Alluvial Fan-lacustrine Sedimentation and its Tectonic Implications in the Cretaceous Athgarh Gondwana Basin, Orissa, India

The Athgarh Formation is the northernmost extension of the east coast Upper Gondwana sediments of Peninsular India. The formation of the present area is a clastic succession of 700 m thick and was built against an upland scarp along the north and northwestern boundary of the basin marked by an E-W-ENE-WSW boundary fault. A regular variation in the dominant facies types and association of lithofacies from the basin margin to the basin centre reveals deposition of the succession in an alluvial fan environment with the development of proximal, mid and distal fan subenvironments with the distal part of the fan merging into a lake. Several fans coalesced along the basin margin, forming a southeasterly sloping, broad and extensive alluvial plain terminating to a lake in the centre of the basin. Aggradation of fans along the subsiding margin of the basin resulted in the Athgarh succession showing remarkable lateral facies change in the down-dip direction. The proximal fan conglomerates pass into the sandstone-dominated mid-fan deposits, which, in turn, grade into the cyclic sequences of sandstone-mudstone of the distal fan origin. Further downslope, thick sequence of lacustrine shales occur. The faulted boundary condition of the basin and a thick pile of lacustrine sediments at the centre of the basin suggest that tectonism both in the source area and depositional site has played an important role throughout the deposition of the Athgarh succession of the present area. The vertical succession fines upward with the coarse proximal deposits at the base and fine distal deposits at the top, suggesting deposition of the succession during progressive reduction of the source area relief after a single rapid uplift related to a boundary fault movement.The NW-SE trending fault defining the Son-Mahanadi basin of Lower Gondwana sediments are shear zones of great antiquity and these were rejuvenated under neo-tensional stress during Lower Gondwana sedimentation. The E-W-ENE-WSW trending fault of the Athgarh basin, on the other hand, define tensional rupture of much younger date. In the Early Cretaceous period, there was a reversal of palaeoslope in the Athgarh basin (southward slope) with respect to the Son-Mahanadi basin (northward slope). During the phase drifting of the Indian continent and with the evolution of Indian Ocean in the Early Cretaceous period, the tectonic events in the plate interior was manifested by formation of new grabens like the Athgarh graben.     

Stratigraphic correlation between different Gondwana Basins of India

Gondwana Basins of India occur within the suture zones of Precambrian cratonic blocks of Peninsular India along some linear belts. More than 99% of the total coal resource of the country is present within these basins. The basins are demarcated by boundary faults having graben or half-graben geometry.     

大兴安岭南段陆相二叠系-三叠系界线地层序列及其意义:来自锆石U-Pb年代学和生物地层学的证据

陆相二叠纪-三叠纪地层划分与对比研究对认识该时期全球性重大生物和环境事件具有重要意义.以大兴安岭南段阿鲁科尔沁旗坤都地区新发现的下三叠统老龙头组为研究对象, 重点对二叠系-三叠系接触关系开展详细调查研究, 系统采集了界线上下的古生物化石, 对老龙头组火山岩进行了锆石U-Pb同位素测试分析, 并确定了老龙头组与下伏林西组呈平行不整合接触关系, 两者之间存在短暂沉积间断.生物地层显示林西组时代为晚二叠世晚期, 老龙头组古生物匮乏, 可能与二叠系-三叠系之交的生物灭绝事件有关.而老龙头组中3个同位素年龄值分别为251.5±2.2 Ma、249.7±2.5 Ma和249.5±1.8 Ma, 时代指示为早三叠世, 然而二叠系-三叠系界线的准确位置还需进一步研究.大兴安岭南段普遍存在可能与古亚洲洋闭合有关的早三叠世岩浆事件, 古亚洲洋沿着西拉木伦河缝合带发生碰撞闭合, 其闭合时限至少持续至早三叠世, 老龙头组是两大板块拼贴碰撞作用的产物.      

Precambrian crustal evolution of Peninsular India: A 3.0 billion year odyssey

The Precambrian geologic history of Peninsular India covers nearly 3.0 billion years of time. India is presently attached to the Eurasian continent although it remains (for now) a separate plate. It comprises several cratonic nuclei namely, Aravalli–Bundelkhand, Eastern Dharwar, Western Dharwar, Bastar and Singhbhum Cratons along with the Southern Granulite Province. Cratonization of India was polyphase, but a stable configuration between the major elements was largely complete by 2.5 Ga. Each of the major cratons was intruded by various age granitoids, mafic dykes and ultramafic bodies throughout the Proterozoic. The Vindhyan, Chhattisgarh, Cuddapah, Pranhita–Godavari, Indravati, Bhima–Kaladgi, Kurnool and Marwar basins are the major Meso to Neoproterozoic sedimentary repositories. In this paper we review the major tectonic and igneous events that led to the formation of Peninsular India and provide an up to date geochronologic summary of the Precambrian. India is thought to have played a role in a number of supercontinental cycles including (from oldest to youngest) Ur, Columbia, Rodinia, Gondwana and Pangea. This paper gives an overview of the deep history of Peninsular India as an introduction to this special TOIS volume.     

Gondwana coals of Bhutan Himalaya - Occurrence,properties and petrographic characteristics

A narrow belt of highly inclined coal-bearing Gondwana strata occurs in the extreme south-eastern part of Bhutan Himalaya. Recently, a systematic survey was undertaken along this coal belt and coals of three areas were analyzed in detail for the evaluation of their physico-chemical properties and petrographic characteristics.The entire region is in the midst of the Great Himalayan orogenic belt, and the whole stratigraphic sequence underwent several diastrophic movements in the geological past. The massive effects of these orogenies is more pronounced in the coal beds of Gondwana sequence, and due to severe crushing and tectonic shearing these coals became powdery and flaky in nature. Significantly, the coals retained their pre-deformational rank exhibiting typical high-volatile, low-rank, bituminous characters, with mild caking propensities. Also these coals are markedly low in sulphur, phosphorus, chlorine and carbonate content like that of Peninsular Gondwana coals.Petrographic studies of these Bhutan coals revealed a close similarity with the eastern Raniganj coals (Upper Permian) of Peninsular India. The tectonic shearing and crushing of the coals are exhibited by the frequent presence of microfolding, microfaulting, and other compressional structures. However, the coals of all the three areas have shown a consistently low order of reflectance values.This typical retention of pre-deformational low-rank bituminous character is a significant feature of Bhutan coals. It shows that massive orogenic movements were only able to physically crush these coals but could not generate the requisite thermal regime to raise the rank of these coals.     

The Bentong–Raub Suture Zone

It is proposed that the Bentong–Raub Suture Zone represents a segment of the main Devonian to Middle Triassic Palaeo-Tethys ocean, and forms the boundary between the Gondwana-derived Sibumasu and Indochina terranes. Palaeo-Tethyan oceanic ribbon-bedded cherts preserved in the suture zone range in age from Middle Devonian to Middle Permian, and mélange includes chert and limestone clasts that range in age from Lower Carboniferous to Lower Permian. This indicates that the Palaeo-Tethys opened in the Devonian, when Indochina and other Chinese blocks separated from Gondwana, and closed in the Late Triassic (Peninsular Malaysia segment). The suture zone is the result of northwards subduction of the Palaeo-Tethys ocean beneath Indochina in the Late Palaeozoic and the Triassic collision of the Sibumasu terrane with, and the underthrusting of, Indochina. Tectonostratigraphic, palaeobiogeographic and palaeomagnetic data indicate that the Sibumasu Terrane separated from Gondwana in the late Sakmarian, and then drifted rapidly northwards during the Permian–Triassic. During the Permian subduction phase, the East Malaya volcano-plutonic arc, with I-Type granitoids and intermediate to acidic volcanism, was developed on the margin of Indochina. The main structural discontinuity in Peninsular Malaysia occurs between Palaeozoic and Triassic rocks, and orogenic deformation appears to have been initiated in the Upper Permian to Lower Triassic, when Sibumasu began to collide with Indochina. During the Early to Middle Triassic, A-Type subduction and crustal thickening generated the Main Range syn- to post-orogenic granites, which were emplaced in the Late Triassic–Early Jurassic. A foredeep basin developed on the depressed margin of Sibumasu in front of the uplifted accretionary complex in which the Semanggol “Formation” rocks accumulated. The suture zone is covered by a latest Triassic, Jurassic and Cretaceous, mainly continental, red bed overlap sequence.     

Geological history of the Sibumasu Block in Peninsular Thailand: report of a Geologists’ Association Field Meeting in 2007

It is widely accepted that Thailand consists of two principal blocks or terranes, both of Gondwana origin, which collided and fused in the Late Triassic. The western of the two is the Sibumasu Block, and the purpose of this field meeting was to examine Peninsular Thailand where the succession reveals the nature of Sibumasu's Late Palaeozoic rifting from Gondwana in the context of the overall Phanerozoic history of this block. Sedimentary rocks ranging from Cambrian to Miocene crop out in Peninsular Thailand, as well as granite plutons which are aligned in N-S chains, the western chain of Cretaceous–Palaeogene age and those further east of Triassic age. Of particular importance in that history was the NNE-SSW Khlong Marui Fault belt which coincides with the conspicuous bend of the Peninsula; it formed the (present day) eastern boundary of a Late Palaeozoic rift and has been active intermittently since.     

Peninsular India in Gondwana: The tectonothermal evolution of the Southern Granulite Terrain and its Gondwanan counterparts

Peninsular India forms a keystone in Gondwana, linking the East African and Malagasy orogens with Ediacaran–Cambrian orogenic belts in Sri Lanka and the Lützow Holm Bay region of Antarctica with similar aged belts in Mozambique, Malawi and Zambia. Ediacaran–Cambrian metamorphism and deformation in the Southern Granulite Terrane (SGT) reflect the past tectonic setting of this region as the leading vertex of Neoproterozoic India as it collided with Azania, the Congo–Tanzania–Bangweulu Block and Kalahari on one side and the Australia/Mawson continent on the other. The high-grade terranes of southern India are made up of four main tectonic units; from north to south these are a) the Salem Block, b) the Madurai Block, c) the Trivandrum Block, and d) the Nagercoil Block. The Salem Block is essentially the metamorphosed Dharwar craton and is bound to the south by the Palghat-Cauvery shear system — here interpreted as a terrane boundary and the Mozambique Ocean suture. The Madurai Block is interpreted as a continuation of the Antananarivo Block (and overlying Palaeoproterozoic sedimentary sequence — the Itremo Group) of Madagascar and a part of the Neoproterozoic microcontinent Azania. The boundary between this and the Trivandrum Block is the Achankovil Zone, that here is not interpreted as a terrane boundary, but may represent an Ediacaran rift zone reactivated in latest Ediacaran–Cambrian times.     

Gondwana and Cathaysian blocks,palaeotethys sutures and cenozoic tectonics in South-east Asia

The Triassic Indosinian Orogeny followed extinction of the Palaeotethys Ocean resulting in suturing of Gondwana affinity and Cathaysian blocks.The Gondwana affinity Sinoburmalaya block of Peninsular Malaysia, characterized by Carboniferous—Permian mudstones containing glacial dropstones and sparse fauna and flora, is traced extensively into Sumatra. This mudstone facies is flanked on the east by a sandstone-dominated facies and by carbonate localized in the Kinta Valley. The muddy and sandy facies both begin with a basal Carboniferous condensed red bed sequence, which unconformably overlies the older formations of Sinoburmalaya. Both facies also demonstrate a Late Permian conformable transition into overlying limestone. The Cathaysian block of East Malaya is characterized by Late Permian Gigantopteris flora and fusulinid limestones associated with andesitic volcanism. It is similar but not identical to the West Sumatra Carboniferous—Permian block, characterized by Early Permian volcanism, fusulinid limestones and early Cathaysian Jambi flora.The South to SSE trending central Peninsular Malaysian Triassic orogenic belt swings south-east from Singapore to Bangka, then east to Billiton. The Palaeotethys suture (Bentong—Raub Line) forms the western margin of this belt and is therefore unlikely to continue south along the Palaeogene Bengkalis Graben, which transects the north-west—south-east orogenic fabric of Sumatra.The oroclinal bending of the Indosinian Orogen, from a north-west—south-east grain in Sumatra to a northerly grain through Peninsular Malaysia, is attributed to the Palaeocene collision of India and its subsequent indentation into Eurasia. The bending was accomplished by clockwise rotation and right-lateral shear parallel to the orogenic grain. The Mesozoic Palaeotethyan sutures were transformed into Palaeocene and younger shear zones. The outer zones of the orocline experienced pull apart tectonics (Andaman Sea and Sumatra basins) while the inner part (East Malaya to Billiton), being compressional, lacks Cenozoic basins.     

Study on a Terrestrial Permian—Triassic Boundary Section—Zhejue Section, Weining County,Guizhou Province, China

The Zhejue Section is an excellent terrestrial permian-Triassic boundary (TPTB) section not only for its convenient accessibility and good outcrop, but also for its abundant fossils. In addition, there are two claystone beds that were formed by events across the Permian-Triassic boundary (PTB) at this section. The claystones provide a bridge for high-resolution correlation between marine and terrestrial PTBs. Another advantage is that the PTB at the Zhejue Section can be correlated with that of littoral and neritic facies by tracing estwards. Synthesized stratigraphic studies, including biostratigraphy, eventostratigraphy )susceptibilities and carbon isotopes across the TPTB, and microspherules found in the boundary claystones) and sequence stratigraphy, are carried out at this section.     

陆相二叠系-三叠系界线研究进展

着重介绍了几个目前陆相二叠系—三叠系界线（TPTB）研究的重点剖面及其生物地层学研究进展；分析了陆相二叠系—三叠系界线综合地层学研究现状，包括生物地层学、事件地层学、同位素年代学、磁性地层学和层序地层学等；剖析了陆相二叠系-三叠系界线地层学研究中存在的问题及进一步的研究方向。生物地层方面，陆相二叠系-三叠系界线附近存在晚二叠世与早三叠世生物混生的层位，其中不同类别生物的时间界线常不一致，又由于陆相界线地层中含脊椎动物化石的层位一般较少，以脊椎动物化石（Lystrosaurus）为标准的精确界线常不确定，因而需重新寻找并确定陆相三叠系底界的标准化石。事件地层标志可能会成为连结海、陆相二叠系-三叠系界线地层高精度对比的纽带。     

三叠纪年代地层与生物复苏

二叠纪末大灭绝之后，三叠纪初残存期和复苏期生态系研究成为当今热点。这也是2005年5月在安徽巢湖召开的“三叠纪年代地层与生物复苏国际学术会议”上的主导论题。逐一介绍了会议学术报告的主题内容，以期提炼相关领域的学术关键和学科发展趋向。学术主题之一是早三叠世年代地层格架，尤其是印度阶―奥伦尼克阶界线层型；第二是二叠纪―三叠纪之交灭绝和环境事件的表现形式和过程；第三是二叠纪―三叠纪之交及早三叠世微生物岩及其代表的特殊生态系；第四是灭绝事件后三叠纪初一些关键生物类别的演变历程；第五是中生代初生态系复苏过程和型式；第六是早三叠世生物迟滞复苏的原因。     

North Gondwana origin for exotic Variscan rocks in the Rhenohercynian zone of Germany

Continental margin sediments of an exotic nature, which have been thrust over the Rhenohercynian zone of Central Germany, occur mainly in olistostromes of Lower Carboniferous age. A stratigraphy compiled from the exotic rocks reflects the wide spectrum of continental shelf and adjacent basinal facies that existed at least from the Early Ordovician to the Early Carboniferous. Facies and faunal relationships are comparable with those in the Palaeozoic of the western Mediterranean region, Saxothuringia (south-east Germany) and the Barrandian area (Czech Republic), which suggests deposition at the northern margin of the Gondwana Palaeozoic supercontinent. Among the exotic rocks, a Middle Devonian to Early Carboniferous facies, referred to as Flinzkalk, contains sediments showing characteristics of contourites. They may have originated from reworked turbidites, formed under a current which flowed parallel to the North Gondwana margin, similar to the Gulf Stream flowing along eastern North America today.     

Correlation of the Early Permian faunas of Gondwana : Implications for the Gondwanan Carboniferous‐Permian boundary

In an attempt to elucidate their ages, the often incomplete and poorly known early Permian marine faunas and sequences of India, Tibet, Pakistan, Afghanistan, Iran and Oman are compared with those of the Perth, Carnarvon and Canning Basins of Western Australia, where faunas are documented and in sequence, and stratigraphic relationships between units are clear. This comparison indicates that the faunas discussed are Latest Asselian or younger in age, and that most of the underlying glacial beds are probably Early Permian (Asselian) in age. By implication, the Permo‐Carboniferous boundary for Gondwana is considered to lie at or near the base of Unit II/Stage 2 and equivalent palynomorph zones throughout Gondwana.     

Stratigraphy and palaeoenvironmental evolution of the mid- to upper Palaeozoic succession in Northwest Peninsular Malaysia

The stratigraphy of the Devonian to Permian succession in Northwest Peninsular Malaysia is revised. The Timah Tasoh Formation consists of black mudstone containing graptolites and tentaculitids indicating a Pragian or earliest Emsian age. The Sanai Limestone overlies the Timah Tasoh Formation at Sanai Hill B and contains conodonts indicating a Late Devonian (Frasnian to possibly early Famennian) age. In other places, Late Tournaisian chert of the Telaga Jatoh Formation overlies the Timah Tasoh Formation. The overlying Kubang Pasu Formation is predominantly composed of mudstone and sandstone, and can be divided into 3 subunits, from oldest to youngest: (1) Chepor Member; (2) Undifferentiated Kubang Pasu Formation; (3) Uppermost Kubang Pasu Formation. The ammonoid Praedaraelites tuntungensis sp. nov. is reported and described from the Chepor Member of Bukit Tuntung, Pauh. The genus indicates a Late Viséan age for part of the subunit. Dropstones and diamictites from the Chepor Member indicate a glacial marine depositional environment. The Carbo-Permian, undifferentiated Kubang Pasu Formation consists of similar interbedded mudstone and sandstone. The uppermost Kubang Pasu Formation of Kungurian age consists of coarsening upward cycles of clastics, representing a shallow marine, wave- and storm-influenced shoreline. The Permian Chuping Limestone also represents shallow marine, wave- and storm-influenced deposits. A Mid-Palaeozoic Unconformity separating Early–Late Devonian rocks from overlying Late Devonian–Carboniferous deposits probably marks initiation of rifting on Sibumasu, which eventually led to the separation of Sibumasu from Australian Gondwana during the late Sakmarian (Early Permian).     

Evidence of Insect-plant Interactions From the Upper Gondwana Sequence (Lower Cretaceous) in the Rajmahal Basin, India

The present paper reports significant evidence of insect-plant interactions in the Upper Gondwana sequence (Early Cretaceous) from various localities of the Rajmahal Formation in the Rajmahal Basin of Jharkhand State, India. This evidence is among the first Early Cretaceous evidence of phytophagy and is recognised by various types of feeding traces namely continuous marginal, discontinuous marginal and non-marginal. These traces may indicate herbivory of pinnate leaves ofPtilophyllurn (Bennettitales) and these herbivores may have assisted the plants in pollination. Additional evidence for a plant-insect relationship is on the lamina o f Phyllopteroides pinnae (Osmundaceae) which was used for ovipostional sites containing oval egg impressions that occur along the veins in the leaf lamina. Further, the evidence of insect galls recognised on a Nipaniophyllurn (Pentoxylales) leaf surface indicates that the lamina was used as a shelter habitat for insect larvae. These galls show some similarity with extinct leaf galls reported on Glossopteris (Glossopteridales) leaves recorded from the Permian of Kashmir Himalaya, India as well as on galls on Sophora (Fabaceae) and Eomangferophyllum (Anacardiaceae) leaves from the Neogene flora of India. Similar spherical leaf galls are induced by Diptera (Cecidomyiidae) and Hymenoptera (Pteromalidae) on leaves of modern Anadenanthera peregrina from Brazil. The present findings from the Upper Gondwana Sequence of India reveals that these types of insect-plant relationships existed during the Gondwana time and continued up to the recent, perhaps having a role in the co-evolution of present flora and fauna.     

The Phuket-Slate Belt terrane: tectonic evolution and strike-slip emplacement of a major terrane on the Sundaland margin of Thailand and Myanmar

The Phuket-Slate Belt terrane can be traced for 1700 km from Phuket to Mandalay, and has a distinct stratigraphy and tectonic history. It is characterized by a very thick Carboniferous-Lower Permian succession which includes diamictites interpreted as glacio-marine rift-infill deposited when the Sibumasu block separated from Gondwana. It was emplaced in the Late Cretaceous-Palaeogene by dextral strike-slip movement on a fault system which includes the Khlong Marui and Panlaung Faults. Southwards the Khlong Marui bounding-fault and its close associate, the Ranong Fault, are postulated to extend to Sumatra where they align with the restored proto-Indian Ocean location of the India–Australia transform at the time that both were undergoing dextral displacement and Greater India was moving toward its collision with Eurasia. It is suggested that emplacement of the Phuket-Slate Belt terrane was the result of its coupling with the north-going India plate, resulting in up to about 450 km of dextral shift on the terrane's bounding fault system. Post-emplacement sinistral movement on the cross-cutting Mae Ping and Three Pagodas Faults offset the terrane boundary resulting in its present outline.     

青海南部二叠纪类生物古地理区系

冈瓦纳与欧亚大陆间的昌都地块构造属性存在争议,解决问题的关键是生物古地理区系判别.青海南部二叠纪类化 石群的研究表明昌都地块该生物群一直表现为暖水的特提斯型,与华南地区始终表现出更多的相似性,其生物古地理归属应 为特提斯大区华夏-特提斯区华南亚区.昌都地块南界龙木错-双湖-澜沧江缝合带在早二叠世为划分青藏高原暖水型特提 斯区的南界,不仅是华南亚区与藏北冷暖混合亚区的分界线,也是特提斯大区与冈瓦纳大区的分界线.中二叠世以后该带不再 构成大区界线,但在确定次一级分区界线上仍是一个很好的划分标志;北界金沙江缝合带二叠纪两侧生物群表现出一致性, 未形成浅海底栖生物自由迁移的障碍,不具有生物古地理分区意义.      

Tectonic evolution of the Malay Peninsula

The Malay Peninsula is characterised by three north–south belts, the Western, Central, and Eastern belts based on distinct differences in stratigraphy, structure, magmatism, geophysical signatures and geological evolution. The Western Belt forms part of the Sibumasu Terrane, derived from the NW Australian Gondwana margin in the late Early Permian. The Central and Eastern Belts represent the Sukhothai Arc constructed in the Late Carboniferous–Early Permian on the margin of the Indochina Block (derived from the Gondwana margin in the Early Devonian). This arc was then separated from Indochina by back-arc spreading in the Permian. The Bentong-Raub suture zone forms the boundary between the Sibumasu Terrane (Western Belt) and Sukhothai Arc (Central and Eastern Belts) and preserves remnants of the Devonian–Permian main Palaeo-Tethys ocean basin destroyed by subduction beneath the Indochina Block/Sukhothai Arc, which produced the Permian–Triassic andesitic volcanism and I-Type granitoids observed in the Central and Eastern Belts of the Malay Peninsula. The collision between Sibumasu and the Sukhothai Arc began in Early Triassic times and was completed by the Late Triassic. Triassic cherts, turbidites and conglomerates of the Semanggol “Formation” were deposited in a fore-deep basin constructed on the leading edge of Sibumasu and the uplifted accretionary complex. Collisional crustal thickening, coupled with slab break off and rising hot asthenosphere produced the Main Range Late Triassic-earliest Jurassic S-Type granitoids that intrude the Western Belt and Bentong-Raub suture zone. The Sukhothai back-arc basin opened in the Early Permian and collapsed and closed in the Middle–Late Triassic. Marine sedimentation ceased in the Late Triassic in the Malay Peninsula due to tectonic and isostatic uplift, and Jurassic–Cretaceous continental red beds form a cover sequence. A significant Late Cretaceous tectono-thermal event affected the Peninsula with major faulting, granitoid intrusion and re-setting of palaeomagnetic signatures.     

从板缘碰撞到陆内造山:华南东南缘早古生代造山作用演化

华南的广西运动被认为是发生在早古生代的陆内造山作用,然而触发陆内变形的地球动力学机制仍然不清.广西运动形成了泥盆系与下伏岩石之间广泛的不整合面以及分布在局部地区的下古生界内部的多个不整合面.广西运动期间的构造热事件和古生物响应时间在460~380 Ma,时间上对应于奥陶系和泥盆系之间的多个不整合,而分布在华南南缘的寒武系和奥陶系之间的不整合面（郁南运动）仅与少量的530~480 Ma之间的变质事件相当,但是却同步于广泛分布在东冈瓦纳北缘的造山事件.华南南部寒武系-奥陶系不整合面上下的碎屑锆石年代学研究表明,早古生代华南与印度北缘相连,而三亚地块在寒武纪是澳大利亚西缘的一部分,直到奥陶纪才与华南拼合,同步于冈瓦纳最终的聚合.郁南运动之后,华夏板块处于冈瓦纳内部,来自冈瓦纳东缘造山作用的应力向大陆内部传播,在具有弱流变学性质的南华盆地聚集,导致盆地构造反转,触发了广西运动.早古生代的华南经历了从板缘碰撞（郁南运动）到陆内造山（广西运动）的演化过程.