Late Miocene–Quaternary volcanism, tectonics and drainage system evolution in the East Carpathians, Romania

Middle Miocene (Sarmatian) convergence created the fold and thrust belt of the Eastern Carpathians of Romania, which subsequently experienced post-collisional crustal deformation combined with calc-alkaline and alkalic-basaltic volcanism in late Miocene–Quaternary time. This deformation led to the rise of the Cǎlimani–Gurghiu–Harghita volcanic mountains and to the subsidence of the N–S-oriented intramontane Borsec/Bilbor–Gheorgheni–Ciuc and Braşov pull-apart basins, and the E-oriented monocline-related Fǎgǎraş basin. The regional drainage network is the composite of:

(1) Older E-, SE- and S-flowing rivers, which cross the Carpathians, radiate towards the foreland and were probably established during the Middle Miocene (Sarmatian) collision event.

(2) A more recent drainage system related to the contemporaneous development of the volcanoes and intramontaneous basins, which generally drains westward into the Transylvanian Basin since late Miocene time and has been capturing the older river system.

The older river drainage system has also been modified by Late Pliocene–Quaternary folding, thrusting and monoclinal tilting along the Pericarpathian orogenic front and by reactivated transverse high angle basement faults, which cross the Eastern Carpathian foreland.     

东地中海原型盆地演化

东地中海经历了伸展-聚敛的构造演化旋回,聚集了丰富的油气资源。基于2D地震、ODP Leg160、IHS及Tellus商业数据库和公开发表的文献资料,本文在建立东地中海及周缘构造-地层格架的基础上,恢复了东地中海12个关键地质历史时期的原型盆地,并以板块构造为切入点探讨了盆地演化机制。东地中海及周缘上三叠统以来地层可划分为新特提斯被动大陆边缘陆地及浅水区、新特提斯被动大陆边缘深水区和塞浦路斯弧前褶皱区3个地层分区,前两个地层分区均发育一套裂谷-被动大陆边缘层系,但是二者的岩相特征和不整合发育有明显的差异,而塞浦路斯弧前褶皱区发育一套大洋盆地-弧前盆地层系。研究认为东地中海经历了二叠纪—早侏罗世裂解期、中侏罗世巴柔期—晚白垩世土伦期漂移期和晚白垩世森诺期以来的汇聚改造期3个原型阶段,其中汇聚改造期又可细分为晚白垩世森诺期“双俯冲带”消减期、古近纪北部俯冲-碰撞期、中新世塞浦路斯岛弧带南侧俯冲-碰撞与黎凡特边缘活化期和中新世梅西期以来“弧-山碰撞”与“走滑逃逸”期4个阶段。东地中海盆地演化受控于图哈罗德-安纳托利亚板块以及凯里尼亚、特罗多斯和埃拉托色尼等微板块与冈瓦纳大陆北缘的分离、向北的漂移和与欧亚大陆汇聚拼贴的板块构造活动。     

Low-temperature constraints on the Alpine thermal evolution of the Western Carpathian basement rock complexes

The Cretaceous to Palaeogene Alpine exhumation of previously buried Variscan basements is recorded in the southern portion of the Western Carpathians in the Gemeric and Veporic units. The Meso-Cenozoic collisional processes resulted in basement exhumation of the Tatric Unit from Palaeogene to Neogene times. According to zircon and apatite fission track data, the Gemeric Unit, an uppermost thick-skinned thrust sheet, cooled from depth levels of ∼10 up to 2.5 km (temperature interval of ∼250–60 °C) about 88–64 Ma ago, after the collapse of overlying Meliata-Turňa-Silica Mesozoic accretionary prism. The middle and lower thick-skinned thrust sheets, Veporic and Tatric units, cooled from the depths of ∼10 up to 2.5 km ∼110–40 Ma ago. The process was controlled by unroofing of footwall from beneath the Gemeric Unit. About 50–20 Ma ago, the internal zone of Tatric Unit gradually exhumed to depth of <2 km and some parts of the unit appeared at the surface level. However, the external zone of Tatric Unit was buried beneath the Eocene to Lower Miocene sedimentary successions and exhumed to the subsurface level at ∼21–8 Ma ago, as a result of oblique collision of the Western Carpathians with the European Platform.     

Crustal constraints on the origin of mantle seismicity in the Vrancea Zone, Romania: The case for active continental lithospheric delamination

The Vrancea zone of Romania constitutes one of the most active seismic zones in Europe, where intermediate-depth (70–200 km) earthquakes of magnitude in excess of M_w = 7.0 occur with relative frequency in a geographically restricted area within the 110° bend region of the southeastern Carpathian orogen. Geologically, the Vrancea zone is characterized by (a) a laterally restricted, steeply NW-dipping seismogenic volume (30 × 70 × 200 km), situated beneath (b) thickened continental crust within the highly arcuate bend region of the Carpathian orocline, and (c) miscorrelation of hypocenters with the position of known or inferred suture zones in the Carpathian orogenic system. Geologic data from petroleum exploration in the Eastern Carpathians, published palinspastic reconstructions, and reprocessing of industry seismic data from the Carpathian foreland indicate that (1) crust of continental affinity extends significantly westward beneath the external thrust nappes (Sub-Carpathian, Marginal Folds, and Tarcau) of the Eastern Carpathians, (2) Cretaceous to Miocene strata of continental affinity can be reconstructed westward to a position now occupied by the Transylvanian basin, and (3) geologic structure in the Carpathian foreland (including the Moho) is sub-horizontal directly to the east and above the Vrancea seismogenic zone. Taken together, these geologic relationships imply that the Vrancea zone occupies a region overlain by continental crust and upper mantle, and does not appear to originate from a subducted oceanic slab along the length of the Carpathian orogen. Accordingly, the Vrancea zone appears to potentially be an important place to establish evidence for active lithospheric delamination.     

Erratic shortening from balanced cross-sections of the western Himalayan foreland basin: causes and implications for basin evolution

Balanced cross-sections from the western Himalayan foreland foothill belt reveal a variation in shortening amounts from 22 to 71.3% over a lateral distance of 85 km. The large variation may be attributed to the fact that the method of cross-section balancing considers the initial layering as horizontal, which is an unlikely situation in foreland basins. Simple trigonometric relationships are used to minimize the error in shortening estimates. However, the suggested corrections could not be applied to the Himalayan foreland basin because of unavailability of the required data on initial basin geometry. The study also indicates that shortening rates for the area based on these shortening amounts cannot be used for earthquake prediction.     

东北和华北地区上地幔成分和热状态对比及对中国东部岩石圈减薄的启示

地幔成分与其上覆地壳年龄存在相关关系,年龄越老,地幔越亏损玄武质组分.本文对产于东北和华北地区的尖晶石相橄榄岩包体的成分进行了统计分析,结果显示东北地区橄榄岩包体比华北地区包体更亏损玄武质组分.这说明东北岩石圈地幔比华北上地幔更难熔,但其上覆地壳年龄却远小于华北地区地壳的年龄.这种地壳年龄和地幔组分之间的解耦暗示东北和华北地区的岩石圈地幔形成之后发生了大规模的改造.华北地区的壳幔解耦与中生代岩石圈减薄和增生有关,而东北地区的壳幔解耦则是该区地壳的多期改造和中生代岩石圈减薄和增生等过程综合作用的结果.两地区地幔成分的差异显然与部分熔融程度的不同有关,但影响部分熔融程度的因素很多,目前尚不能确定.包体的平衡温度统计和地温线对比显示东北岩石圈的地温梯度低于华北的地温梯度,可能是东北地区岩石圈减薄的时间要早于华北地区,或者华北岩石圈减薄程度可能大于东北地区的结果,因此中国东部岩石圈减薄存在时空不均一性.     

东海盆地中、新生代盆架结构与构造演化

基于地貌、钻井、岩石测年和地震等资料,分析盆地地层分布、盆架结构、构造单元划分和裂陷迁移规律,结果表明东海盆地由台北坳陷、舟山隆起、浙东坳陷、钓鱼岛隆褶带和冲绳坳陷构成,是以新生代沉积为主、中生代沉积为辅的大型中、新生代叠合含油气盆地;古元古代变质岩系构成了盆地的基底。该盆地不仅是印度-太平洋前后相继的动力体系作用下形成的西太平洋沟-弧-盆构造体系域一部分,而且也是古亚洲洋动力体系作用下形成的古亚洲洋构造域和特提斯洋动力体系作用下形成的特提斯洋构造域一部分,晚侏罗世至早白垩世经历了构造体制转换,盆地格局发生重大变革,早白垩世以前主要受古亚洲-特提斯洋构造体制影响的强烈挤压造山和地壳增厚作用演变为早白垩世以来主要受太平洋构造体制控制的陆缘伸展裂陷和岩石圈减薄作用,经历侏罗纪古亚洲-特提斯构造体制大陆边缘拗陷和白垩纪以来太平洋构造体制弧后裂陷两大演化阶段。白垩纪以来太平洋构造体制的弧后裂陷演化阶段可细分为早白垩世至始新世裂陷期、渐新世至晚中新世拗陷期和中新世末至全新世裂陷期。     

A Late Archean foreland fold and thrust belt in the North China Craton: Implications for early collisional tectonics

The Archean North China craton is divided into the Western and Eastern blocks along the Central Orogenic belt. A 1600 km long Archean foreland basin and thrust belt fringes the eastern side of the Central Orogenic belt. Rocks in the orogen form tectonically-stacked east-vergent fold and thrust sheets including foreland basin sediments, 2.50 Ga ophiolitic mélange, and an island arc complex. Foreland basin sediments overlie a passive margin sequence, and include a 2.50 Ga deep-water turbidite sequence that grades upward and westward into shallow-water molasse, now disposed in structurally imbricated east-verging thrusts and asymmetric folds that gradually migrated craton-ward with deformation, uplift, and erosion of the orogen. There is a strong linked relationship of the formation of the foreland basin to collision of the east and west blocks of the North China craton along the Central Orogenic belt at 2.50 Ga. The Qinglong foreland basin and Central Orogenic belt of the North China craton represents one of the best-preserved Archean orogen-to-craton transitions in the world. Its classic internal to external zonation, and flexural response to loading, demonstrate that convergent tectonics in the Archean were broadly similar to Phanerozoic convergent margin processes.     

Late Cretaceous to early Miocene deposits of the Carpathian foreland basin in southern Moravia

 The Late Cretaceous to Early Miocene strata of the Carpathian foreland basin in southern Moravia (Czech Republic) are represented by a variety of facies which reflects the evolution of the foreland depositional system. However, because of the intensive deformation and tectonic displacement and the lack of diagnostic fossils the stratigraphic correlation and paleogeographic interpretation of these strata are difficult and often controversial. In order to better correlate and to integrate them into a broader Alpine–Carpathian foreland depositional system, these discontinuous and fragmentary strata have been related to four major tectonic and depositional events: (a) formation of the Carpathian foreland basin in Late Cretaceous which followed the subduction of Tethys and subsequent deformation of the Inner Alps-Carpathians; (b) Middle to Late Eocene transgression over the European foreland and the Carpathian fold belt accompanied by deepening of the foreland basin and deposition of organic-rich Menilitic Formation; (c) Late Oligocene to Early Miocene (Egerian) uplifting and deformation of inner zones of the Carpathian flysch belt and deposition of Krosno-type flysch in the foreland basin; and (d) Early Miocene (Eggenburgian) marine transgression and formation of late orogenic and postorogenic molasse-type foreland basin in the foreland. These four principal events and corresponding depositional sequences are recognized throughout the region and can be used as a framework for regional correlation within the Alpine–Carpathian foreland basin. Received: 18 August 1998 / Accepted: 9 June 1999     

鄂尔多斯盆地西缘前陆盆地中生界成岩作用研究

鄂尔多斯西缘前陆盆地中生界储层砂岩成岩作用主要受前陆盆地构造演化的影响,不同构造区带砂岩储层的成岩环境存在一定的差别。研究发现,冲断带近物源区由于杂基和软矿物含量高,压实作用表现较为强烈,砂岩物性较差;但斜坡带远离物源区压实程度较弱,原生粒间孔隙发育。前陆盆地不同区带的构造演化强度不同,形成了不同的成岩强度,冲断带的Ro值为0.5%～0.65%,其成岩演化刚进入晚成岩A期,但成岩演化程度比斜坡带略高,而坳陷带经历的成岩演化最高,成岩演化程度相对较高(Ro:0.7%～0.9%),强度最大。坳陷带比冲断带、斜坡带含有更高含量的富铁方解石,这些铁方解石属于成岩晚期的产物,很难遭受后期溶蚀改造,所以坳陷带中铁方解石含量较高的地区储层物性也比较差,其机理可能与黏土矿物转化和长石类矿物发生溶蚀有关。     

Depositional and structural evolution of a foreland basin margin in a magnetostratigraphic framework: the eastern Swiss Molasse Basin

 This integrated study of the sedimentology, magnetostratigraphic chronology and petrography of the mostly continental clastics of the Oligocene to Miocene Swiss Molasse Basin underpins a reconstruction of facies architecture and delineates relationships between the depositional evolution of a foreland-basin margin and exhumation phases and orogenic events in the adjacent orogen. A biostratigraphically based high-resolution magnetostratigraphy provides a detailed temporal framework and covers nearly the whole stratigraphic record of the Molasse Basin (31.5–13 Ma). Three transverse alluvial fan systems evolved at the southern basin margin. They are characterized by distinct petrographic compositions and document the exhumation and denudation history of the growing eastern Swiss Alps. Enhanced northward propagation of the orogenic wedge is interpreted to have occurred between 31.5 and 26 Ma. During the period 24–19 Ma, intense in-sequence and out-of-sequence thrusting took place as Molasse strata were accreted to the orogenic wedge. A third active tectonic phase, possibly caused by backthrusting of the Plateau Molasse, probably occurred between ca. 15 and 13 Ma. Fan head migration between 31.5 and 13 Ma is probably controlled by the structural evolution of the thrust front due to Molasse accretion and backthrusting. Received: 11 March 1998 / Accepted: 12 March 1999     

东昆仑东段下三叠统洪水川组沉积序列与盆地构造原型恢复

下三叠统洪水川组沉积地层研究结果表明,洪水川组由底到顶可划分为6个岩性段,一段主要为灰绿-肝红色粗碎屑岩及紫红色细碎屑岩组合;二段主要为灰绿色含砾粗砂岩、粗砂岩夹砾岩组合;三段以深灰色-灰黑色薄层-中薄层灰岩为主,四段主要为浅灰色-灰色中-薄层粉砂岩夹灰色薄层灰岩组合,五段主要为鲍马序列中某几段有规律的浊积岩组合,六段主要为灰色中薄层细砾岩、含细砾粗砂岩、细砂岩夹薄层钙质粉砂岩及灰岩组合。岩石组合及沉积结构构造特征表明,洪水川组一段和二段属于扇三角洲沉积体系,三段和四段属于浅海混积陆棚沉积体系,五段属于半深海-深海浊流沉积体系,六段属于滨浅海沉积体系。洪水川组沉积序列与弧前盆地沉积序列相似,记录了一个弧前盆地初始沉积、正常沉积、晚期沉积等连续的沉积-构造演化过程,认为洪水川组是一套形成于阿尼玛卿-布青山古特提斯洋向北俯冲过程中的弧前盆地的产物,客观记录了东昆仑三叠纪弧前盆地形成及古洋壳俯冲过程。     

东昆仑西段晚古生代盆地系

东昆仑西段晚古生代从北向南分别为昆北弧后盆地、昆中岛弧及昆南弧前增生楔.在二叠纪,增生楔又转变成岛弧及弧后盆地.昆北弧后盆地石炭纪发育有陆缘到深海盆地的沉积,二叠纪由碎屑岩过渡为浅海碳酸盐岩.昆中岛弧带沉积盖层为一些碳酸盐岩孤立台地和小的山间盆地,并有火山熔岩、火山碎屑岩的堆积.昆南弧前盆地岩石类型非常复杂,石炭纪包括了陆源碎屑岩、火山熔岩、火岩碎屑岩、钙屑浊积岩、硅质岩等.二叠纪的弧间盆地从深海盆地演化为浅海碳酸盐岩沉积.前锋弧也逐渐露出水面,形成孤立灰岩台地.东昆仑西段晚古生代沉积整体特征具有沉积相分布不对称性及"盆岭"相问展布、沉积类型多样性、物源、古流向的双(多)向性、沉积序列的两层性、沉积物的成熟度低、近源等.盆地演化可划分为盆地扩张阶段、弧陆碰撞阶段两个阶段.总体表现为弧后盆地性质的沉积与演化特点.     

Textural trends in turbidites and slurry beds from the Oligocene flysch of the East Carpathians, Romania

Deep‐water sandstone beds of the Oligocene Fusaru Sandstone and Lower Dysodilic Shale, exposed in the Buz?u Valley area of the East Carpathian flysch belt, Romania, can be described in terms of the standard turbidite divisions. In addition, mud‐rich sand layers are common, both as parts of otherwise ‘normal’ sequences of turbidite divisions and as individual event beds. Eleven units, interpreted as the deposits of individual flows, were densely sampled, and 87 thin sections were point counted for grain size and mud content. S₃/T_a divisions, which form the bulk of most sedimentation units, have low internal textural variability but show subtle vertical trends in grain size. Most commonly, coarse‐tail normal grading is associated with fine‐tail inverse grading. The mean grain size can show inverse grading, normal grading or a lack of grading, but sorting tends to improve upward in most beds. Fine‐tail inverse grading is interpreted as resulting from a decreasing effectiveness of trapping of fines during rapid deposition from a turbidity current as the initially high suspended‐load fallout rate declines. If this effect is strong enough, the mean grain size can show subtle inverse grading as well. Thus, thick inversely graded intervals in deep‐water sands lacking traction structures do not necessarily imply waxing flow velocities. If the suspended‐load fallout rate drops to zero after the deposition of the coarse grain‐size populations, the remaining finer grained flow bypasses and may rework the top of the S₃ division, forming well‐sorted, coarser grained, current‐structured T_t units. Alternatively, the suspended‐load fallout rate may remain high enough to prevent segregation of fines, leading to the deposition of significant amounts of mud along with the sand. Mud content of the sandstones is bimodal: either 3–13% or more than 20%. Two types of mud‐rich sandstones were observed. Coarser grained mud‐rich sandstones occur towards the upper parts of S₃/T_a divisions. These units were deposited as a result of enhanced trapping of mud particles in the rapidly deposited sediment. Finer grained mud‐rich units are interbedded with ripple‐laminated very fine‐grained sandy T_c divisions. During deposition of these units, mud floccules were hydraulically equivalent to the very fine sand‐ and silt‐sized sediment. The mud‐rich sandstones were probably deposited by flows that became transitional between turbidity currents and debris flows during their late‐stage evolution.     

东南极晚新元古—早古生代构造热事件及其在冈瓦纳超大陆重建中的意义

在东南极大陆内部及边缘发育3条晚新元古代—早古生代造山带,即东非造山带（南延部分）、普里兹造山带和罗斯造山带。东非造山带的南延部分主要出露于吕措—霍尔姆湾—毛德王后地—沙克尔顿岭地区,其内发育蛇绿岩、榴辉岩相超镁铁岩及逆冲—推覆构造,因而被解释为东、西冈瓦纳陆块拼合的缝合线。罗斯造山带主要出露于横贯南极山脉地区,其内保存有大陆裂解、洋壳俯冲和地体增生的地质纪录,代表冈瓦纳超大陆的活动大陆边缘。普里兹造山带主要出露于普里兹湾和登曼冰川,因其位于从前假设的统一东冈瓦纳陆块的内部,加之缺少蛇绿混杂岩、岛弧增生杂岩和高压变质岩（如蓝片岩或榴辉岩）等与大洋板块俯冲作用密切相关的岩石,所以当前存在着碰撞造山成因和板内改造成因两种不同的认识。普里兹造山带构造性质的确定不仅决定了冈瓦纳超大陆的汇聚过程和方式,也制约了罗迪尼亚超大陆的形成和演化过程。因此,开展普里兹造山带的研究对于揭示新元古代—早古生代的全球构造演化具有重要的科学意义。     

阿曼山西侧前陆区构造演化特征及地质意义

阿曼山北部西侧前陆区勘探程度很低,目前的构造单元划分弱化了其重要性,深化区域构造地质特征及演化过程具有重要科学意义。依据区域最新的重力及井震资料,以构造地质建模理论为指导并结合生长地层分析及平衡剖面方法,开展对区域的构造演化分析。研究认为阿曼山北部西侧前陆区以收缩构造为主,具有完整的前陆盆地结构。生长地层特征显示区域发育两期快速隆升时期,晚白垩世区域开始进入前陆演化阶段,构造结构定型于中新世。Fiqa组泥岩作为区域重要的滑脱层,对区域的变形起到了重要作用。通过剖面复原技术可以将区域演化划分为3大时期4个阶段,中、新生代区域长时间处于被动陆缘演化阶段,发育多旋回大套的碳酸盐岩,生储盖空间配置良好,具有较大勘探潜力。     

Petrogenesis of massif-type anorthosite complex, Gruber, Central Dronning Maud Land, East Antarctica： Implications for magma source and evolution

The origin of anorthosite and associated igneous gabbronorite and ferrodiorite was investigated through detailed study of a typical massif-type anorthosite complex from Gruber, Central Dronning Maud Land, East Antarctica. Field observations showed that the Gruber Complex is made up of gabbronorite-anorthosite pluton which was intruded by ferrodiorite dykes. Systematic samples collected from the Gruber Complex revealed significant geochemical variations within the region. Four rock types have been identified, based on modal proportions of mineral phases and their geochemistry data. Clinopyroxene-gabbronorite and plagioclase-gabbronorite are the two types of gabbronorite with the dominance of clinopyroxene and plagioclase, respectively. Anorthosite is represented by rocks having predominance of plagioclase with minor clinopyroxene. Ferrodiorite is characterized by modal abundance of orthopyroxene and Fe-Ti oxide. Major and trace element systematics showed that all the four rock types are co-magmatic and are related through fractional crystallization. Based on this study, it is reported that clinopyroxene was the first phase to crystallize followed by plagioclase and then Fe-Ti oxides. Furthermore, trace element composition of the parental melt was calculated using LA-ICPMS analysis of the most primitive, pure clinopyroxene found in the clinopyroxene gabbronorite. Our analyses suggested that the parental melt was similar to that of continental arc basalt and showed signatures of subduction-related metasomatism. Based on mineral chemical and geochemical data, it is interpreted that the parent melt went through changing sequence of crystallization which led to the formation of massive anorthosite.     

Identification of an underfilled foreland basin system in the Upper Devonian of the Central Pyrenees: implications for the Hercynian orogeny

A foreland basin succession has been identified in the Frasnian of the Central Pyrenees. This succession comprises a carbonate-dominated transgressive system which recorded the cratonward migration of the foreland basin subsidence, and siliciclastic depocenters which recorded the progression of the thrust-fold deformation. The foreland basin system has always been maintained in deep-marine environments, i.e., at an underfilled depositional state. It was associated with a thrust wedge which descended toward a deep-marine hinterland, i.e., with a type of orogenic wedge usually related to subduction zones. The Frasnian foreland basin system differs from the one known in the Carboniferous which evolved to overfilled depositional state and was associated with a thrust wedge rising toward a mountainous hinterland. Consequently, the Hercynian orogeny in the Pyrenees seems to result first, from a Frasnian thrusting controlled by a subduction zone located north of the Pyrenees, and second, from a Carboniferous thrusting controlled by the surrection of a frontal thrust belt in the Pyrenees. The association of underfilled foreland basin systems and hinterland-dipping thrust wedges, as exemplified in the Frasnian of the Pyrenees, can be interpreted as illustrative of the initial stages of thrust-wedge growth in deep-marine settings.     

东太平洋海盆CC区沉积物因子分析揭示的沉积环境地球化学演化信息

对中国大洋矿产资源开发研究协会DY851和DY853航次获得的东太平洋晚新生代沉积物(包括61个表层沉积物样品和16个沉积物柱状岩芯)进行了系统的地球化学和数理统计分析，揭示了东太平洋海盆CC区晚新生代沉积环境地球化学演化的一些特征。认为洋底扩张、沉积区离东太平洋洋脊的距离、海底的地热强度及地热活动频率影响了研究区CCD的深度和CCD波动的频率及幅度，从而在一定程度上制约了研究区的沉积环境。     

冈底斯-喜马拉雅碰撞造山带前陆盆地系统及构造演化

碰撞带前陆盆地的建立是大陆碰撞的直接标志和随后造山带构造变形的忠实记录。本文对欧亚板块与印度板块碰撞前后发育在拉萨地块上的冈底斯弧背前陆盆地,同碰撞产生的雅鲁藏布江周缘前陆盆地,以及碰撞后陆内变形产生的喜马拉雅前陆盆地的沉积地层演化以及碎屑锆石物源特征等进行了系统分析,结合前人及我们近些年的研究成果,认为冈底斯岛弧北侧发育一个典型的弧背前陆盆地系统而不是以前普遍接受的伸展盆地。除传统认为的喜马拉雅前陆盆地系统外,在碰撞造山带中还发育一个雅鲁藏布江前陆盆地系统,它是欧亚板块与印度板块碰撞以后,欧亚板块加载到印度被动大陆边缘产生的典型周缘前陆盆地。上述2个造山带前陆盆地系统的识别,大大提高了对新特提斯洋俯冲、碰撞过程的认识。造山带前陆盆地证据指示,新特提斯洋至少于140 Ma以前就已开始俯冲, 110 Ma俯冲速度开始提高,在65 Ma前后印度大陆与欧亚大陆发生碰撞,喜马拉雅山于40 Ma开始隆升,其剥蚀物质大量堆积在喜马拉雅前陆盆地中。