燕山构造带滦平早白垩世盆地沉积过程和演化

滦平盆地是燕山构造带内一个具有代表性的早白垩世伸展盆地。对盆地内沉积岩相和相组合的详细分析结果显示,盆地内部发育不同的沉积相带并显示明显的空间变化。盆地北部和西部边缘以冲积扇砾岩和扇三角洲砂岩、砾岩沉积为主,盆地中心为湖泊细粒沉积。河流相砂岩和砾岩主要分布于盆地的东南部。古流向和物源恢复结果证明,盆地沉积物主体来自于北部和西部老变质岩基底,仅少部分沉积物来自盆地的东南缘。盆地构造沉降和沉积充填过程主要受北缘和西缘张性断层的控制,断层下盘基底岩石的抬升与盆地边界正断层活动相关,从而成为盆地主要的物源区。滦平盆地的演化可划分为三个阶段:即早期火山喷发阶段、中期强烈断陷阶段和晚期填平阶段。滦平盆地代表了早白垩世燕山构造带其它同类盆地的发展过程,它们皆以小型独立的盆地发育为特征。     

西秦岭徽县-成县早白垩世盆地沉积特征及其构造意义

徽县-成县(徽成)盆地是西秦岭造山带内一个具有代表性的早白垩世走滑拉分盆地。沉积相分析结果显示,盆地内部发育不同的沉积相组合,且呈现明显的时空变化特征。盆地充填序列分析表明,徽成盆地的沉积演化可划分为4个阶段:田家坝组沉积时期、周家湾组沉积时期、鸡山组沉积早期和鸡山组沉积晚期。田家坝组沉积时期,盆地南部以冲积扇砾岩和辫状河砂、砾岩沉积组合为主;周家湾组沉积时期,盆地西部以冲积扇砾岩和辫状河砂、砾岩沉积组合为主;鸡山组沉积时期,盆地北部和南部以冲积扇砾岩和辫状河砂、砾岩沉积为主。在整个沉积过程中,盆地中心表现为湖泊(前三角洲)相细粒沉积,而河流和三角洲体系则分布于冲积扇和深水湖泊(前三角洲)沉积之间。古流向和物源恢复结果证明,盆地沉积物主体来自于盆地北部、南部的花岗岩和前侏罗纪地层。盆地构造沉降和沉积充填过程主要受控于盆地北缘徽凤断裂,盆地南部抬升与盆地边界断层的活动密切相关,是盆地的主要物源区。     

燕山构造带凤山盆地早白垩世的沉积过程

凤山盆地是燕山构造带内的一个早白垩世伸展盆地。盆地内沉积岩相和相组合的详细分析结果显示,盆地内部发育不同的沉积相带,并显示明显的空间变化。盆地北部和西部边缘以冲积扇砾岩和扇三角洲砂岩、砾岩沉积为主,盆地中心为湖泊细粒沉积。古流向和物源恢复结果证明,盆地沉积物主体来自北部和西部变质岩基底。盆地构造沉降和沉积过程主要受北缘和西缘张性断层的控制。断层下盘基底岩石的抬升与盆地边界正断层活动相关,从而成为盆地主要的物源区。凤山盆地的演化可划分为3个阶段,即早期火山喷发阶段、中期强烈断陷阶段和晚期填平阶段。     

Coarse-grained submarine fan and slope apron deposits in a Cretaceous back-arc basin, Antarctica

The Cretaceous of west James Ross Island, Antarctica represents the proximal fill of a late Mesozoic back-arc basin that was probably initiated by oblique extension during the early development of the Weddell Sea. The succession records sedimentation in two contrasting depositional systems: a laterally persistent slope apron flanking the faulted basin margin interrupted both spatially and temporally by coarse-grained submarine fans. Slope apron deposits are dominated by thinly interbedded turbiditic sandstones and mudstones (mudstone association), interspersed with non-channelized chaotic boulder beds, intraformational slump sheets and isolated exotic blocks representing a spectrum of mass-flow processes from debris flow to submarine gliding. Localized sand-rich sequences (sandstone-breccia association) represent sandy debris lobes at the mouths of active slope chutes. The submarine fan sediments (conglomerate association) are typified by coarse conglomerates and pebbly sandstones, interpreted as the deposits of high-density turbidity currents and non-cohesive debris flows. Three assemblages are recognized and are suggested to represent components of the inner channelled zone of coarse-grained submarine fans, from major fan channels through ephemeral, marginal channels or terraces to levee or interchannel environments. The occurrence of both slope apron and submarine fan depositional systems during the Early and Mid-Cretaceous is attributed to localized input of coarse arc-derived sediment along a tectonically active basin margin. Periods of extensive fan development were probably linked to regional tectonic uplift and rejuvenation of the arc source region; cyclicity within individual fan sequences is attributed to migration or switching of fan channels or canyons. Slope apron sedimentation was controlled largely by intrabasinal tectonics. Local unconformities and packets of amalgamated slide sheets and debris flow deposits probably reflect episodic movement on basin margin faults. Differential subsidence across the basin margin anchored the basin slope for at least 20 Myr and precluded basinward progradation of shallow marine environments.     

准噶尔盆地二叠系源- 汇系统与古地理重建

源- 汇系统是目前国内外地球科学领域的研究热点,对于含油气盆地古地理重建以及源储预测评价有着重要的指导作用。本文以准噶尔盆地二叠系为研究对象,通过基于盆地地质大剖面的构造- 层序特征分析、定年数据的物源体系演化分析和沉积过程约束的正演模拟等方法,深化了对准噶尔盆地二叠纪古地理格局的认识,探讨了二叠纪源- 汇系统演化特征与二叠系源储分布规律。早二叠世为盆地断陷发育期,以石炭系为主物源,除东南部发育海相- 海陆过渡相沉积外,总体以近物源扇三角洲- 湖相沉积体系为主,多断陷的沉积格局控制了玛湖等凹陷优质烃源岩的分布,与火山岩相关的扇三角洲前缘砂体与混积云质岩构成有利储集体;中二叠世为盆地断- 拗转换期,物源年龄开始趋于复杂,沉积中心、沉降中心较早二叠世明显向盆内迁移,早期断陷趋于连通,盆地西部仍以近物源的扇三角洲群- 湖相沉积体系为主,东南部则转换为远物源三角洲群- 湖盆沉积体系,在盆地中部发育连片分布的规模烃源岩,可与同期（扇）三角洲前缘形成良好的源储组合;晚二叠世进入盆地拗陷发育期,物源供给范围更广,物源年龄进一步复杂化,大型浅水湖盆发育远物源为主的退覆型河流- 三角洲沉积体系,为盆地规模油气成藏奠定了储层基础。     

新疆西北部和什托洛盖盆地早中生代沉积特征及构造演化

和什托洛盖盆地为新疆西北部地区出露较好的一个早中生代盆地。对盆地内不同构造位置沉积剖面的岩相和相组合分析结果表明,盆地内部发育多种沉积相带并具有显著的空间变化。盆地北部或北东部边缘,以发育冲积扇相、扇三角洲相和湖相为主。盆地的南部或南西部,以发育冲积扇相和河流相为主。古水流和物源分析结果指示,盆地沉积物主体来自北部山区,部分来自盆地南部或西南部地区。通过对盆缘断裂两侧地层的分布特征和其自身要素的分析,结合平行和垂直于盆地长轴、边缘断层的地震剖面,本文认为和什托洛盖盆地的形成和发展,主要受控于盆缘两侧断裂,尤其是盆地南缘达尔布特断裂的左行走滑运动。该盆地是独立于准噶尔盆地之外发展演化的。     

Tertiary facies architecture in the Kutai Basin,Kalimantan, Indonesia

The Kutai Basin occupies an area of extensive accommodation generated by Tertiary extension of an economic basement of mixed continental/oceanic affinity. The underlying crust to the basin is proposed here to be Jurassic and Cretaceous in age and is composed of ophiolitic units overlain by a younger Cretaceous turbidite fan, sourced from Indochina. A near complete Tertiary sedimentary section from Eocene to Recent is present within the Kutai Basin; much of it is exposed at the surface as a result of the Miocene and younger tectonic processes. Integration of geological and geophysical surface and subsurface data-sets has resulted in re-interpretation of the original facies distributions, relationships and arrangement of Tertiary sediments in the Kutai Basin. Although much lithostratigraphic terminology exists for the area, existing formation names can be reconciled with a simple model explaining the progressive tectonic evolution of the basin and illustrating the resulting depositional environments and their arrangements within the basin. The basin was initiated in the Middle Eocene in conjunction with rifting and likely sea floor spreading in the Makassar Straits. This produced a series of discrete fault-bounded depocentres in some parts of the basin, followed by sag phase sedimentation in response to thermal relaxation. Discrete Eocene depocentres have highly variable sedimentary fills depending upon position with respect to sediment source and palaeo water depths and geometries of the half-graben. This contrasts strongly with the more regionally uniform sedimentary styles that followed in the latter part of the Eocene and the Oligocene. Tectonic uplift documented along the southern and northern basin margins and related subsidence of the Lower Kutai Basin occurred during the Late Oligocene. This subsidence is associated with significant volumes of high-level andesitic–dacitic intrusive and associated volcanic rocks. Volcanism and uplift of the basin margins resulted in the supply of considerable volumes of material eastwards. During the Miocene, basin fill continued, with an overall regressive style of sedimentation, interrupted by periods of tectonic inversion throughout the Miocene to Pliocene.     

中生代合肥盆地南部的沉积过程与大别山变质地体的剥露

合肥盆地南部的构造-沉积演化历史可划分出两个不同阶段,即侏罗纪伸展断陷和盆地向南扩展阶段和早白垩世盆地南缘火山喷发和盆地向北退缩阶段。合肥盆地自早侏罗世开始形成,强烈的断陷-沉积作用发生在中、晚侏罗世。盆地边缘沉积主要由冲积扇与辫状河体系组成,明显受边缘正断层控制,并且随断层向南迁移,盆地也不断向南扩展。盆地主体沉积以河流-湖泊体系为特征。古流向恢复结果证明盆地沉积物来自于大别山变质地体。下侏罗统防虎山组中含柯石英包体的三叠纪变质锆石的发现表明,超高压岩石在早侏罗世就已经剥露到地表。凤凰台组中榴辉岩砾石的出现指使大别山在晚侏罗世经历了强烈的抬升和剥蚀。合肥盆地南部在早白垩世时开始抬升,并发生强烈的火山喷发,盆地沉积范围向北明显迁移。合肥盆地二阶段式构造-沉积演化过程反映,大别山及邻区的构造体制在侏罗纪末发生了明显的变化。我们认为大别山变质地体在侏罗纪时期可能是通过构造挤出的方式折返到地表的,这种挤出构造过程一方面导致大别山变质地体的前缘(南缘)发育逆冲推覆构造和形成前陆盆地,另一方面也同时造成其后缘(北缘)发生伸展拆离和产生断陷盆地。早白垩世时期大别山所经历的区域性地壳伸展和强烈的岩浆活动可能与深部岩石圈的拆沉和软流圈热物质的上涌有关。     

Structure and evolution of the Sunwu-Jiayin basin in NE China and its relation to the Zeya-Bureya basin in the Far East of Russia

The Sunwu-Jiayin Basin is located on the Amur River’s right side and comprises four depressions separated by two NE-trending uplifts. The basin is bounded by first-order steep to vertical faults (mostly normal faults) formed under extension conditions. These faults control the structural pattern of the basin. The sedimentary cover of the depressions developed during five stages: extension, early inversion, thermal subsidence, late inversion, and formation of depressions. The Late Paleozoic and Precambrian basement of the Sunwu-Jiayin basin composed of granitoides and metamorphosed shales crops out within the uplifts and plunges within the depressions to a depth ranging from 0.5 to 3.4 km. The basin under consideration is considered to be the southern margin of the Zeya-Bureya Basin according to the conditions of its formation and the structural features.     

辽西义县盆地义县组底部沉积相与沉积环境分析

辽西义县盆地下白垩统义县组底部发育有马神庙、老公沟两个沉积层。马神庙沉积层从下至上可以划分出6个沉积亚层,其下部复成分砾岩沉积层为干旱气候条件下形成的洪（冲）积扇底部沉积相、洪（冲）积扇上的山洪冲槽充填相;中部为复成分砾岩夹凝灰质沉积层;顶部被中基性的火山岩覆盖。老公沟沉积层下部是以泥质粉砂岩为主的滨浅湖相、洪（冲）积扇向湖盆过渡的季节性河流作用形成的粗砂岩—含砾粗砂岩沉积相;顶部为一套滨浅湖相的膨润土化粉砂岩—膨润土—碳酸盐岩沉积岩石组合。义县盆地演化初期气候干旱,盆地边缘地势起伏较大,盆地边缘形成洪（冲）积扇、扇面上发育洪槽充填沉积作用,洪（冲）积扇向湖盆过渡区存在季节性河流;老公沟顶部湖泊相沉积指示受区域季节性变化的半干旱、频繁火山作用影响下,湖盆水深频繁波动的古地理、古气候的沉积特征。义县组底部沉积相表现了该盆地边缘向中心横向上的洪（冲）扇、季节性河流和湖泊沉积的三相发育的古地理特征。     

东秦岭柞水-镇安地区泥盆纪沉积环境和沉积盆地演化

东秦岭陕南柞水-镇安地区泥盆纪沉积盆地中主要发育有冲积扇、小型辩状河、河口湾、潮坪、潮下洼地、台地边缘生物滩、生物礁、开阔台地、斜坡和盆地沉积环境。台地沉积主要由陆源碎屑和碳酸盐混合类型岩石组成,斜坡-盆地为巨厚的陆源碎屑浊积岩充填。根据沉积作用特征和大地构造差异,在构造活动期和构造稳定期的沉积模式就反映了沉积盆地演化特征。 根据沉积作用,沉积环境的发展变化,结合区域构造特征、地层层序、岩浆活动和变质作用、地球物理和化学资料,论证了当时沉积盆地为南北向展布（与秦岭造山带总体方向垂直）,具向东走滑的大陆边缘裂谷-断陷盆地。盆地的发展演化阶段为:（1）岩石圈裂前拱起-陆内裂谷早期阶段（Z₂-S）;（2）大陆边缘裂谷-断陷盆地的中期阶段（D₁-D₃）;（3）晚期回返-陆内俯冲阶段（C-T₂）。盆地的关闭是由于强烈陆内俯冲,同时盆地被挤压进东西向展布的秦岭造山带。     

江西象山地质公园丹霞地貌成景地层沉积环境分析

随着旅游地学的兴起和地学科普的需求,红层与丹霞地貌正在吸引着越来越多的关注。赣东北贵溪市象山地质公园发育以赤壁丹崖为特色的丹霞地貌景观,成景地层为上白垩统圭峰群河口组以砾岩为主的红色碎屑岩,冲刷侵蚀界面、粒序层理和交错层理等沉积构造发育,这为沉积环境分析提供了良好的判断标志。对该套成景地层进行厘米级实测,另外选择2处砾岩露头进行砾石统计以获取碎屑颗粒粒径、岩性、磨圆度和风化程度等信息。在实测厚度为40余米的地层柱状图上,识别出7种岩相类型,即正粒序砾岩、逆粒序砾岩、无沉积构造砾岩、平行层理砾岩、交错层理砾岩、聚集状砾岩、砂岩。砾石以中砾(2~5 cm)为主,磨圆度低,风化程度中等,成分以凝灰岩为主(58%~665%),其次为石英、花岗岩、砂岩。砾石成分和砾向分析结果说明,盆地南部早白垩世凝灰岩提供了主要的碎屑物质。根据野外实测红层剖面和砾石统计分析,认为成景地层为冲积扇沉积体系的产物。河口组红层沉积时期,盆地边缘断层活跃,间歇性强降雨事件导致冲积扇朵叶上洪泛河流搬运的沉积物供应充足,最终在剖面上形成砾岩和砂岩频繁互层及其厚度横向不稳定的现象。在中国东南地区晚白垩世总体干燥的古气候背景下,河口组中河流作用主导的冲积扇沉积体系可能指示了古气候向湿润转变,降水增加,相对丰富的水系将粗碎屑搬运到盆地区发生沉积。     

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     

燕山构造带中段早白垩世盆地特征

燕山构造带中段主要包含3个早白垩世盆地,即滦平盆地、凤山盆地、石人沟盆地.通过对盆地的沉积相分析、古水流的恢复以及盆地构造-沉积演化研究,认为燕山构造带中段早白垩世盆地发育分为三个阶段,即早期火山喷发阶段、中期强烈断陷阶段和晚期填平阶段.早期发育强烈的火山作用,形成以酸性火山岩为主的张家口组;中期盆地主体呈半地堑状,受单一边界主断层控制,盆地相互独立,盆地边缘以冲积扇砾岩和扇三角洲砂岩、砾岩沉积为主,盆地中心为湖泊细粒沉积.古流向和物源恢复结果证明,盆地沉积物主体来自于北部和/或西部的变质岩基底.盆地构造沉降和沉积充填过程主要受边界正断层的控制,断层下盘基底岩石的抬升与盆地边界正断层活动相关,从而成为盆地主要的物源区.     

鄂尔多斯地块中元古代长城纪盆地属性研究

中元古代长城纪华北克拉通南缘的大地构造背景一直备受关注。学者们主要依据该时期火成岩地球化学性质推断其构造背景,提出了B型俯冲、安第斯型俯冲、非造山环境以及与Columbia超大陆裂解有关的伸展环境。本次研究应用地球物理方法来剖析鄂尔多斯盆地中南部长城系构造格架和地层分布,以探索研究区大地构造背景及盆地属性。二维地震资料显示长城纪构造旋回包含裂陷期和裂后期。裂陷期半地堑主控边界断层活动强度大,下降盘发生旋转掀斜,发育次级地堑、半地堑,同时发育扇三角洲、水下扇沉积,楔状体沉积中心地层厚度大。裂后期断层活动减弱,水体范围扩大,地层超覆在早期楔状地层之上,地层厚度变化小。重力异常反演表明,研究区存在同期的凹陷和凸起,它们可能受控于边界断裂。结合地块周缘长城系沉积特征,我们认为鄂尔多斯地块中元古代长城纪盆地属性为陆内裂陷。     

The Neogene Fohnsdorf Basin: basin formation and basin inversion during lateral extrusion in the Eastern Alps (Austria)

The evolution of the early/middle Miocene Fohnsdorf Basin has been studied using borehole data, reflection seismic lines, and vitrinite reflectance. The basin is located along the sinistral Mur-Mürz fault system and probably formed as an asymmetric pull-apart basin, which was subsequently modified by halfgraben tectonics, as a consequence of eastward lateral extrusion. Sedimentation started with the deposition of fluvio-deltaic sediments. Thick coal accumulated in the northwestern basin. Thereafter subsidence rates increased dramatically with the formation of a lake several hundred meters deep. The lake was filled mainly from the north with more than 1500?m of sediments showing a coarsening-upward trend due to southward prograding deltaic lobes. A sequence of more than 1000?m of boulder gravels (Blockschotter) in the southeastern part of the basin are interpreted as the upper part of a coarse-grained fan delta succession, which accumulated along a normal fault along the southern basin margin. Fan deltas reached the central basin only during the early stages of sedimentation and during the late stages of basin formation. Miocene heat flow was approximately 65–70?mW/m², which is significantly lower than in other basins along the Mur-Mürz fault system. The present-day southwestern basin margin is a recent feature, which is related to transpression along the dextral Pöls-Lavanttal fault system. It is formed by reverse faults constituting the northeastern part of a flower structure. Miocene sediments in the Feeberg valley are preserved along its southwestern part. Uplift of the central part of the flower structure was at least 2.4?km. North–south compression resulted in the deformation of the basin fill, uplift of the E/W-trending basement ridge separating the Fohnsdorf and Seckau basins, and in the erosion of 1750?m of sediments along the northern basin margin.     

Facies and basin architecture of the Late Carboniferous Salvan-Dorénaz continental basin (Western Alps, Switzerland/France)

The Salvan‐Dorénaz Basin formed during the Late Palaeozoic within the Aiguilles‐Rouges crystalline basement (Western Alps) as an asymmetric, intramontane graben elongated in a NE–SW direction and bounded by active faults. At least 1700 m of fluvial, alluvial fan and volcanic deposits provide evidence for a strong tectonic influence on deposition with long‐term, average subsidence rates of > 0·2 mm yr^?1. The early basin fill was associated with coarse‐grained alluvial fans that were dominated by braided channels (unit I). These issued from the south‐western margin of the basin. The fans then retreated to a marginal position and were overlain by muddy floodplain deposits of an anastomosed fluvial system (unit II) that drained towards the NE. Deposition of thick muds resulted from a reduction in the axial fluvial gradient caused by accelerated tectonic subsidence. Overlying sand‐rich meandering river deposits (unit III) document a reversal in the drainage direction from the NE to the SW caused by synsedimentary tectonism, reflecting large‐scale topographic reorganization in this part of the Variscides with subsidence now preferentially in the W and SW and uplift in the E and NE. Coarse‐grained alluvial fan deposits (unit IV) repeatedly prograded into, and retreated from, the basin as documented by coarsening‐upward cycles tens of metres thick reflecting smaller scale tectonic cycles. Volcanism was active throughout the evolution of the basin, and U/Pb isotopic dating of the volcanic deposits restricts the time of basin development to the Late Carboniferous (308–295 Ma). ⁴⁰Ar/³⁹Ar ages of detrital white mica indicate rapid tectonic movements and exhumation of the nearby basement. In unit I, youngest ages are close to that of the host sediment, but the age spectrum is wide. In unit II, high subsidence and/or sedimentation rates coincide with very narrow age spectra, indicating small, homogeneous catchment areas. In unit III, age spectra became wider again and indicate growing catchment areas.     

Tectonics and sedimentation in the Fohnsdorf-Seckau Basin (Miocene, Austria): from a pull-apart basin to a half-graben

The Miocene intramontane Fohnsdorf-Seckau Basin is situated at the junction of the sinistral Mur-Mürz-fault system and the dextral Pöls-Lavanttal fault system. The basin comprises a 2,400-m-thick coal-bearing fluviodeltaic-lacustrine succession (Lower to Middle Miocene, Upper Karpatian?/Lower Badenian) which is overlain by a 1,000-m-thick alluvio-deltaic conglomeratic succession (Apfelberg Formation, ?Middle/Upper Badenian) in the south. A three-stage model for the basin evolution has been reconstructed from structural analysis and basin fill geometries. During a first pull-apart phase, subsidence occurred along ENE-trending, sinistral strike-slip faults of the Mur-Mürz fault system and NE-SW to N-S-trending normal faults, forming a composite pull-apart basin between overstepping en-echelon strike-slip faults. The Seckau and Fohnsdorf sub-basins are considered as two adjacent pull-aparts which merged into one basin. During the second phase, N-S to NNW-SSE extension and normal faulting along the southern basin margin fault formed a half-graben, filled by wedge-shaped alluvial strata (Apfelberg Formation). During the third phase, after the end of basin sedimentation, the dextral Pöls-Lavanttal fault system reshaped the western basin margin into a positive flower structure.     

青海囊谦古近纪盆地沉积特征及沉积环境分析

囊谦盆地是在藏东北段沿金沙江-红河构造带分布着一系列呈NNW向展布的中小型古近纪盆地的典型代表.通过野外地质调查、分析测试和室内综合研究,在盆地演化的格架内,系统分析了囊谦盆地贡觉组古气候、沉积相标志、物源以及沉积环境等方面的特征,认为贡觉组可划分为三段式结构,沉积环境为冲积扇-河流-湖泊-三角洲环境;砾石成分较复杂,...     

辽西北票盆地中侏罗统海房沟组砾岩沉积特征与成因

通过对总长2 705 m两条剖面的实测、40块薄片鉴定、419个砾石统计及其粒度分析,确定了辽西地区北票盆地中侏罗统海房沟组砾岩的沉积特征及成因。研究表明：辽西北票盆地海房沟组主要岩性为一套冲积扇相的复成分砾岩,并夹一套喷溢相下部亚相安山质角砾熔岩和另一套爆发相空落亚相安山质角砾凝灰岩、热碎屑流亚相安山质角砾凝灰熔岩;海房沟组沉积物源来自研究区SSW向的太古宇变质岩及结晶基底和下侏罗统兴隆沟组火山岩的全面快速隆升剥蚀。结合构造背景,通过对北票组与海房沟组界线的研究和岩性岩相的鉴定,确定海房沟组冲积扇相的复成分砾岩是燕山运动二期挤压伸展构造运动的重要产物,两套中酸性火山岩的出现是两次火山喷发的重要标识。