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1.
洋壳厚度受多方面因素的影响，前人大多关注地幔温度、地幔源成分等岩石圈深部因素，很少关注岩石圈浅层的热液循环对洋壳厚度的影响。利用基于有限元的数值模拟手段，对扩张期不同背景(洋中脊、拆离断层)、不同扩张速率的热液循环与洋壳增生的关系进行研究。结果表明：洋壳增生达到稳定前，热液循环导致理论洋壳厚度发生阶段性减薄，减薄量随时间改变，并且推迟了上地幔中熔融体出现的时间；当洋壳增生达到稳定后，热液循环下产生的理论洋壳厚度反而比无热液循环的更厚。结合洋壳增生过程中对流热通量的变化分析，在洋壳增生前期的上地幔温度低，驱动热液循环的热源小，产生的对流热通量相对较小且不稳定，热液循环缓慢冷却上地幔顶部的温度，进而推迟上地幔初始熔融的时间，减弱上地幔的熔融，并造成一定时间阶段内的生成理论洋壳比正常理论洋壳厚度更薄；当洋壳增生达到稳定后，对流热通量达到最大并稳定，热液循环持续快速的冷却上地幔顶部温度，导致上地幔深部的热向上地幔顶部补给，反而增大了上地幔顶部的温度和熔融量，进而增大了理论洋壳厚度。随着扩张速率的增大，理论洋壳厚度增大，对流热通量增大，热液循环导致的洋壳阶段性减薄的最大减薄量也增大，阶段性减薄的时间缩短。结合南海西南次海盆的洋壳结构特征分析：两条横跨南海西南次海盆的地震剖面显示，海盆内存在异常薄的洋壳区域，并且两条地震剖面的最薄洋壳厚度相差0. 85 km,推测海盆内异常薄洋壳和不同扩张时期的最薄洋壳厚度差异受到扩张期热液循环阶段性减薄洋壳作用的影响。 相似文献
2.
Carbonate environments inhabit the realm of the surface, intermediate and deep currents of the ocean circulation where they produce and continuously deliver material which is potentially deposited into contourite drifts. In the tropical realm, fine‐grained particles produced in shallow water and transported off‐bank by tidal, wind‐driven, and cascading density currents are a major source for transport and deposition by currents. Sediment production is especially high during interglacial times when sea level is high and is greatly reduced during glacial times of sea‐level lowstands. Reduced sedimentation on carbonate contourite drifts leads to early marine cementation and hardened surfaces, which are often reworked when current strength increases. As a result, reworked lithoclasts are a common component in carbonate drifts. In areas of temperate and cool water carbonates, currents are able to flow across carbonate producing areas and incorporate sediment directly to the current. The entrained skeletal carbonate particles have variable bulk density and shapes that lower the prediction of transport rates in energy‐based transport models, as well as prediction of current velocity based on grain size. All types of contourite drifts known in clastic environments are found in carbonate environments, but three additional drift types occur in carbonates because of local sources and current flow diversion in the complicated topography inherent to carbonate systems. The periplatform drift is a carbonate‐specific plastered drift that is nearly exclusively made of periplatform ooze. Its geometry is built by the interaction of along‐slope currents and downslope currents, which deliver sediment from the adjacent shallow‐water carbonate realm to the contour current via a line source. Because the periplatform drift is plastered on the slopes of the platforms it is also subject to mass gravity flow and large slope failures. At platform edges, a special type of patch drift develops. These hemiconal platform‐edge drifts also contain exclusively periplatform ooze but their geometry is controlled by the current around the corner of the platform. At the north‐western end of Little and Great Bahama Bank are platform‐edge drifts that are over 100 km long and up to 600 m thick. A special type of channel‐related drift forms when passages between carbonate buildups or channels within a platform open into deeper water. A current flowing in these channels will entrain material shed from the sediment producing areas. At the channel mouth, the sediment‐charged current deposits its sediment load into the deeper basin. With continuous flow, a submarine delta drift is built that progrades into the deep water. The strongly focused current forming the delta drift, is able to rework coarse skeletal grains and clasts, making this type of carbonate drift the coarsest drift type. 相似文献
3.
V. V. Zuev V. A. Semenov E. A. Shelekhova S. K. Gulev P. Koltermann 《Doklady Earth Sciences》2012,445(2):1006-1010
In this work, we evaluate the impact of terminated oceanic heat flux in the North Atlantic and Barents Sea on the Northern Hemisphere climate in January by numerical experiments with a coupled model of atmospheric general circulation and a thermodynamic model of the upper mixed layer of the ocean. We analyze the variations in the atmospheric circulation and near-surface temperature. We found that the termi-nation of the oceanic heat flux leads to a depression in atmospheric centers of action in the Northern Hemi-sphere (by 3?C5 hPa) and a significant cooling over the continents with the strongest temperature decrease down to ?10°C in northwestern Eurasia. 相似文献
4.
在系统分析淮南煤田大量地面钻孔井温测井数据和井下巷道围岩温度测试数据的基础上,结合58块岩石样品的热导率测试结果,全面阐述了该区现今地温梯度和大地热流的分布特征。研究表明,淮南煤田现今地温梯度的众值介于2.50~3.50℃/hm之间,平均地温梯度为2.9℃/hm;大地热流值变化范围为31.87~83.9 m W/m2,平均热流值为63.69 m W/m2,地温梯度和热流值区均高于淮北煤田;大地热流受地温梯度控制明显,其变化特征和地温梯度分布较为相似,整体表现为中东部高,西部其次,东南部最小的特征。分析揭示,区内现今地温场和热流分布主要受区域地质背景和区内构造格局的控制。 相似文献
5.
Rudolph Scherreiks Dan Bosence Marcelle BouDagher-Fadel Guillermo Meléndez Peter O. Baumgartner 《International Journal of Earth Sciences》2010,99(6):1317-1334
The Late Triassic and Jurassic platform and the oceanic complexes in Evvoia, Greece, share a complementary plate-tectonic
evolution. Shallow marine carbonate deposition responded to changing rates of subsidence and uplift, whilst the adjacent ocean
underwent spreading, and then convergence, collision and finally obduction over the platform complex. Late Triassic ocean
spreading correlated with platform subsidence and the formation of a long-persisting peritidal passive-margin platform. Incipient
drowning occurred from the Sinemurian to the late Middle Jurassic. This subsidence correlated with intra-oceanic subduction
and plate convergence that led to supra-subduction calc-alkaline magmatism and the formation of a primitive volcanic arc.
During the Middle Jurassic, plate collision caused arc uplift above the carbonate compensation depth (CCD) in the oceanic
realm, and related thrust-faulting, on the platform, led to sub-aerial exposures. Patch-reefs developed there during the Late
Oxfordian to Kimmeridgian. Advanced oceanic nappe-loading caused platform drowning below the CCD during the Tithonian, which
is documented by intercalations of reefal turbidites with non-carbonate radiolarites. Radiolarites and bypass-turbidites,
consisting of siliciclastic greywacke, terminate the platform succession beneath the emplaced oceanic nappe during late Tithonian
to Valanginian time. 相似文献
6.
Ryan M. Phelps Charles Kerans Robert G. Loucks Rui O.B.P. Da Gama Jason Jeremiah David Hull 《Sedimentology》2014,61(2):461-496
An integrated sequence stratigraphic study based on outcrop, core and wireline log data documents the combined impact of Cretaceous eustacy and oceanic anoxic events on carbonate shelf morphology and facies distributions in the northern Gulf of Mexico. The diverse facies and abundant data of the Comanche platform serve as a nearly complete global reference section and provide a sensitive record of external processes affecting Cretaceous platform development. Regional cross‐sections across the shoreline to shelf‐margin profile provide a detailed record of mixed carbonate–siliciclastic strata for the Hauterivian to lower Campanian stages (ca 136 to 80 Ma). The study window on the slowly subsiding passive margin allows the stratigraphic response to external forcing mechanisms to be isolated from regional structural processes. Three second‐order supersequences comprised of eight composite sequences are recognized in the Valanginian–Barremian, the Aptian–Albian and the Cenomanian–Campanian. The Valanginian–Barremian supersequence transitioned from a siliciclastic ramp to carbonate rimmed shelf and is a product of glacial ice accumulation and melting, as well as variable rates of mid‐ocean ridge volcanism. The Aptian–Albian supersequence chronicles the drowning and recovery of the platform surrounding oceanic anoxic events 1a and 1b. The Cenomanian–Campanian supersequence similarly documents shelf drowning following oceanic anoxic event 1d, after which the platform evolved to a deep‐subtidal system consisting of anoxic/dysoxic shale and chalk in the time surrounding oceanic anoxic event 2. Each period of oceanic anoxia is associated with composite sequence maximum flooding, termination of carbonate shelf sedimentation and deposition of condensed shale units in distally steepened ramp profiles. Composite sequences unaffected by oceanic anoxic events consist of aggradational to progradational shelves with an abundance of grain‐dominated facies and shallow‐subtidal to intertidal environments. Because they are products of eustacy and global oceanographic processes, the three supersequences and most composite sequences defined in the south Texas passive margin are recognizable in other carbonate platforms and published eustatic sea‐level curves. 相似文献
7.
在总结前人工作的基础上,结合作者对塔里木盆地和四川盆地碳酸盐岩的研究,根据地理位置、坡度、封闭性和镶边性把碳酸盐岩台地分为以下类型:缓坡开放型无镶边台地、缓坡封闭型无镶边台地、陡坡开放型无镶边台地、陡坡封闭型无镶边台地、缓坡开放型有镶边台地、缓坡封闭型有镶边台地、陡坡开放型有镶边台地、陡坡封闭型有镶边台地、礁滩型孤立台地、岩隆型孤立台地。总结了不同类型碳酸盐岩台地沉积特征并建立了沉积模式,用以指导当前碳酸盐岩的油气勘探。最后,探讨了不同类型台地形成和发育的主控因素,认为构造运动所形成的古地形(貌)和水体能量控制台地和沉积物的类型,海平面的升降控制台地类型及沉积物的变化。 相似文献
8.
Duke U. Ophori 《Hydrogeology Journal》1998,6(2):193-203
Flow of groundwater with variable density and viscosity was simulated at the Atikokan Research Area (ARA) in northwestern
Ontario, Canada. An empirical viscosity–concentration equation was modified to include total-dissolved-solids (TDS) data from
the ARA. The resulting equation was used successfully to estimate reasonably accurate viscosity values over the expected range
of temperature and concentration, in comparison with experimental values derived for sodium chloride solutions. A three-dimensional
finite-element code, MOTIF, developed by Atomic Energy of Canada Limited, was used in the simulations. The inclusion of the
effects of depth-increasing temperature and TDS-dependent fluid-density distribution, while maintaining only a temperature-dependent
viscosity relationship in a simulation, resulted in a more penetrative flow against expected buoyancy effects (i.e., the physics
of the system was not honored). Accounting for concentration in the viscosity equation caused water to be less penetrative
and more in accordance with the expected physics of the system. A conclusion is that fluid concentration should be considered
simultaneously in calculating the density and viscosity of a fluid during modeling of variable-density flow in areas underlain
by fluids with high TDS. Results of simulations suggest that both flow directions and magnitudes should be employed simultaneously
during the calibration of a model. Large-scale groundwater movement in the ARA may be analyzed with carefully selected vertical
no-flow boundaries. By incorporating the geothermal temperature gradient, groundwater recharge increases by 12%; thus, this
gradient plays a significant role in groundwater flow at the ARA. Variability in the fluid concentration at the ARA neither
decreases nor increases recharge into the groundwater system. The hypothesis that an isolated continuous regional flow system
may exist at depth in the ARA is not supported by these simulations.
Received, September 1996 Revised, September 1997, February 1998 Accepted, February 1998 相似文献
9.
淮北煤田的高温热害问题愈发突出,但目前对该区系统的地温场特征及大地热流分布研究非常稀少.在系统分析淮北煤田大量地面钻孔井温测井数据和井下巷道围岩温度测试数据的基础上,结合72块岩石样品的热导率测试结果,全面阐述了该区现今地温梯度和大地热流的分布特征.研究表明:淮北煤田现今地温梯度众值介于1.80~2.80 ℃/100 m之间,平均地温梯度为2.42 ℃/100 m;大地热流值变化范围为39.52~74.12 mW/m2,平均热流值为55.72 mW/m2,地温梯度和热流值均低于同处华北板块的其他盆地以及南部的淮南煤田;大地热流受地温梯度控制明显,两者分布较为相似,整体表现为南高北低、西高东低的特点.结果表明,区内现今地温场和热流分布主要受区域地质背景和区内构造格局的控制. 相似文献
10.
南海发育大量新生代碳酸盐岩台地，它们是南海古构造、古气候和古海洋演变的重要信息来源，也是石油天然气的重要储层。虽然前人对这些碳酸盐岩台地已经开展了大量的研究，但是目前仍未能建立南海现代碳酸盐岩台地的三维结构和高分辨率层序地层格架，关于台地发育演化的控制因素与淹没机制也存在争议。因此，亟需开展南海碳酸盐岩台地大洋钻探。南海北部西沙海域发育大量的现代碳酸盐岩台地，是一个非常好的研究靶区。本文建议选择宣德和北礁这两个典型孤立碳酸盐岩台地，在台地潟湖、边缘、斜坡和深水盆地开展钻探，建立碳酸盐岩台地的高精度年代框架，精细刻画台地内部以及周边的沉积体系，明确南海新生代碳酸盐岩台地形成、生长和淹没的历史，建立台地沉积与演化模式，揭示南海碳酸盐岩台地演化的控制因素，在此基础上，开展南海古构造、古海洋与古气候环境重建，并与全球其他碳酸盐岩台地进行对比，分析异同点及其原因。 相似文献
11.
In the recent decades， a large amount of anthropogenic heat has been absorbed and stored in the Southern Ocean. Results from observations and climate models' simulations both show that the Southern Ocean displays large warming in the upper and subsurface ocean that maximizes at 45°~40°S. However， the underlying mechanisms and evolution processes of the Southern Ocean temperature changes remain unclear， leaving the Southern Ocean to be a hotspot of climate change studies in the recent years. The present study summarized the current progress in the observations and numerical modeling of long-term temperature changes in the Southern Ocean. The effects of changes in wind， surface heat flux， sea-ice and other factors on the ocean temperature changes were presented， along with the introduction to the role of oceanic mean circulation and eddies. The present study further proposed that a deepening of the understanding in the Southern Ocean temperature change may be achieved by investigating the fast and slow responses of the Southern Ocean to external radiative forcing， which are respectively associated with the fast adjustments of the ocean mixed-layer and the slow evolution of the deep ocean. Specifically， the striking and fast mixed-layer ocean warming north of 50°S is tightly related to the surface heat absorption over upwelling regions and wind-driven meridional heat transport， resulting in enhanced warming around 45°S. While in the slow response of the Southern Ocean temperature， the enhanced ocean warming shifts southward and downward， mainly associating with the heat transfer from oceanic eddies. The Southern Ocean temperature has pronounced climatic effects on many aspects， such as global energy balance， sea-level rise， ocean stratification changes， regional surface warming and atmospheric circulation changes. However， large model biases/deficiencies in simulating the present-day climatology and essential ocean dynamic processes last in generations of climate models， which are the main challenge in advancing our understanding in the mechanisms for the Southern Ocean climate changes. Therefore， to achieve reliable future projections of the Southern Ocean climate， substantial efforts will be needed to improve the model performances and physical understanding in the relative role of various processes in ocean temperature changes at different time scales. 相似文献
12.
地热异常区的探测对于地热能开发利用至关重要。利用2 m测温法和相关仪器对厦门东山某热泉地区进行实地探测,获取1~2m深度地层温度和导热系数数据,绘制研究区2m深度温度等值线图和浅层热流密度分布云图,圈定地热异常区。运用一维稳态热传导模型对研究区20 m深度地温进行反演,并与研究区20m深度实测温度进行对比分析。结果表明,2m测温法对地热异常区探测效果明显,一维稳态热传导模型对于20m深度地温的预测结果与实测结果较为一致。该方法可以作为地热探测初期的有效手段。 相似文献
13.
WANG Chengshan HUANG Yongjian HU Xiumian LI Xianghui State Key Laboratory of Oil/Gas Reservoir Geology Exploration Chengdu Universityof Technology Chengdu Sichuan College of Earth Science Chengdu University of Technology Chengdu Sichuan Department of Earth Science Nanjing University Nanjing Jiangsu China University of Geosciences Beijing 《《地质学报》英文版》2004,78(3):873-877
The Cretaceous is among the most unusual eras in the geological past. Geoscience communities have been having great concerns with geological phenomena within this period, for example carbonate platforms and black shales in the Early and Middle Cretaceous respectively, during the last decades. But few people have paid any attention to the set of pelagic redbeds lying on the black shales, not to mention the applications to paleoclimatology and paleoceanography. It is shown by the sedimentary records of redbeds, that they were deposited around the CCD, with both a higher content of iron and much lower concentrations of organic carbon, which implies conditions with a 相似文献
14.
喜马拉雅地区的碳酸盐台地产生、发展和消亡与特提斯造山带形成的动力演化息息相关。三叠纪时,碳酸盐台地较稳定地在聂拉木陆架边缘发展起来,主要受陆源碎屑强烈干扰,碳酸盐台地在其生长面附近发育。早、中侏罗世,碳酸盐台地受构造沉降和海平面变化强烈影响,从潮下低能带向高能变浅的镶边台地旋回性发展。在台地边缘斜坡—盆地中发育一套特殊的碳酸盐“喷溢流”沉积。晚侏罗世,碳酸盐台地受被动大陆边缘初期快速热沉降影响,被黑色页岩覆盖,台地被淹没死亡。早白垩世,陆架边缘台地可能以孤立台地为特征,相当多的碳酸盐台地碎裂或崩塌,靠大陆一侧则主要为末端变陡缓坡。晚白垩世开始,碳酸盐台地主要在岗巴一带发育,发育向上变深的沉积序列,为受前陆挠曲影响产物。第三纪初,碳酸盐台地主要为缓坡,属于前陆盆地远离造山带一侧的碳酸盐台地沉积。喜马拉雅碳酸盐台地的最终消亡是由于造山抬升暴露。 相似文献
15.
A blast of gas in the latest Paleocene: simulating first-order effects of massive dissociation of oceanic methane hydrate 总被引：3，自引：0，他引：3
Carbonate and organic matter deposited during the latest Paleocene thermal maximum is characterized by a remarkable -2.5% excursion in delta 13C that occurred over approximately 10(4) yr and returned to near initial values in an exponential pattern over approximately 2 x 10(5) yr. It has been hypothesized that this excursion signifies transfer of 1.4 to 2.8 x 10(18) g of CH4 from oceanic hydrates to the combined ocean-atmosphere inorganic carbon reservoir. A scenario with 1.12 x 10(18) g of CH4 is numerically simulated here within the framework of the present-day global carbon cycle to test the plausibility of the hypothesis. We find that (1) the delta 13C of the deep ocean, shallow ocean, and atmosphere decreases by -2.3% over 10(4) yr and returns to initial values in an exponential pattern over approximately 2 x 10(5) yr; (2) the depth of the lysocline shoals by up to 400 m over 10(4) yr, and this rise is most pronounced in one ocean region; and (3) global surface temperature increases by approximately 2 degrees C over 10(4) yr and returns to initial values over approximately 2 x 10(6) yr. The first effect is quantitatively consistent with the geologic record; the latter two effects are qualitatively consistent with observations. Thus, significant CH4 release from oceanic hydrates is a plausible explanation for observed carbon cycle perturbations during the thermal maximum. This conclusion is of broad interest because the flux of CH4 invoked during the maximum is of similar magnitude to that released to the atmosphere from present-day anthropogenic CH4 sources. 相似文献
16.
Several series of one-dimensional heat and moisture flow tests were performed to examine the moisture and temperature distributions in the buffer material compacted to a dry density of 1.67 Mg m−3 and water content of 17.7%. In all tests, water was allowed to infiltrate into a horizontal soil column from one end under a constant hydrostatic head of 276 kPa. Also the specimens were heated from the other end by the heater to a constant temperature.
It is experimentally demonstrated that the moisture moves from both ends toward the mid part of the soil column due to both thermal gradient from one end and hydraulic gradient from the other end. It was observed that, in spite of no overall volume change, local volume change occurs in the system. The measured temperatures along the length of the specimen indicate that temperature distributions stabilize within a short period of time. The time required for the temperature to stabilize decreases as the heater skin temperature increases.
The diffusivity parameters are calculated using the measured moisture and temperature profiles combined with the finite difference method. Powell's optimization algorithm was used to determine the material parameters. Good agreements between experimentally measured and calibrated volumetric water content shows that the diffusion parameters can be expressed in a linear function of the volumetric water content and temperature. 相似文献
17.
地下水运动的热驱动机理 总被引：2，自引：0，他引：2
地下水在下渗过程中,受地温梯度的影响,水温度会逐渐升高,从而相同压力下的密度就会降低。这种由于温度不同所导致的密度差异会引起地下水的运动,将该种机制称之为地下水运动的热驱动机理。基于此种机理,给出地形变化较小的丘陵地区地热水近源补给的模型,解释同一或相近海拔高度上补给区与排泄区（地热水温泉）共存的现象,提出并论证在地势低洼地带得到补给、而在地势较高处出露温泉的可能性。 相似文献
18.
Geotherm families in which surface heat flow is the principal independent variable have been constructed for continental and oceanic lithospheres. The continental model is characterized by geotherms in which surface heat flow is in equilibrium with heat flowing into the lithosphere at its base plus heat generated by radioactive decay within the lithosphere. The model accommodates the regional variation of the surface heat flow with proportional variations in the radioactivity of the surficial enriched zone and in the deeper heat flow. The proportionality is dictated by a new and general linear relationship between reduced heat flow and mean heat flow for a region (
), which enables both q* and the mean heat production of the enriched zone to be estimated from knowledge of the mean surface heat flow of a province. The oceanic model is characterized by the transient cooling of a semi-infinite medium with an initial temperature gradient and some near-surface radiogenic heat production. The model yields a heat flow in satisfactory agreement with observations in the oldest ocean basins. The depth at which both the oceanic and continental geotherms reach ~0.85 of the melting temperature is shown to be a consistent estimator of the depth to the top of the low-velocity channel, or the thickness of the high-velocity lid overlying the channel. We identify the lid as synonymous with the lithosphere, and produce a global map of lithospheric thickness based on the regional variation of surface heat flow. The lithosphere is less than 100 km thick over most of the globe, but thickens appreciably and becomes more viscous beneath the Precambrian shields and platforms, regions of low heat flow. These characteristics of shields are consistent with recently reported models of the driving mechanisms of the plate system, which require greater retarding forces beneath plates with large continental areas. 相似文献
19.
Carbon-isotope stratigraphy in shallow-water carbonates: implications for Cretaceous black-shale deposition 总被引：4，自引：0，他引：4
A Barremian to Albian succession on Mount Kanala, part of a Tethyan isolated carbonate platform, was investigated for its δ13 C variations. The limestone sequence is composed of a series of peritidal shallowing-upward cycles with clear petrographic evidence for strong early diagenetic overprinting related to repeated subaerial exposure. Despite significant impact of diagenesis, the observed changes in δ13 C can be very well correlated with deep-water sections from different ocean basins and shallow water carbonate platforms in the Middle East. This lends further support to the applicability of δ13 C variations for stratigraphic purposes in shallow-water limestones. Using the δ13 C signal, time resolution in Lower Cretaceous platform carbonates can be significantly increased, independent of bio-zonations often hampered by ecological variability.
Cyclostratigraphic analysis of the Aptian part of the section shows that strong positive excursions of the cumulative departure from mean cycle thickness of the peritidal shallowing-upward cycles coincide with global positive δ13 C excursions. This, and the fact that positive shifts in the δ13 C record are preserved within shallow water limestones, provide evidence that black-shale accumulation in the ocean basins occurred during sea-level rise and flooding of platform tops. Integration of carbon-isotope-, cyclo- and sequence-stratigraphic results from different carbonate platforms indicate that strong positive global δ13 C shifts and concurrent organic-carbon burial during black-shale deposition are ultimately caused by rapid rises of eustatic sea level. Hence, the rate of change of eustatic sea level is considered to play a crucial role in black-shale accumulation in the global ocean basins during the Cretaceous. 相似文献
Cyclostratigraphic analysis of the Aptian part of the section shows that strong positive excursions of the cumulative departure from mean cycle thickness of the peritidal shallowing-upward cycles coincide with global positive δ
20.
黔南桂西早中三叠世碳酸盐台地边缘和斜坡沉积模式及其演化 总被引：3，自引：0，他引：3
牟传龙 《沉积与特提斯地质》1989,9(2):1-10
黔南桂西地区(东经105°-107°,北纬24°20＇-26°40＇)地跨扬子准地台和加里东褶皱带(华南褶皱带)两个一级大地构造单元。属于南盘江沉积盆地的北部或西北边缘。区内早、中三叠世碳酸盐地层出露良好、层序完整,为台地边缘和斜坡沉积。详细研究该区碳酸盐台地边缘和斜坡沉积,对了解台地边缘特征和演化、海平面变化以及边缘的构造作用等有着重要的理论意义,为确定三叠糸南盘江沉积盆地的西北或北部边缘的构造性质提供可靠的沉积学依据。 相似文献