in foreland basins formed in front of the thrust faults associated with the closure of the ocean, as stated in previous studies. Rather, they were deposited in forearc and backarc basins related to the subduction which was effective until the end of early Miocene. The Sivas-Erzincan and Malatya basins, located on the inner Tauride and Maden (=Berit) oceans, were forearc basins, while the GAD basin situated on the Munzur-Binboga block was a backarc basin. These basins have parallel developments up to the end of early Miocene. While marine sediments were deposited in the Malatya and Sivas-Erzincan basins between late Eocene and early Miocene, terrestrial units began to settle in the GAD basin from the late Eocene and the deposition there is continuous until the end of the early Miocene.Collision of the Arabian and the Anatolian plates at the end of early Miocene (16-18 Ma) produced the left-strike slip Ecemis fault zone, which caused the lateral slip of sedimentary units in the Sivas-Erzincan and GAD basins over hundreds of kilometers. This event produced the first westward tectonic escape of the Anatolian plate prior to the north Anatolian fault (NAF) and the east Anatolian fault (EAF). The Gürün region located in the GAD basin was exhumed in late Miocene and this basin was broken. The Gürün region, which remains on the rising part of the Munzur-Binboga block, is not a different basin as stated earlier, but it is a part of the GAD basin, representing the central part of the GAD basin lake, as indicated by the fine grained deposits (limestones and clay) that occur in the Gürün area.     

Latest Miocene and Pleistocene ages of faulting, determined by 40Ar/39Ar single-crystal dating of airfall tuff and silicic extrusives of the Erciyes Basin, central Turkey: evidence for intraplate deformation related to the tectonic escape of Anatolia

The Ericiyes Basin is a trans‐tensional basin situated 20 km north of the regional Ecemi? Fault Zone. Recently it has been hypothesized that faulting within the Erciyes Basin links with the Ecemi? Fault Zone further south as part of a regional Central Anatolian Fault Zone. New ⁴⁰Ar/³⁹Ar dating of volcanic and volcaniclastic rocks adjacent to faults, both along the margins and in the centre of the Erciyes Basin, constrains the timing of basin inception and later faulting. Extensional faulting occurred along the eastern and western margins of the basin during the Early Messinian (latest Miocene). Sinistral and minor normal faulting were active along the axis of the basin during the early Pleistocene. These fault timings are similar to those inferred for the Ecemi? Fault Zone further south, and support the hypothesis that faulting within the Erciyes Basin and the Ecemi? Fault Zone are indeed linked.     

PALEOCENE—MIDDLE EOCENE DEXTRAL STRIKE-SLIP DEFORMATION AND ITS TECTONIC IMPLICATION IN THE WESTERN YUNNAN, CHINA

PALEOCENE—MIDDLE EOCENE DEXTRAL STRIKE-SLIP DEFORMATION AND ITS TECTONIC IMPLICATION IN THE WESTERN YUNNAN, CHINA     

Tower Hill gold deposit,Western Australia: An atypical,multiply deformed Archaean gold‐quartz vein deposit

The Tower Hill gold deposit is distinguished from most Archaean lode deposits of the Yilgarn Craton by virtue of its formation early in the regional deformation history and its consequent deformation. The deposit is located in ultramafic schist, adjacent to the contact with a small pluton of biotite monzogranite that intrudes pervasively foliated granodiorite, the dominant component of the Raeside Batholith. Gold, accompanied by local concentrations of bismuth minerals and molybdenite, occurs in a number of quartz vein ‘packages‘. Mineralised quartz veins at Tower Hill lie within an envelope of potassic alteration (talc‐biotite‐chlorite‐pyrite schist), up to several hundred metres wide. They are spatially and temporally associated with the biotite monzogranite and felsic porphyry intrusions, and their deformed equivalents. The deposit lies in a broad zone of ductile deformation (the Sons of Gwalia Shear Zone). Within the altered ultramafic schist, thin units of felsic schist, derived from biotite monzogranite and felsic porphyry, provided sites of contrasting competency that localised quartz vein formation. The mineralised quartz veins were subsequently deformed during alternating periods of shortening and extension, probably related to the syntectonic, solid‐state emplacement of the Raeside Batholith. These deformations pre‐dated strike‐slip movement on the Cemetery Fault, which truncates the ductile fabrics of the Sons of Gwalia Shear Zone, south of Tower Hill. In terms of the regional deformation history, gold mineralisation at Tower Hill formed during early D₂ (regional upright folding); subsequent deformation of the orebody pre‐dated D₃ (strike‐slip movement on the Cemetery Fault). The nearby Sons of Gwalia and Harbour Lights deposits also probably formed at an early stage, in contrast to most lode gold deposits in the Yilgarn Craton, which formed during or after D₃.     

An Alleghenian orocline: the Asturian Arc,northwestern Spain

The Asturian Arc was produced in the Early Permian by a large E–W dextral strike–slip fault (North Iberian Megashear) which affected the Cantabrian and Palentian zones of the northeastern Iberian Massif. These two zones had previously been juxtaposed by an earlier Kasimovian NW–SE sinistral strike–slip fault (Covadonga Fault). The occurrence of multiple successive vertical fault sets in this area favoured its rotation around a vertical axis (mille-feuille effect). Along with other parallel faults, the Covadonga Fault became the western margin of a proto-Tethys marine basin, which was filled with turbidities and shallow coal-basin successions of Kasimovian and Gzhelian ages. The Covadonga Fault also displaced the West Asturian Leonese Zone to the northwest, dragging along part of the Cantabrian Zone (the Picos de Europa Unit) and emplacing a largely pelitic succession (Palentian Zone) in what would become the Asturian Arc core. The Picos de Europa Unit was later thrust over the Palentian Zone during clockwise rotation. In late Gzhelian time, two large E–W dextral strike–slip faults developed along the North Iberian Margin (North Iberian Megashear) and south of the Pyrenean Axial Zone (South Pyrenean Fault). The block south of the North Iberian Megashear and the South Pyrenean Fault was bent into a concave, E-facing shape prior to the Late Permian until both arms of the formerly NW–SE-trending Palaeozoic orogen became oriented E–W (in present-day coordinates). Arc rotation caused detachment in the upper crust of the Cantabrian Zone, and the basement Covadonga Fault was later resurrected along the original fault line as a clonic fault (the Ventaniella Fault) after the Arc was completed. Various oblique extensional NW–SE lineaments opened along the North Iberian Megashear due to dextral fault activity, during which numerous granitic bodies intruded and were later bent during arc formation. Palaeomagnetic data indicate that remagnetization episodes might be associated with thermal fluid circulation during faulting. Finally, it is concluded that the two types of late Palaeozoic–Early Permian orogenic evolution existed in the northeastern tip of the Iberian Massif: the first was a shear-and-thrust-dominated tectonic episode from the Late Devonian to the late Moscovian (Variscan Orogeny); it was followed by a fault-dominated, rotational tectonic episode from the early Kasimovian to the Middle Permian (Alleghenian Orogeny). The Alleghenian deformation was active throughout a broad E–W-directed shear zone between the North Iberian Megashear and the South Pyrenean Fault, which created the basement of the Pyrenean and Alpine belts. The southern European area may then be considered as having been built by dispersal of blocks previously separated by NW–SE sinistral megashears and faults of early Stephanian (Kasimovian) age, later cut by E–W Early Permian megashears, faults, and associated pull-apart basins.     

Miocene formations and NE-trending right-lateral strike–slip tectonism in Thrace,northwest Turkey: geodynamic implications

In the Thrace Peninsula, Neogene units were deposited in two areas, the Enez Basin in the south and the Thrace Basin in the north. In the southwesternmost part of the peninsula, upper lower–lower upper Miocene continental to shallow marine clastics of the Enez Formation formed under the influence of the Aegean extensional regime. During the last stage of the transpressional activity of the NW-trending right-lateral strike–slip Balkan–Thrace Fault, which had controlled the initial early middle Eocene deposition in the Thrace Basin, a mountainous region extending from Bulgaria eastwards to the northern Thrace Peninsula of Turkey developed. A river system carried erosional clasts of the metamorphic basement southwards into the limnic depositional areas of the Thrace Basin during middle Miocene time. Deposition of fluvial, lacustrine, and terrestrial strata of the Ergene Formation, which conformably and transitionally overlie the Enez Formation, began in the late middle Miocene in the southwest part and in the late Miocene in the north‐northeast part of the basin. Activity along the NE-trending right-lateral strike–slip faults (the Xanthi–Thrace Fault Zone) extending from northeast Greece northeastwards through the Thrace Peninsula of Turkey to the southern shelf of the western Black Sea Basin began during the middle Miocene in the northern Aegean, at the beginning of the late Miocene in the southwest part, and at the end of the late Miocene in the northeast part of the Thrace region. Although the Neogene deposits in the Thrace Basin were evaluated as the products of a northerly fault, our data indicate that the NW-trending northerly fault zone became effective only during the initial stage of the basin development. The later stage deposition in the basin was controlled by the NE-trending Xanthi–Thrace Fault Zone, and the deposits of this basin progressively evolved north/northeastwards during the late Miocene. During the late early Miocene–late Miocene interval, extension within the Thrace region was part of the more regional Aegean extensional realm, but from latest Miocene time, it has been largely decoupled from the Aegean extensional realm to the south.     

云南金顶超大型铅锌矿床的成矿地质背景

采用构造－沉积综合分析的方法，研究了金顶超大型铅锌矿床成矿的盆地、构造和深部地质背景。研究表明，控矿的古新世－中始新世盆地为走滑拉张盆地，研究区先后经历了古新世－中始新世早期的走滑和拉伸，中始新世－渐新世的挤压推覆和中新世的隆升和走滑，分析了盆地演化、沉积体系、同生断裂活动和逆冲推覆等对金顶超大型铅锌矿床的控制作用，探讨了可能的成矿过程。     

北黄海盆地构造运动学解析

以最新的地质 地球物理资料和北黄海盆地构造几何学特征为基础,采用盆地反演模拟与宏观分析相结合的方法,系统解析了北黄海盆地的构造运动学特征。研究表明,北黄海盆地在中、新生代时期经历了水平伸展、水平挤压、相对平移(走滑)以及垂直差异升降等几种运动型式,其中,水平伸展运动和垂直差异升降运动是北黄海盆地构造运动及形成演化的主体。水平伸展运动可以划分为J3-K1、E2和E3三个主要“伸展事件”,并控制着盆地的成盆演化,其南北向伸展强度均东强西弱,东西向最大伸展强度自中生代到新生代由东向西迁移。水平挤压运动主要有晚白垩世和渐新世末-中新世初期两期。相对平移(走滑)运动伴随水平伸展运动和水平挤压运动发生,使多数NNE向、NW向断裂具有相对压扭或张扭平移(走滑)性质,其中尤以NNE向断裂更为明显。垂直差异升降运动具有“幕式”渐进之特点,晚侏罗世、早白垩世、始新世、渐新世以及中新世中晚期以来为沉降期,其中尤以始新世的沉降速率最大,晚白垩世、古新世、中新世早期为抬升剥蚀期;盆地的中、新生代沉降作用具有明显的自东向西迁移规律:东部坳陷以中生代沉降作用最为显著,中部坳陷主沉降期为始新世,而西部坳陷的快速沉降主要发生在始新世,并一直持续到渐新世。