150 Million year history of North China Craton disruption preserved in Mesozoic sediments of the Ordos basin

ABSTRACT

The Ordos Basin, situated in the western part of the North China Craton, preserves the 150-million-year history of North China Craton disruption. Those sedimentary sources from Late Triassic to early Middle Jurassic are controlled by the southern Qinling orogenic belt and northern Yinshan orogenic belt. The Middle and Late Jurassic deposits are received from south, north, east, and west of the Ordos Basin. The Cretaceous deposits are composed of aeolian deposits, probably derived from the plateau to the east. The Ordos Basin records four stages of volcanism in the Mesozoic–Late Triassic (230–220 Ma), Early Jurassic (176 Ma), Middle Jurassic (161 Ma), and Early Cretaceous (132 Ma). Late Triassic and Early Jurassic tuff develop in the southern part of the Ordos Basin, Middle Jurassic in the northeastern part, while Early Cretaceous volcanic rocks have a banding distribution along the eastern part. Mesozoic tectonic evolution can be divided into five stages according to sedimentary and volcanic records: Late Triassic extension in a N–S direction (230–220 Ma), Late Triassic compression in a N–S direction (220–210 Ma), Late Triassic–Early Jurassic–Middle Jurassic extension in a N–S direction (210–168 Ma), Late Jurassic–Early Cretaceous compression in both N–S and E–W directions (168–136 Ma), and Early Cretaceous extension in a NE–SW direction (136–132 Ma).     

Cretaceous sedimentary basins in Sichuan,SW China: Restoration of tectonic and depositional environments

This study documents sediment infill features and their responses to the tectonic evolution of the Sichuan Basin and adjacent areas. The data include a comparison of field outcrops, well drillings, inter-well correlations, seismic data, isopach maps, and the spatial evolution of sedimentary facies. We divided the evolutionary history of the Sichuan Cretaceous Basin into three stages based on the following tectonic subsidence curves: the early Early Cretaceous (145–125 Ma), late Early Cretaceous to early Late Cretaceous (125–89.8 Ma), and late Late Cretaceous (89.8–66 Ma). The basin underwent NW–SE compression with northwestward shortening in the early Early Cretaceous and was dominated by alluvial fans and fluviolacustrine sedimentary systems. The central and northern areas of the Sichuan Basin were rapidly uplifted during the late Early Cretaceous to early Late Cretaceous with southwestward tilting, which resulted in the formation of a depression, exhibited southwestward compression, and was characterized by aeolian desert and fluviolacustrine deposits. The tectonic framework is controlled by the inherited basement structure and the formation of NE mountains, which not only affected the clastic supply of the sedimentary basin but also blocked warm-wet currents from the southeast, which changed the climatic conditions in the late Late Cretaceous. The formation and evolution of Cretaceous sedimentary basins are closely related to synchronous subtle far-field tectonism and changes in climate and drainage systems. According to the analysis of the migration of the Cretaceous sedimentation centers, different basin structures formed during different periods, including periods of peripheral mountain asynchronous thrusting and regional differential uplift. Thus, the Sichuan Cretaceous sedimentary basin is recognized as a superimposed foreland basin.     

楚雄中生代前陆盆地的构造沉降史研究

云南楚雄盆地位于场子陆块的西南边缘,为一典型的中生代周缘前陆盆地,盆地演化阶段明显,晚三叠世为前陆早期复理石沉积,侏罗纪则为前陆晚期磨拉石沉积。对盆地构造沉降史研究后笔者认为：①晚三叠世复理石沉积盆地构造沉降幅度巨大,沉降与沉积中心位于盆地最西部,紧邻古哀牢山造山带,沉积体呈形楔形展布;③侏罗纪磨拉石沉积盆地构造沉降和沉积中心以及前缘隆起向内陆方向迁移明显;③中生代构造快速沉降的沉积体的楔形展布表     

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.     

西藏羌塘盆地中生代晚期构造事件与油气的关系

羌塘盆地在中生代晚期发生一次重要的构造运动,导致盆地结束海相沉积历史并形成区域性不整合。对该期构造事件发生的时代以及其对盆地油气成藏与保存的影响一直存在争议。本文根据近年来对羌塘盆地地层时代的新认识,结合盆地沉积埋藏和油气生成过程分析,认为该构造事件主要发生于早-晚白垩世之间(~100Ma),为班公湖-怒江洋盆最终闭合和拉萨-羌塘地块碰撞的结果。构造事件与盆地主要烃源岩该的生烃同时,盆地内与构造事件有关的圈闭构造为油气成藏提供了良好的场所,是盆地的主要评价和勘探目标。     

珠江口盆地深水区晚中新世以来构造沉降与似海底反射（BSR）分布的关系*

2007年中国在南海北部神狐海域通过钻探首次获得天然气水合物样品,证实了珠江口盆地深水区是水合物富集区。通过对珠江口盆地深水区构造沉降史的定量模拟研究,发现晚中新世以来区内构造沉降总体上具有由北向南、自西向东逐渐变快的演化趋势;从晚中新世到更新世,盆地深水区经历了构造沉降作用由弱到强的变化过程：晚中新世(11.6～5.3 Ma),平均构造沉降速率为67 m/Ma;上新世(5.3～1.8 Ma),平均构造沉降速率为68 m/Ma;至更新世(1.8～0 Ma),平均构造沉降速率为73 m/Ma。而造成这些变化的主因是发生在中中新世末-晚中新世末的东沙运动和发生在上新世-更新世早期的台湾运动。东沙运动（10～5 Ma）使盆地在升降过程中发生块断升降,隆起剥蚀,自东向西运动强度和构造变形逐渐减弱,使得盆地深水区持续稳定沉降;台湾运动（3 Ma）彻底改变了盆地深水区的构造格局,因重力均衡调整盆地深水区继续沉降,越往南沉降越大。将似海底反射（BSR）发育区与沉降速率平面图进行叠合分析,发现80％以上的BSR分布趋于构造沉降速率值主要在75～125 m/Ma之间、沉降速率变化迅速的隆坳接合带区域。     

鄂尔多斯盆地中新生代峰值年龄事件及其沉积-构造响应

通过锆石-磷灰石裂变径迹年龄分布及其与粗碎屑沉积建造和地层不整合关系的综合分析,提供了鄂尔多斯盆地中新生代构造事件的年代学约束及其沉积响应特点。印支期构造事件主要发生在230～190Ma,包含215Ma和195Ma两个峰值年龄,在盆地西南缘发育晚三叠世粗碎屑类磨拉石建造及其与上覆地层的平行不整合。燕山期构造事件主要发生在燕山中晚期的150～85Ma,包含145Ma、120Ma和95Ma等3个峰值年龄,在盆地西南缘发育燕山中期的晚侏罗世和早白垩世的粗碎屑类磨拉石建造及其地层间的角度不整合。喜山期构造事件主要表现为盆地区域的多旋回构造隆升,至少包含55Ma、25Ma和5Ma等3个幕次的峰值年龄事件。其中,锆石和磷灰石叠合分布的峰值年龄(145Ma)和其相关的角度不整合、逆冲推覆和区域岩浆活动等,共同指示了鄂尔多斯盆地中新生代的一次关键构造变革事件。     

Thermal History since the Paleozoic in the Eastern Qaidam Basin,Northwest China

The Qaidam Basin is the one of the three major petroliferous basins in northeastern Tibetan Plateau, which has experienced multiphase superimposition and transformation. The study of thermal history not only plays an important role on revealing the tectonic origin of the Qaidam Basin and the forming mechanism and uplift history of the Tibetan Plateau,but also can provide scientific evidence for the assessment of oil and gas resources. This work used balanced cross-section technique and apatite fission track ages with modeling of fission track length distribution to infer that the eastern Qaidam Basin has experienced significant tectonic movement in the Early Jurassic movement(～200 Ma), which caused the carboniferous uplift and denudation, the geological movement in the Late Cretaceous, characterized by early stretching and late northeast-southwest extrusion; the Himalayan movement in multi-stage development in eastern Qaidam Basin, which can be divided into the early Himalayan movement(41.1–33.6 Ma) and the late Himalayan movement(9.6–7.1 Ma, 2.9–1.8 Ma), and large-scale orogeny caused pre-existing faults reactivated in late Himalayan movement. On the basis of burial history reconstruction, the thermal history of eastern Qaidam Basin was restored. The result shows that the thermal history in eastern Qaidam Basin shows slow cooling characteristics; the paleo-geothermal gradient of eastern Qaidam Basin was 38–41.5℃/km, with an average value of 39.0℃/km in the Late Paleozoic, 29–35.2℃/km, with an average value of 33.0℃/km in the Early Paleogene; the geothermal gradient of the Qaidam Basin increased in the Late Paleogene, which was similar to the present geothermal gradient in the Late Neogene. The characteristics of the tectono-thermal evolution since Paleozoic in the eastern Qaidam Basin are mainly controlled by magmatic thermal events in the study area.     

鄂尔多斯盆地东南南召地区中生代以来的构造演化研究——来自低温热年代学的证据

有关鄂尔多斯三叠纪原型盆地的东南向展布情况不是非常明确,之前有研究表明其东南缘可能位于南召地区,对该区构造演化过程开展研究,可为鄂尔多斯三叠纪原型盆地研究提供重要信息。因此,为了研究南召地区中生代以来的构造演化史及其与鄂尔多斯盆地之间的关系,本文对研究区3条野外剖面上3件三叠系样品开展锆石、磷灰石裂变径迹研究。其锆石裂变径迹年龄为270±15~181±8Ma,与地层年龄相近或大于地层年龄,不能很好地反映地层经历的构造改造时限,可能更多地代表了物源区的信息。磷灰石裂变径迹年龄为57±3~47±5Ma,结合裂变径迹年龄和热史模拟,本文认为南召地区自三叠纪以来经历了4期较大规模的构造改造,早期是三叠纪末遭受了秦岭造山带强烈逆冲推覆对本区的影响;中期是中晚侏罗世到晚白垩世初;晚期是晚白垩世;末期是喜马拉雅期,4期构造改造均与秦岭造山带的构造演化息息相关。此外,通过与鄂尔多斯盆地周缘地区展开对比,发现二者构造演化过程具有相似的时限性,从构造演化的角度支持南召地区属于鄂尔多斯原型盆地的观点。     

银川盆地构造反转及其演化与叠合关系分析

以银川盆地构造反转为研究对象,从构造反转证据、反转时期以及反转强度等方面进行了分析,以此为基础,探讨 了银川盆地中生代以来构造演化。研究表明:负反转构造的发育、新生界与中-古生界地层展布特征的差异性以及伸展构 造样式与挤压构造样式并存等方面证明银川盆地发生负反转;构造反转的挤压隆升时期为晚侏罗世,伸展沉降期为渐新世 至新近纪;银川盆地北部构造反转强度大于南部,西部反转强度大东部;银川盆地自中生代以来经历了三叠纪至早-中侏 罗世时期的整体沉降、晚侏罗世的挤压隆升与差异剥蚀、早白垩世的再次沉降、白垩纪末期至新生代早期的整体隆升剥 蚀、渐新世至新近纪的快速断陷以及第四纪的整体拗陷六个演化叠合阶段。     

Geology of the 2018 Winter Olympic site,Pyeongchang, Korea

We review the geology of the Gyeonggi Massif, Gyeonggi Marginal Belt, and Taebaeksan Basin of the Korean Peninsula, which are relevant to the 2018 Winter Olympic sites. Neoarchaean–Palaeoproterozoic gneisses and schists of the Gyeonggi Massif underwent two distinct collisional orogenies at the Palaeoproterozoic (1.88–1.85 Ga) and Triassic (245–230 Ma). These basement rocks are structurally overlain by a suite of Mesoproterozoic to Early Permian supracrustal rocks of the Gyeonggi Marginal Belt, consisting primarily of medium-pressure schists and amphibolites metamorphosed at ~270–250 Ma. In contrast, sedimentary successions in the Taebaeksan Basin, commonly fossiliferous, consist primarily of Early Cambrian–Middle Ordovician Joseon Supergroup and Late Carboniferous–Early Triassic Pyeongan Supergroup. The ‘Great Hiatus’ between the two supergroups is characteristic for the North China Craton. The marked contrast in tectonometamorphic evolution between the Taebaeksan Basin and Gyeonggi Marginal Belt suggests an existence of major suture in-between, which is most likely produced by the Permian–Triassic continental collision between the North and South China cratons. Finally, recent tectonics of the Korean Peninsula is governed by the opening of East Sea/Sea of Japan during the Late Oligocene–Early Miocene. This back-arc rifting event has resulted in an exhumation of the Taebaek Mountain Range, estimated to be 22 ± 3 Ma on the basis of apatite (U–Th)/He ages. Thus, high topography in the 2018 Winter Olympic sites is the consequence of Tertiary tectonics associated with the opening of a back-arc basin.     

Mesozoic to Cenozoic retroarc basin evolution during changes in tectonic regime,southern Central Andes (31–33°S): Insights from zircon U-Pb geochronology

The southern Central Andes of Argentina and Chile (27–40°S) are the product of deformation, arc magmatism, and basin evolution above a long-lived subduction system. With sufficient timing and provenance constraints, Andean stratigraphic and structural records enable delineation of Mesozoic-Cenozoic variations in subsidence and tectonic regime. For the La Ramada Basin in the High Andes at ∼31–33°S, new assessments of provenance and depositional age provided by detrital zircon U-Pb geochronology help resolve deformational patterns and subsidence mechanisms over the past ∼200 Myr. Marine and nonmarine clastic deposits recorded the unroofing of basin margins and sediment contributions from the Andean magmatic arc during Late Triassic to Early Cretaceous extension, thermal subsidence, and possible slab rollback. Subsequent sediment delivery from the Coastal Cordillera corresponded with initial flexural accommodation in the La Ramada Basin during Andean shortening of late Early Cretaceous to Late Cretaceous age. The architecture of the foreland basin was influenced by the distribution of precursor extensional depocenters, suggesting that inherited basin geometries provided important controls on later flexural subsidence and basin evolution. Following latest Cretaceous to early Paleogene tectonic quiescence and a depositional hiatus, newly dated deposits in the western La Ramada Basin provide evidence for a late Paleogene episode of intra-arc and proximal retroarc extension (development of the Abanico Basin, principally in Chile, at ∼28–44°S). Inversion of this late Paleogene extensional basin system during Neogene compression indicates the southern Central Andes were produced by at least two punctuated episodes of shortening and uplift of Late Cretaceous and Neogene age.     

鄂尔多斯盆地构造沉降特征及对盆地成因的启示

构造沉降作为盆地成因研究中的重要组成部分,对其特征进行分析有助于盆地成因的解析。本次通过对鄂尔多斯盆地内5口典型探井的多期不整合所代表的的剥蚀厚度进行恢复,结合去压实矫正模型以及平均密度、平均古水深等参数的确定,较为精确地刻画出了鄂尔多斯盆地不同构造单元自早寒武世至今的构造沉降特征,同时结合裂谷盆地瞬时拉张模型、裂后热坳陷模型以及前陆盆地挠曲模型对构造沉降曲线进行了模拟,对盆地成因进行分析。鄂尔多斯盆地中寒武世—中生代末期主要由早古生代沉降旋回、二叠—三叠纪沉降旋回与侏罗—白垩纪沉降旋回组成。其中岩石圈热冷却作用引起的沉降贯穿全地质时期。早古生代沉降旋回中,中寒武世的加速沉降主要体现在盆地南部,沉降机制为岩石圈伸展减薄,中奥陶世马家期为全盆地尺度的加速沉降,沉降机制仍为岩石圈伸展减薄。二叠—三叠纪沉降旋回中,晚二叠世—早-中三叠世为该旋回的加速沉降期,该期加速沉降具有多幕裂陷的特征。侏罗—白垩纪沉降旋回中,中侏罗世盆地南部处于缓慢沉降期,沉降机制为岩石圈热冷却作用,晚侏罗世—早白垩世,除伊盟隆起,盆地整体处于加速沉降期,沉降机制为前陆盆地引起的挠曲沉降。     

Sedimentation rate and subsidence history of the southeastern Karoo Basin,South Africa,using 1D backstripping method

Backstripping analysis has been carried out on five boreholes and one outcrop section of the Ecca Group in the Main Karoo Basin of South Africa to determine the sedimentation rate and subsidence history of the basin. The result shows that the rate of sedimentation in the Prince Albert, Whitehill, Collingham, Ripon and Fort Brown Formations range between 0.003–0.03, 0.02–0.05, 0.01–0.05, 0.03–0.22, and 0.15–0.025 mm year^?1, respectively. The backstripped subsidence curves that are constructed by removing the effects of decompaction to the water column and sediment loads show subsidence rates decreasing with time, resembling the typical thermal subsidence curves of passive continental margins. Three major subsidence episodes characterized the Ecca Group, namely, (1) rapid subsidence in an extensional regime, (2) slow subsidence in the middle of basin development and (3) another rapid subsidence in a compressional regime. The aforementioned subsidence episodes show that the southeastern Karoo Basin was located on a passive continental margin, suggesting that the subsidence was initiated and mainly controlled by mechanical (gravitational loading) or tectonic events, with little contribution of thermal events. The average rate of tectonic subsidence in the Prince Albert, Whitehill, Collingham, Ripon and Fort Brown Formations are 63, 28, 25, 215 and 180 m Ma^?1, respectively. It is also inferred that the southeastern Karoo Basin evolved from a passive continental margin into an Andean-type continental foreland basin; thus, portraying a completely evolved post-rift setting along the southeastern Gondwana margin.     

藏高珠穆朗玛峰地区三叠系层序地层及沉积演化：—从陆表海盆地到裂谷盆地

珠峰地区的三叠系形成于大陆拉伸背景。自下而上可划分为12个三级沉积层序和5个层序组，分属于2个中层序。发生在Induan阶初期（约250Ma)，Anisian阶早期（约239Ma),Carnian阶初期（约231Ma）和Norian早期（约223Ma)的4个海侵事件最为重要。可作跨越板块的地层对比标志。藏南地区在三叠纪经历了从泛大陆到大陆裂谷的构造演化，早一中三叠世以陆表海盆地浅水环境为主，晚三叠世以深水断陷盆地为特征。晚三叠世晚期，与长期全球海平面下降相伴随，过量的陆源碎屑输入造成该地区由深水盆地转为河流作用明显的三角洲平原环境。     

Meso-Cenozoic tectonic evolution of the Dangyang Basin,north-central Yangtze craton,central China

Based on detailed structural data and available tectonic chronological data from the Dangyang Basin, the authors propose that the north-central Yangtze craton experienced three stages of tectonic evolution since Late Triassic time. In the Late Triassic to Early Jurassic (T₃–J₁), due to the Indosinian orogeny, nearly N–S compression and shortening occurred, which initiated the Dangyang Basin as a foreland basin of the Qinling–Dabie orogen. During the Late Jurassic–Early Cretaceous (J₃–K₁) period, the Yanshanian intracontinental orogeny caused contemporaneous NE–SW and NW–SE shortening, which resulted in intense folding of the foreland basin; contraction formed a brush structure diverging in a SE direction and strongly converging in a NW direction around the Huangling anticline. In the Late Cretaceous to Palaeogene, the Yuan'an and Hanshui grabens were separated from other parts of the Dangyang Basin due to post-orogenic ENE–WSW extension. Finally, at the end of the Palaeogene, ENE–WSW shortening led to inversion and deformation of the grabens.     

Exhumation History of the Xining Basin Since the Mesozoic and Its Tectonic Significance

The Xining Basin is located in the northeastern Qinghai–Tibetan Plateau, and its continuous Cenozoic strata record the entire uplift and outgrowth history of the Tibetan Plateau during the Cenozoic. The newly obtained apatite fission track data presented here shows that the Xining Basin and two marginal mountain ranges have experienced multiphase rapid cooling since the Jurassic, as follows. In the Middle–Late Jurassic, the rapid exhumation of the former Xining Basin resulted from collision between the Qiangtang Block and the Tarim Block. During the Early–Late Cretaceous, the former Xining Basin underwent a tectonic event due to marginal compression, causing the angular unconformity between the Upper and Lower Cretaceous. In the Late Cretaceous to the Early Cenozoic, collision between the Qiangtang Block and the Lhasa Block may have resulted in the rapid exhumation of the Xining Basin and the Lajishan to the south. In the Early Cenozoic(ca. 50–30 Ma), collision between the Indian and Eurasia plates affected the region that corresponds to the present northeastern Qinghai–Tibetan Plateau. During this period, the central Qilian Block rotated clockwise by approximately 24° to form a wedge-shaped basin(i.e., the Xining Basin) opening to the west. During ca. 17–8 Ma, the entire northeastern Qinghai–Tibetan Plateau underwent dramatic deformation, and the Lajishan uplifted rapidly owing to the northward compression of the Guide Basin from the south. A marked change in subsidence occurred in the Xining Basin during this period, when the basin was tectonically inverted.     

Seismic reflection evidence for the evolution of the Camden Syncline and Lapstone Structural Complex,central Sydney Basin,Australia

The Camden Syncline and the Lapstone Structual Complex are two major geological features of the central Sydney Basin. We have interpreted over 500 km (45 lines) of an unpublished recenty reprocessed seismic dataset as a means to elucidating the evolution of both features. Major horizons observed in the seismic data have been described and correlated with significant tectonic events that shaped the formation of the greater Sydney–Gunnedah–Bowen Basin; namely Early Permian extension, mid-Permian passive thermal subsidence and Late Permian to mid-Triassic foreland loading. Horizon mapping shows that the Camden Syncline is a broad north-northeast plunging structure whose western limb is truncated by the north–south trending faults and folds of the Lapstone Structural Complex. Furthermore, isochron maps reveal that the Late Permian to mid-Triassic sedimentary succession thickens towards the axis of the Camden Syncline, thus confirming it's role as a depocentre during this period of basin evolution. No abrupt thickening is observed in the Late Permian to mid-Triassic sedimentary succession in the vicinity of the Lapstone Structural Complex indicating that the Lapstone Structural Complex was formed subsequent to the deposition of the Permian–Triassic Sydney Basin sedimentary succession. Furthermore, our interpretation of the reprocessed seismic data confirms that the major structural style of the Lapstone Structural Complex is that of west dipping reverse faults and east facing monoclines.     

The thermo-tectonic history of the Song-Kul plateau, Kyrgyz Tien Shan: Constraints by apatite and titanite thermochronometry and zircon U/Pb dating

The Song-Kul Basin sits on a plateau at the Northern and Middle Kyrgyz Tien Shan junction. It is a lacustrine basin, occupied by Lake Song-Kul and predominantly developed on igneous basement. This basement was targeted for a multi-method chronological study to identify the different magmatic episodes responsible for basement formation and to constrain the timing of the development of its present-day morphology. Zircon U/Pb dating by LA-ICP-MS revealed four different magmatic episodes: a Late Cambrian (~ 500 Ma) island arc system, a Late Ordovician (~ 450 Ma) subduction related intrusion, an Early Permian (~ 290 Ma) collisional stage, and a Middle to Late Permian (~ 260 Ma) post-collisional magmatic pulse. Middle to Late Triassic (~ 200–230 Ma) titanite fission-track ages and Late Triassic – Early Jurassic (~ 180–210 Ma) apatite fission-track ages and thermal history modeling indicate the Song-Kul basement was already emplaced in the shallow crust at that time. An exhumed fossil apatite fission-track partial annealing zone is recognized in the bordering Song-Kul mountain ranges. The area experienced only minor post-Early Mesozoic denudation. The igneous basement was slowly brought to apatite (U–Th)/He retention temperatures in the Late Cretaceous–Palaeogene. Miocene to present reactivation of the Tien Shan does not manifestly affect this part of the orogen.     

川西南甘洛地区中—新生代构造沉降史分析及对铅锌保存的约束

本文通过碎屑岩磷灰石、锆石裂变径迹和炭质泥岩镜质体反射率相结合的办法,重建了甘洛地区中—新生代的构造沉降史,进而探讨了构造沉降史对铅锌保存状态的约束。研究表明:晚三叠世,甘孜-理塘洋盆和西秦岭地区洋盆的闭合作用导致研究区变为前陆环境,并开始迅速接受陆相沉积,埋深迅速增加,增幅达7.6km;晚三叠世至古近纪,甘洛地区经历过多次抬升-沉降作用,总体表现为缓慢抬升,平均抬升速率不高于32.7m/Ma;新近纪,甘洛地区快速差异隆升北部抬升速率高于南部,25.5~10.3Ma期间,平均抬升速度超过295m/Ma;在6Ma至今,平均抬升速率超过667m/Ma。快速隆升过程早于川南马边地区和临沧地区,而明显晚于攀西地区,这在一定程度上支持了青藏高原东部边界晚新生代以来幕式抬升及分步向外扩展的观点。构造沉降史结果表明成矿后的深埋藏作用对原生铅锌矿具有重要的保存作用,并影响到现今矿体的就位深度。