隐爆角砾岩——古地震的一种成因标志SCIEI北大核心CSCD

全球到处发育的隐爆角砾岩表明隐爆作用的普遍性,并标志着古地震的一种形成机制。隐爆角砾岩具有特殊的角砾形状和构造。地震地质资料表明大地震产生的地表破裂带没有肉眼可观测到的断层位移。材料聚集应变能估算值表明岩石聚集的应变能不足以产生大地震。携带高能量的地核-地幔流体不仅为自己逸散提供了能量,而且为产生地震提供了充足的能量。深部流体以运移-聚集-爆炸-运移-聚集-爆炸的循环方式向地表逃逸,在地球内部不同深度产生了不同震级的地震。因此,超高压流体隐爆应该是地震形成的主要机制。地震隐爆成因机制不仅能够更好地解释各种天然地震(中深源地震、震群、慢地震和非双力偶性地震等)以及全球地震、火山和地热带的空间吻合,而且能够解释隐爆角砾岩及其伴生矿的形成。     

570矿床控制因素及富矿形成条件

570矿床地质背景是破火山旋回边缘活动带;矿床定位要素是受破火山断裂系统构造结控制的隐爆角砾岩筒;隐爆加断陷组成的聚矿结构,是富矿形成的主要条件;隐爆角砾岩筒与次火山花岗岩浆侵位组成的热泵汲取效应,是矿床基本成因模式。矿床扩大方向是在探索隐爆角砾岩筒深部的同时,沿边缘活动带,在破火山断裂系统构造结处寻找新的隐爆角砾岩筒。     

东秦岭216.8Ma前7.0级隐爆成因大地震的震源遗迹

地震预测是公认的世界性科学难题,而地震成因问题又是地震预测的基础与关键。由于人们不能进入因而不能直接观察和研究发生地震的震源,使得认识地震的成因非常困难。本文依据地质勘查、地球物理探测和工程揭露等事实,在东秦岭熊耳山南麓发现一个形成于216.8±4.0Ma(等时线年龄227±8.4Ma)前古地震的震源遗迹。通过隐爆角砾岩体、隐爆系列角砾岩、岩石地球化学、同位素示踪、同位素测年、稀土元素、多相包裹体、角砾岩微观破碎特征等分析表明,该震源遗迹是一个在杨子板块与华北板块碰撞对接的印支-燕山主造山阶段晚期,上地幔或下地壳经深熔形成的I型造山带花岗质母岩浆结晶分异产生高温高压气液流体乃至超临界流体,沿断裂等薄弱部位上升到局部硅化封闭空间内积聚,产生高温高压气液流体膨胀压力并逐渐积累,当积累的巨大压力超过其所处深度的静岩压力与围岩破裂强度可承受的压力之和时,便在深部产生剧烈的隐蔽爆炸即隐爆所形成。根据上覆地层厚度、临近可参照深成岩体的侵位时代与深度、现代相对高度比较、震源遗迹主震的现代地表尺度并参照地下核爆炸试验相关数据等估算,东秦岭熊耳山震源遗迹的隐爆深度位于当时地表约10km之下,形成震源遗迹隐爆主震的隐爆总能量约为1.55×1017J,相应的主震面波震级MS为7.0。同理得知中国印支-燕山期19个典型隐爆角砾岩型多金属矿床隐爆所产生地震的强度为MS5.1~7.6级之间,据此统计分析得到它们产生地震的等效球状隐爆地质体的压碎区半径R与面波震级MS的经验关系为MS=1.40+0.95ln(R)。与一般"地震遗迹"不同,东秦岭熊耳山南麓地震遗迹不仅是一个震源的实体遗迹即"震源遗迹",而且是一个震源深度、发生年代、地震强度等地震要素完整、一致且现今可视、可入的震源遗迹。该震源遗迹以及中国印支-燕山期一系列隐爆角砾岩体以相近方式形成地震的震源遗迹,为岩浆分异气液流体和超临界流体隐爆形成地震的地震成因类型存在提供了实例依据,并为该类地震成因机制的深入研究乃至地震预测提供了可直接观测研究的震源实体。     

宜章县长城岭浅成花岗质岩浆隐爆机制及找矿意义探讨

在长城岭铅锌多金属矿区,常见沿花岗斑岩脉与北东向断裂交汇处发育与成矿关系密切的角砾岩。这类角砾岩的空间就位、物质组成、岩石组构及蚀变特征等表明其为隐爆成因,可划分为爆破角砾岩、震碎角砾岩和混杂角砾岩。按照隐爆机制的不同,其又可分为岩浆隐爆角砾岩和热液隐爆角砾岩。区内花岗斑岩的地质地球化学特征表明,燕山早期晚阶段侵入的富含挥发分、流体-溶体相互作用强烈的浅成花岗斑岩具备有利的隐爆条件和明显的隐爆特征。隐爆作用不仅为铅锌多金属矿化富集提供物源及流体源,还为成矿流体汇聚及卸载沉淀提供了重要场所。长城岭地区与铅锌多金属成矿关系密切的隐爆角砾岩的发现对其矿区深部、湘南钨锡多金属矿化集中区乃至南岭中段有色金属找矿研究具有重要意义。     

广西龙头山次火山-隐爆角砾岩型金矿床

龙头山金矿床与燕山晚期流纹斑岩、角砾熔岩等次火山岩相有关。据围岩和构造条件将矿体分为次火山隐爆角砾岩类、接触带－构造角砾岩类和围岩中断裂构造角砾岩等３种类型。主要金矿化与电气石化、硅化关系密切。通过矿石组成、Ａｕ及其伴生元素分布特征,以及Ｓ、Ｐｂ、Ｈ、Ｏ、Ｃ等稳定同位素、流体包裹体地球化学和成矿物理化学条件等综合研究结果,认为龙头山矿床是与次火山隐爆角砾岩有关的气成－高温热液型金矿床。     

拉拉铁铜矿床成因:来自隐爆角砾岩结构定量化和锆石U-Pb年代学的证据

拉拉铁铜矿床被认为是中国西南地区规模最大的元古代内生金属矿床。该矿床主要赋存于古元古代河口群地层中,传统上被归属为火山喷流-沉积成因。近年来,一些学者陆续发现拉拉铁铜矿床中有Au、REE、Mo等金属的富集,因而将其归属为IOCG矿床。但是,对该区出露的隐爆角砾岩及其与成矿作用的关系缺乏详细报道,因而对矿床成因和成矿时代的判断尚显依据不足。作者对拉拉铁铜矿床的小露天采坑及其邻近地区进行了详细野外地质观察和剖面测量,发现采坑内出露的角砾岩具有隐爆角砾岩的特征。角砾主要来自下伏河口群的细碧-角斑岩建造,呈棱角状-次圆状,由热液物质胶结,且胶结物中见有矿化现象。定量化结构分析表明,隐爆角砾岩中的角砾具有机械破碎成因的特点,其分形特征与火山碎屑岩类似,定向程度和圆度明显不同于断层角砾岩。对角斑岩和隐爆角砾岩分别进行了锆石U-Pb年代学分析。来自角斑岩中的锆石晶体具有典型的岩浆锆石特征,产生了1720±11Ma的锆石U-Pb年龄;而来自隐爆角砾岩的锆石晶体展示了较显著的后期热液改造特征。岩相学观察表明,细碧岩和角斑岩在成矿作用之前经受过强烈构造变形,表现为岩石的片理化,而沿片理面充填的含矿细脉则没有任何变形的迹象。据此可以得出结论:(1)拉拉铁铜矿床的形成时间明显晚于细碧-角斑岩建造,不支持火山喷流-沉积成因的观点;(2)矿区内产有与成矿作用紧密相关的隐爆角砾岩,后者被认为是IOCG型矿床的重要标志之一。前人报道的成矿元素组合特征以及本文提供的新证据支持该矿床为IOCG型矿床的认识。其成矿过程为成矿流体在流体库中膨胀后并由下部上侵,下部流体遇薄弱带侵入成矿,上部流体在密闭空间内形成超压进而发生爆破,并侵入细碧岩的片理中成矿,这种成因过程类似于透岩浆流体成矿模型。     

论长英质隐爆角砾岩的气热流体溶浸成矿机制——以赣南6722铀矿床为例

通过对6722铀矿床地质－地球化学特征及长英质隐爆角砾岩和围岩超微构造研究，结合U，Th等元素溶浸实验结果，得出“隐爆气热流体溶浸成矿富集机制”；来自深部的富含挥发组分（H2O、F、CO2等）的高热安粗岩浆，在早白垩世末（107Ma）沿富城花岗岩体西部蚀变带发育的火山机构中发生隐爆作用，致使围岩发生强烈脆性变形，生成长英质隐爆角砾岩带和震裂花岗岩带；压力、温度降低导致安粗岩浆中挥发组分逸出形成气热流进入稳隐爆裂隙中，并将蚀变花岗岩中的活动性成矿元素（U）浸出转移；成矿物质在物理化学条件（p,t,Eh,pH,化学组分等）急剧变化的部位（长英质隐爆角砾岩及碎裂花岗岩）沉淀富集。     

云南东川白锡腊碱性钛铁质辉长岩类岩株与侵入构造控矿特征

白锡腊矿段深部铁铜矿体属于与碱性钛铁质辉长岩侵入体有关的铁氧化物铜金型(IOCG)矿床。采用井巷工程构造岩相学填图技术,对云南东川白锡腊碱性钛铁质辉长岩类侵入体的侵入构造系统和控矿规律进行研究,认为滥泥坪-白锡腊铁铜矿段深部IOCG矿体产于碱性钛铁质辉长岩类侵入体的边缘,古火山机构、碱性钛铁质辉长岩侵入体、隐爆角砾岩体、多期叠加断裂构造和裂隙破碎带等是白锡腊IOCG矿床的控制构造组合样式。在辉长岩类侵入体中发育的脆韧性剪切带、热液角砾岩带和断裂-裂隙带等构造岩相学部位,构造-热流体耦合和水岩反应强烈,形成了蚀变构造岩相带。IOCG矿体的储矿构造类型为辉长岩类侵入体的膨大与转折部位的底部和产状变化部位、隐爆角砾岩和构造裂隙破碎带等。辉长岩侵入体的过渡相、含矿隐爆角砾岩相和蚀变构造岩相带等,它们是隐伏IOCG矿床的直接找矿预测标志。预测在白锡腊矿段深部和白锡腊-哑巴峡倒转背斜-断裂破碎带北翼深部具较大找矿前景,是寻找大型IOCG矿床有望靶区。     

东秦岭216.8Ma前一个7级隐爆大地震的震源遗迹

依据野外地质勘查、工程揭露、地球物理探测等事实和地球化学测量资料,发现位于华北板块南缘东秦岭216.8Ma前一个古地震的震源遗迹。结合隐爆角砾岩体、系列隐爆角砾岩、岩石地球化学、同位素示踪、同位素测年、稀土元素、包裹体、岩石微观破碎等特征分析表明,该震源遗迹是在印支晚期杨子板块与华北板块碰撞对接的造山阶段,上地幔或下地壳形成的源于变质火山岩深熔的I型造山带花岗岩浆,在结晶分异过程中产生大量气液流体并沿断裂通道上升,进入硅化封闭的局部断裂空间后形成岩浆分异气液流体压力,当积聚的巨大压力超过所处深度的静岩压力与聚压空间围岩的破裂强度极限后,在地壳深部产生强烈隐爆所形成。根据上覆地层厚度、可参照的深成侵入岩体相对高度对比和主震遗迹的尺度等分析,隐爆深度位于当时地表的10km以下,隐爆主震的面波震级MS＞7.0。该震源遗迹的发现,可初步确认岩浆气液隐爆成因地震存在,并有助于克服一些地震成因研究中的震源不可视与不可入性难题,为地震成因乃至地震预测探索提供一些可直接观测研究的震源实体。 该遗迹不是一般的地震遗迹,而是一个“震源”实体遗迹——震源遗迹,而且是一个具有震源深度、发生年代、地震强度等地震要素完整且一致的可见震源遗迹。     

黔西南戈塘金矿成因再认识

文章通过对戈塘金矿硅质角砾岩的地质特征、地球化学特征综合分析,认为矿区的角砾硅化灰岩、硅化黏土岩等蚀变地质体为热液成因,其中硅质来源可分为成岩期与成矿期:成岩期硅质来自热泉型生物沉积;成矿期硅质来自成矿流体。成矿流体是来源于深部流体与天水、地层建造水的混合作用形成的混合流体。根据矿石结构构造特征及含金蚀变地质体产状特征,结合在戈塘地区茅口组底部及以下地层中新近发现呈筒状产出的含金蚀变角砾岩,认为戈塘金矿矿区含金角砾岩具有隐爆角砾岩的特征,得出戈塘金矿成因类型可能为隐爆角砾岩型金矿的新认识。此认识可供黔西南金矿成矿理论研究、探讨新的找矿方向和成矿预测提供参考。     

Earthquake swarms in continental rifts — A comparison of selected cases in America, Africa and Europe

The occurrence of earthquake swarms is typically related to magmatic activity in volcanoes, yet swarms are also common in other intracontinental regions such as continental rifts. We present here a summary of geophysical observations that have been made in earthquake swarm areas of the Rio Grande, Kenya, and Eger rifts, focusing on characteristic parameters for the origin and generation of the swarm earthquakes.Our compilation of seismological parameters such as spatial distribution and focal parameters of hypocenters, magnitude statistics, and the location of the swarm centres in the rift environments reveals major similarities. The earthquake swarms take place at shallow depth between 0 and 10 km. The maximum magnitudes are mostly less than 4.5. The b-values, indicating the magnitude frequency relation of the seismicity, are about 0.8. They are hence not deviating from a normal non-volcanic intraplate environment, but are considerably lower than those of volcanic earthquake swarms. Focal mechanism studies give uniform pictures of stress field orientation and faulting style for the swarm areas. In all three rifts, the centres of swarm activity seem to be restricted to rift valley sections that may be influenced by large-scale fracture or shear zones that intersect the rifts. We conclude that these deep-reaching zones of weakness allow intrusions of upper mantle material into crustal layers, where magma-related fluids or fluctuations of the magma bodies themselves cause the generation of earthquake swarms.     

中国深层地热能开采的地质条件评价

深层地热能是指深度大于3 000 m的地热能。我国深层地热能资源丰富,但是开采条件怎么样呢?本文基于地热地质学原理,结合岩石力学等相关学科的理论,提出一种对深层地热能开采条件进行评价的指标体系,对各单一指标采用专家打分的方法赋值,继而采用模糊数学定量计算和评估深层地热能资源开发的难易程度。该方法考虑了深层地热能开发利用中的增强地热系统(EGS)的环境安全问题,即传统的“刚性造储”可能带来的诱发地震等不利于地热能行业健康发展的因素,倡导“柔性造储”和广义EGS理念,强调储层属性和地物理场的整合,针对我国地热能分布与构造活动关系密切、地壳总体上活动性强、地应力高、地震频发等构造型地热特点,是对以往评价方法的补充和拓展。该方法充分利用了专家知识,发挥了模糊数学综合评估作用,给出的量化结果易于对比和使用,可以更好地支持决策。本文基于新的评估方法,利用现有的深部地热研究及勘探成果,评估了中国大陆地区九个区域深层地热能开发的难易程度,评价区包括西藏南北地堑系、云南西部火山型地热区、青海东部共和盆地以及东北、华北等。从本文的结果可以看出,我国深层地热能开采的地质条件复杂,开采难度较大。     

冰岛区域地质及矿产资源特征

冰岛是欧洲的第二大岛屿,在成因类型上,是由于地幔柱上涌而形成的碱性玄武岩区,属于周期性的海底岩浆活动和海底火山喷发而形成的火山岛。全岛主要由玄武岩组成,并可分为4个主要地层单元,分别为中新世—早上新世岩层、晚上新世—早更新世岩层、晚更新世岩层及冰后期岩层。构造方面,冰岛火山断裂系统发育,可分为3个火山侧翼带和4个火山裂谷带。冰岛地热资源极丰富,其具有分布广、类型多、温度高、地热流体多为淡水等特征。近年来,冰岛发现了一系列金矿(化)点,主要分布在冰岛沿海地区,可分为3个成矿带,与地热系统具有密切的时空分布关系,成因类型多为浅成低温热液型金矿床,与中国新疆西天山地区阿希金矿床具有相似的成矿环境和地质特征。在系统收集前人资料的基础上,简要介绍了冰岛地质特征及演化历史,阐述了冰岛地热、金矿资源分布规律,旨在为中国地质科技人员了解冰岛的地质和矿产资源特征提供参考依据。     

Structural characteristics off Miyagi forearc region, the Japan Trench seismogenic zone, deduced from a wide-angle reflection and refraction study

The Japan Trench subduction zone, located east of NE Japan, has regional variation in seismicity. Many large earthquakes occurred in the northern part of Japan Trench, but few in the southern part. Off Miyagi region is in the middle of the Japan Trench, where the large earthquakes (M > 7) with thrust mechanisms have occurred at an interval of about 40 years in two parts: inner trench slope and near land. A seismic experiment using 36 ocean bottom seismographs (OBS) and a 12,000 cu. in. airgun array was conducted to determine a detailed, 2D velocity structure in the forearc region off Miyagi. The depth to the Moho is 21 km, at 115 km from the trench axis, and becomes progressively deeper landward. The P-wave velocity of the mantle wedge is 7.9–8.1 km/s, which is typical velocity for uppermost mantle without large serpentinization. The dip angle of oceanic crust is increased from 5–6° near the trench axis to 23° 150 km landward from the trench axis. The P-wave velocity of the oceanic uppermost mantle is as small as 7.7 km/s. This low-velocity oceanic mantle seems to be caused by not a lateral anisotropy but some subduction process. By comparison with the seismicity off Miyagi, the subduction zone can be divided into four parts: 1) Seaward of the trench axis, the seismicity is low and normal fault-type earthquakes occur associated with the destruction of oceanic lithosphere. 2) Beneath the deformed zone landward of the trench axis, the plate boundary is characterized as a stable sliding fault plain. In case of earthquakes, this zone may be tsunamigenic. 3) Below forearc crust where P-wave velocity is almost 6 km/s and larger: this zone is the seismogenic zone below inner trench slope, which is a plate boundary between the forearc and oceanic crusts. 4) Below mantle wedge: the rupture zones of thrust large earthquakes near land (e.g. 1978 off Miyagi earthquake) are located beneath the mantle wedge. The depth of the rupture zones is 30–50 km below sea level. From the comparison, the rupture zones of large earthquakes off Miyagi are limited in two parts: plate boundary between the forearc and oceanic crusts and below mantle wedge. This limitation is a rare case for subduction zone. Although the seismogenic process beneath the mantle wedge is not fully clarified, our observation suggests the two possibilities: earthquake generation at the plate boundary overridden by the mantle wedge without serpentinization or that in the subducting slab.     

地球系统动力学与取热减灾减排

在综合分析大量地质、地球物理资料的基础上,建立了以热能为驱动力的开放地球系统发生多级物质循环的地球系统动力学新模式,据此可以合理地解释洋陆系统及其相关的盆山体系的动力学机制,阐明地球系统资源灾害环境发展的内在关系。在地球系统动力学创新思想指导下,总结了活动地壳热构造系统的特征,初步研究了华北和西南热灾害链的结构和强震发展趋势,系统地分析了取热减灾减排的重要性、必要性和可行性,在此基础上阐明了系统开发干热岩的思路和方法及其可持续发展的途径。从而为即将到来的新地学革命和能源革命提供了一个新思路。     

Accretion of crust in the axial zone of the Mid-Atlantic Ridge south of the Martin Vas Fracture Zone,South Atlantic

New data are obtained on the structure, evolution, and origin of zones of nontransform offsets of adjacent segments in the Mid-Atlantic Ridge (MAR), which, in contrast to transform fracture zones, so far are studied insufficiently. The effects of deep mantle plumes developing off the crest of the MAR on the processes occurring in the spreading zone are revealed. These results are obtained from the geological investigation of the crest of the MAR between 19.8 ° and 21° S, where bottom sampling, bathymetric survey, and magnetic measurements have been carried out previously. Two segments of the rift valley displaced by 10 km relative to each other along a nontransform offset are revealed. A volcanic center of a spreading cell, which has been active over the last 2 Ma, is located in the northern part of the southern segment and distinguished by a decreased depth of the rift valley and increased thickness of the crust. Magnesian, slightly evolved basalts of the N-MORB type are detected in this center, whereas evolved and high-Fe basalts are found beyond it. The variation in the composition of the basalts indicates that the volcanic center is related to the upwelling of the asthenospheric mantle, which spread along and across the spreading ridge. In the lithosphere, the melt migrated off the volcanic center along the rift valley. In the northern segment, a vigorous volcanic center arose 2.5 Ma ago near its southern end; at present, the volcanic activity has ceased. As a result of the volcanic activity, an oval rise composed of enriched T-MORB-type basalts was formed at the western flank of the crest zone. The isotopic signatures show that the primary melts are derivatives of the chemically heterogeneous mantle. The mixing of material of the depleted mantle with the mantle material pertaining either to the Saint Helena or the Tristan da Cunha plumes is suggested; the mixture of all three sources cannot be ruled out. The conclusion is drawn that the mantle material of the Saint Helena plume was supplied to the melting zone beneath the axial rift near the oval rise along a linear permeable zone in the mantle extending at an azimuth of 225° SW. The blocks of mantle material that got to the convecting mantle from the Tristan da Cunha plume at the stage of supercontinent breakup were involved in melting as well. The nontransform offset between the two segments arose on the place of a previously existing transform fracture zone about 5 Ma ago. The nontransform offset developed in the regime of oblique spreading at the progressive propagation of the southern segment to the north. The zone of nontransform offset is characterized by recent volcanic activity. Over the last 2 Ma, spreading of the studied MAR segment was asymmetric, faster in the western direction. The rates of westward and eastward half-spreading in the northern segment are estimated at 1.88 and 1.60 cm/yr, respectively.     

肯尼亚裂谷区地裂缝特征及成因分析

肯尼亚裂谷位于东非大裂谷东支中段,现代构造运动以及火山活动强烈,是当今地学研究的热点地区。裂谷区因其独特的地质构造背景、岩土体特性以及气象水文条件,使得地裂缝灾害较为发育。文章以肯尼亚裂谷地裂缝为研究对象,利用资料收集、野外调查、槽探、钻探和室内土工试验等研究手段,对研究区的地质环境背景、地裂缝平剖面结构特征进行研究。裂谷拉张和火山活动等内动力地质作用是该区域地裂缝形成的控制因素,浅表部松散易潜蚀的土体是地裂缝形成的物质基础,强降雨为地裂缝的形成提供了水力条件,“软硬软”的地层结构为水力侵蚀物质提供了有利的堆积场所。将肯尼亚裂谷区地裂缝的形成演化过程分为3个阶段:孕育阶段、扩展阶段和成灾阶段。     

下辽河大陆裂谷与岩浆活动

下辽河裂谷是我国东部规模巨大的郯庐断裂带的一部分。五十年代以来,地质和地球物理工作者对郯庐断裂带进行过大量的专题和综合性研究^[1-5],取得了可喜的进展。尽管如此,目前对其形成时代、延伸规模、力学机制及活动方式等重要问题,尚存在分歧意见。已有资料表明,发育在华北断块区内的一段,应是郯庐断裂带的主体部分,已确信无疑。该段东界的主干断裂,可能形成于太古代末期(其它三条主干断裂形成时代可能稍晚,但至少在中生代即已存在),构成胶辽断块与冀鲁断块的边界。长期以来,它控制着两侧断块基底的形成和古生界盖层的发育,以及构造格架的布局。     

中-新生代东北和华北的洋陆转换作用

本文对西太平洋的洋-陆转换作用进行探讨。西太平洋洋-陆转换带在中国东部可分为华南、华北-黄海和东北3个区段。东北地区中-新生代洋-陆转换作用涉及古今太平洋板块和蒙古—鄂霍茨克洋板块两方面俯冲作用的影响,产生大面积中基性岩浆和火山活动,从侏罗纪一直延伸到现在。不同于东北和华南地区,华北-黄海有克拉通型的岩石圈,在晚侏罗世—新近纪因为太平洋板块的大角度旋转造成软流圈低黏度物质上涌,和地壳拉张与幔源岩浆的底侵,造成上地壳裂谷型沉积盆地。燕山地区在侏罗纪与东北地区类似,有强烈的软流圈上涌和岩石圈岩石部分熔融,产生强烈岩浆活动。在白垩纪到新生代,因为蒙古—鄂霍茨克洋闭合和太平洋板块大角度旋转,发生沿蒙古—鄂霍茨克洋的转换断层的拉张,产生从南蒙古过锡林浩特的NW向玄武质岩浆和火山带。洋-陆转换带不同区段有不同的动力学作用演化过程,与先期岩石圈的性质、大洋板块俯冲带的分布、方向变化和俯冲持续时间、以及后期俯冲带后撤作用都有密切关系。洋-陆转换作用的统一后果是大陆的增生,但是不同区段大陆增生和物质运动的模式是不一样的。