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1.
Late Paleozoic strata in northeastern China are distributed in a zonal pattern around the old-land on the Jiamusi-Mongolia Block.They are composed of active deposits in the regular distributed tectonic lithofacies zones.This indicates that the late Paleozoic strata belong to continental margin deposits.According to the strong conformability of the sedimentary strata in the same continental margin and distinct differences among the three continental margins,three stratigraphical regions of the Jiamusi-Mongolia Stratigraphical Province are recognized along the northern,southern and eastern margins of the Jiamusi-Mongolia Block,named respectively as Xing’an Stratigraphical Region,Inner Mongolia grass--Songhua River Stratigraphical Region and Baoqing--Hunchun Stratigraphical Region.Due to the characteristics of continental margin deposits and active sediments,the strata can be correlated on the level of formation by the methods of analysing the rock association in the same stratigraphic region.Therefore,some revisions of the lithological formations of the late Paleozoic strata in northeastern China have been made,and a new chart of lithostratigraphic correlation has been proposed.Furthermore,the present stratigraphic framework is setting on the International Stratigraphic Chart on the level of stage,after comprehensive researches to lithostratigraphy,biostratigraphy and chronostratigraphy,especially the conodont biostratigraphy and isotopic ages of volcanic rocks obtained in recent years.  相似文献   

2.
Sedimentary sequence and sediment provenance are important factors when it comes to the studies on marine sedimentation. This paper studies grain size distribution, lithological characteristics, major and rare earth elemental compositions, micropaleontological features and ~(14)C ages in order to examine sedimentary sequence and sediment provenance of the core BH6 drilled at the mouth of the Yellow River in Bohai Sea. According to the grain size and the micropaleontological compositions, 4 sedimentary units have been identified. Unit 1(0–8.08 mbsf) is of the delta sedimentary facies, Unit 2(8.08–12.08 mbsf) is of the neritic shelf facies, Unit 3(12.08–23.85 mbsf) is of near-estuary beach-tidal facies, and Unit 4(23.85 mbsf–) is of the continental lake facies. The deposits from Unit 1 to Unit 3 have been found to be marine strata formed after the Holocene transgression at about 10 ka BP, while Unit 4 is continental lacustrine deposit formed before 10 ka BP. The provenances of core BH6 sediments show properties of the continental crust and vary in different sedimentary periods. For Unit 4 sediments, the source regions are dispersed while the main provenance is not clear, although the parent rock characteristics of a few samples are similar to the Luanhe River sediments. For Unit 3, sediments at 21.1–23.85 mbsf have been mainly transported from the Liaohe River, while sediments above 21.1 mbsf are mainly from the Yellow River and partially from the Liaohe River. For Unit 2, the sediments have been mainly transported from the Yellow River, with a small amount from other rivers. For Unit 1, the provenance is mainly the Yellow River catchment. These results help in better understanding the evolution of the Yellow River Delta.  相似文献   

3.
Clay minerals of 34 sediments collected from the northwestern continental shelf of the East China Sea have been determined by X-ray diffraction analysis. The clay mineral distribution is mainly controlled by the sediment source and the dominant circulation pattern. The predominant clay mineral in our study area is illite comprising more than 67% of the whole clay fraction. The highest concentration of illite (>68%) is found in the southeastern offshore parts beyond the reach of terrigenous input from the Jeju Island. It means that these illites are largely transported by the Kuroshio Current from the South China Sea (SCS). Smectite is highly concentrated in the northwest middle part and in the outer-shelf mud patch. It seems to be due to the high supply of smectite transported from China where fine-grained sediments are discharged from modern and ancient Huanghe (Yellow) River. The relatively high abundant kaolinite is likely derived from the Changjiang (Yangtze) River via the Taiwan Warm Current. In contrast, large amounts of chlorite and high chlorite/kaolinite ratios occur in the northwestern area, reflecting the transportation by the Yellow Sea Coastal Current from the southern Yellow Sea. The discrimination diagrams clearly show that the sediments in the northwestern East China Sea are ultimately sourced from Chinese rivers, especially from the Huanghe River, whereas the sediment in the northeast part might come from the Jeju Island. The muddy sediments of the Changjiang River’s submerged delta have much lower 87Sr/86Sr ratios (0.716 2–0.718 0) than those of the Shandong Peninsular mud wedge (0.721 6–0.724 9), which are supposed to be originated from the Huanghe River, suggesting the distribution pattern of 87Sr/86Sr ratios as a new tracer to discriminate the provenance of shelf sediments in the study area. The 87Sr/86Sr ratios of the outer-shelf muddy sediments ranged from 0.7169 to 0.7216 in a wide range and was between those of the Huanghe River and Changjiang River sediments, suggesting multiple sources of the sediment in the area.  相似文献   

4.
Miocene–Pliocene(22–5 Myr) volcanism and associated seamounts are abundant in the continent-ocean transition(COT) zone in the margin of the north South China Sea(SCS). The petrogenesis of volcanic rocks from these seamounts and regional tectonic evolution of COT zone are poorly known. In this paper, we obtained whole-rock major and trace element compositions and Sr-Nd-Pb isotopic data for these volcanic rocks from the Puyuan and Beipo seamounts within COT zone, in northeastern SCS. Based on the geochemical analyses, the volcanic rocks are classified as alkaline ocean island basalts(OIB) and enriched mid-ocean ridge basalts(E-MORB). The OIBs from the Puyuan seamount are alkaline trachybasalts and tephrites that show enrichment of the light rare earth elements(LREE) relative to heavy rare earth elements(HREE) and more radiogenic Sr-Nd isotopic compositions, and have significant ‘Dupal isotopic anomaly'. In contrast, the E-MORBs from the Beipo seamount are tholeiitic basalts that have less enrichment in LREE and less radiogenic Sr-Nd isotopic compositions than the counterparts from the Puyuan seamount. Petrological and geochemical differences between the OIBs and MORBs from these two seamounts can be explained by different mantle sources and tectonic evolution stages of the COT zone. Syn-spreading OIB type basalts from the Puyuan seamount were derived from an isotopically ‘enriched', and garnet facies-dominated pyroxenitic mantle transferred by the Hainan mantle plume. In contrast, post-spreading E-MORB type basalts from the Beipo seamount are considered to be derived from the melting of isotopically ‘depleted' pyroxenite mantle triggered by lithosphere bending and subsequent post-rifting at the lower continental slope of the northern margin.  相似文献   

5.
Lower Permian formations within the Buqingshan Mountains （A＇nyemaqen ophiolitic zone, eastem sector of the eastern Kunlun） were formed in the following paleogeodynamic environments （from north to south） ： （ 1 ） shelf and slope of a passive continental margin in a marginal sea; （2）partially Permian metamorphic rocks of subduction-accretion complexes and volcanogenic rocks of an ensimatic island arc, of the age limited from above by the Asselian - Sakmarian; and （3） an island are slope and oceanic trench. Subduction-accretion complexes and the island are volcanites are overlain with a sharp angular unconformity by a carbonate-conglomerate sequence, which presents as local molasse of the Early Permian age. Based on fusulinids from the basal limestone, the age of the local molasse is first defined as the Yakhtashian-Bolorian, i.e, Artinskian-Kungurian （？）. The thorough investigations revealed that the initial closure of the eastern Paleotethys within the eastern Kunlun corresponded to the Sakmarian-Yakhtashian （Artinskian） boundary, whereas in the western Paleotethys sector （Northern Pamirs） the closure occurred considerably earlier, prior to the Late Bashkirian. Thus, the idea that the Paleotethys in the eastern Kunlun reached its maximum width in the Permian, is highly questionable. During the Early Permian the A＇nyernaqen branch of the Paleotethys intensely decreased. Beginning from the Bolorian （Kungurian） and up to the end of the Permian this branch represented its relict in the form of a marginal sea depression. It may be suggested that the Paleotethys closure in the A＇nyemaqen took place gradually from the west to the east and covered a long period from the Late Carboniferous to the terminal Early Permian.  相似文献   

6.
As one of the biggest marginal seas in the western Pacific margin, the South China Sea (SCS) experienced continental rifting and seafloor spreading during the Cenozoic. The northern continental margin of the SCS is classified as a passive continental margin. However, its depositional and structural evolution remains controversial, especially in the deep slope area. The lack of data hindered the correlation between continental shelf and oceanic basin, and prevented the establishment of sequence stratigraphic frame of the whole margin. The slope basins in the mid-northern margin of SCS developed in the Cenozoic; the sediments and basin infill recorded the geological history of the continental margin and the SCS spreading. Using multi-channel seismic dataset acquired in three survey cruises during 1987 to 2004, combined with the data of ODP Leg 184 core and industrial wells, we carried out the sequence stratigraphic division and correlation of the Cenozoic in the middle-northern margin of SCS with seismic profiles and sedimentary facies. We interpreted the seismic reflection properties including continuity, amplitude, frequency, reflection terminals, and 15 sequence boundaries of the Cenozoic in the study area, and correlated the well data in geological age. The depositional environment changed from river and lake, shallow bay to open-deep sea, in correspondence to tectonic events of syn-rifting, early drifting, and late drifting stages of basin evolution.  相似文献   

7.
The South Yellow Sea Basin is the main body of the lower Yangtze area in which marine Mesozoic–Paleozoic strata are widely distributed.The latest geophysical data were used to overcome the limitation of previous poor-quality deep data.Meanwhile,the geological characteristics of hydrocarbon reservoirs in the marine Mesozoic–Paleozoic strata in the South Yellow Sea Basin were analyzed by comparing the source rocks and the reservoir and utilizing drilling and outcrop data.It is believed that the South Yellow Sea Basin roughly underwent six evolutionary stages:plate spreading,plate convergence,stable platform development,foreland basin development,faulted basin development,and depression basin development.The South Yellow Sea Basin has characteristics of a composite platform-fault depression geological structure,with a half-graben geological structure and with a ‘sandwich structure' in the vertical direction.Four sets of hydrocarbon source rocks developed – the upper Permian Longtan–Dalong formation,the lower Permian Qixia formation,the lower Silurian Gaojiabian formation,and the lower Cambrian Hetang formation/Mufushan formation,giving the South Yellow Sea Basin relatively good hydrocarbon potential.The carbonate is the main reservoir rock type in the South Yellow Sea area,and there are four carbonate reservoir types:porous dolomitic,reef-bank,weathered crust,and fractured.There are reservoir-forming horizons similar to the typical hydrocarbon reservoirs in the Yangtze land area developed in the South Yellow Sea,and there are three sets of complete source-reservoir-cap rock assemblages developed in the marine strata,with very good hydrocarbon potential.  相似文献   

8.
Lower Permian formations within the Buqingshan Mountains (A'nyemaqen ophiolitic zone, eastern sector of the eastern Kunlun) were formed in the following paleogeodynamic environments (from north to south): (1) shelf and slope of a passive continental margin in a marginal sea; (2) partially Permian metamorphic rocks of subduclion-accretion complexes and volcanogenic rocks of an ensimatic island arc, of the age limited from above by the Asselian - Sakmarian; and (3 ) an island arc slope and oceanic trench. Subduction-accretion complexes and the island arc volcanites are overlain with a sharp angular unconformity by a carbonate-conglomerate sequence, which presents as local molasse of the Early Permian age. Based on fusulinids from the basal limestone, the age of the local molasse is first defined as the Yakhtashian-Bolorian, i.e. Artinskian-Kungurian (?). The thorough investigations revealed that the initial closure of the eastern Paleotethys within the eastern Kunlun corresponded to the Sakmarian-Yakhtashian (Artinskian) boundary, whereas in the western Paleotethys sector (Northern Pamirs) the closure occurred considerably earlier, prior to the Late Bashkirian. Thus, the idea that the Paleotethys in the eastern Kunlun reached its maximum width in the Permian, is highly questionable. During the Early Permian the A'nyemaqen branch of the Paleotethys intensely decreased. Beginning from the Bolorian (Kungurian) and up to the end of the Permian this branch represented its relict in the form of a marginal sea depression. It may be suggested that the Paleotethys closure in the A'nyemaqen took place gradually from the west to the east and covered a long period from the Late Carboniferous to the terminal Early Permian.  相似文献   

9.
Given the conflicts over the proposed formation mechanisms of Xiashu loess, the question of the provenance of sediments comprising the Xiashu loess in the Yangtze River Delta has not been satisfactorily resolved. In this study, the provenance of aeolian sediments of the Yangtze River Delta, China was examined by applying the detrial zircon U–Pb dating technique, Sr–Nd isotopic and trace element compositional analysis. U-Pb dating analysis was conducted on the Xiashu loess at three locations over the Yangtze River Delta, including Huangnishan(HNS) hill, Shengshan(SS) island and the Xuancheng(XC) area. The Xiashu loess and the sediments of the Yangtze River Valley share considerable similarity in their zircon U-Pb age spectra with the same main age peak and comparable age distribution. By contrast, significant differences in the age spectra, existbetween the Xiashu loess and loess deposits of Chinese Loess Plateau(CLP). Coarse grains of the Yangtze River Delta loess may have a proximal material source identical to the sediments from the Yangtze River valley. Sr–Nd isotopic values of the Xiashu loess match those from the northern margin of the Tibetan Plateau. Rare earth element ratios independent of grain size illustrate that the values from loess of the Yangtze River Delta mostly overlap with those of CLP loess. This feature implies that loess from the Yangtze River Delta has a dominant source of distant material similar as the CLP loess. As such, we conclude that multi-proxy analysis of sediments can shed new light on tracing the provenance of aeolian loess in the Yangtze River Delta.  相似文献   

10.
Petroleum geological framework and hydrocarbon potential in the Yellow Sea   总被引：2，自引：0，他引：2  
Sedimentary basins in the Yellow Sea can be grouped tectonically into the North Yellow Sea Basin (NYSB), the northern basin of the South Yellow Sea (SYSNB) and the southern basin of the South Yellow Sea (SYSSB). The NYSB is connected to Anju Basin to the east. The SYSSB extends to Subei Basin to the west. The acoustic basement of basins in the North Yellow Sea and South Yellow Sea is disparate, having different stratigraphic evolution and oil accumulation features, even though they have been under the same stress regime since the Late Triassic. The acoustic basement of the NYSB features China-Korea Platform crystalline rocks, whereas those in the SYSNB and SYSSB are of the Paleozoic Yangtze Platform sedimentary layers or metamorphic rocks. Since the Late Mesozoic terrestrial strata in the eastern of the NYSB (West Korea Bay Basin) were discovered having industrial hydrocarbon accumulation, the oil potential in the Mesozoic strata in the west depression of the basin could be promising, although the petroleum exploration in the South Yellow Sea has made no break-through yet. New deep reflection data and several drilling wells have indicated the source rock of the Mesozoic in the basins of South Yellow Sea, and the Paleozoic platform marine facies in the SYSSB and Central Rise could be the other hosts of oil or natural gas. The Mesozoic hydrocarbon could be found in the Mesozoic of the foredeep basin in the SYSNB that bears potential hydrocarbon in thick Cretaceous strata, and so does the SYSSB where the same petroleum system exists to that of oil-bearing Subei Basin.  相似文献   

11.
Parametamorphic rocks from Arong County in southeastern Inner Mongolia- Daxinganling district are regarded as Proterozoic in age, belonging to the Wolegen Group and composed of volcanoclastic and sand- stone in origin, and have been disputed in tectonic setting. Because of the stability in metamorphism, the rare earth elements indicate the features of their protoliths. The authors integrated the petrologic methods with the geochemical parameters which include ЕREE, ЕLREE/NHREE, δCe, δEu, La/Yb, Sm/Nd, Th/Sc and the standard values of chondrite. The results show that the protoliths of Wolengen Group may be a group of volcanoclastic and continental margin clastic rocks, and their tectonic setting is the continent island arc.  相似文献   

12.
The main task of provenance analysis is to determine the source of sediments and the position of parent rocks.Provenance analysis may find out the relationship between erosion districts and sediment zone,between the uplift and the depression in the process of basin development.The authors use the method of heavy mineral clustering analysis and estimate the provenance direction of Huanghua Depression in the Paleogene Kong 2 Member.Research shows that there were five provenance areas of Kong 2 Member in Kongnan area.They are western(Shenusi),northwestern(Cangzhou),eastern(Ganhuatun),northeastern and southeastern.The main provenance areas were northwestern and western,while the southern provenance could not be ruled out.And these areas are consistent with the known provenance areas.  相似文献   

13.
Jiang  Zuzhou  Sun  Zhilei  Liu  Zhaoqing  Cao  Hong  Geng  Wei  Xu  Haixia  Wang  Lisheng  Wang  Libo 《中国海洋湖沼学报》2019,37(3):998-1009
The hadal zone represents one of the last great frontiers in modern marine science, and deciphering the provenance of sediment that is supplied to these trench settings remains a largely unanswered question. Here, we examine the mineralogical and geochemical composition of a sediment core(core CD-1) that was recovered from the southwestern margin of the Challenger Deep within the Mariana Trench. Major element abundances and rare-earth element patterns from these sediments require inputs from both terrigenous dust and locally sourced volcanic debris. We exploit a two-endmember mixing model to demonstrate that locally sourced volcanic material dominates the sediment supply to the Challenger Deep(averaging ～72%). The remainder, however, is supplied by aeolian dust(averaging ～28%), which is consistent with adjacent studies that utilized Sr-Nd isotopic data. Building on a growing database, we strengthen our understanding of Asian aeolian dust input into the northwestern Pacific, which ultimately improves our appreciation of sedimentation in, and around, the hadal zone.  相似文献   

14.
The main task of provenance analysis is to determine the source of sediments and the position of parent rocks. Provenance analysis may find out the relationship between erosion districts and sediment zone, between the uplift and the depression in the process of basin development. The authors use the method of heavy mineral clustering analysis and estimate the provenance direction of Huanghua Depression in the Paleogene Kong 2 Member. Research shows that there were five provenance areas of Kong 2 Member in Kongnan area. They are western （Shenusi）, northwestern （Cangzhou）, eastern （Ganhuatun）, northeastern and southeast- ern. The main provenance areas were northwestern and western, while the southern provenance could not be ruled out. And these areas are consistent with the known provenance areas.  相似文献   

15.
Saline lakes are useful repositories for paleo-climatic records. In recent years, magnetic properties of saline lake sediments have been widely applied to establish paleo-climatic change. However,the influence factors of magnetic properties in saline lakes have not been fully understood, which complicates the paleoenvironmental interpretation.Here, we present a rock magnetic analyses result of LOP_1 profile(40°26′09″′N, 90°21′23″E) from Lop Nur, a well-known saline lake, located in the eastern Tarim Basin in northwestern China. We combined the particle size, total organic content, and mineral characteristics analysis to assess the influence factors of magnetic properties in Lop Nur and its environmental significance. The results indicate that early diagenesis is the major influence factor on magnetic properties of Lop Nur saline sediments.Authigenic greigite and pyrite are identified within organic-rich sediments, which produce zones with high and low magnetic susceptibilities, respectively.The different authigenic iron sulfide contents in different layers are related to sedimentary environment changes. Sufficient supplies of organic matter and sulphate and low sedimentation rates favour the pyritization process. Moreover, if pyritization was constrained, intermediate greigite formed and was preserved. In oxidizing environments, sediment magnetic properties are consistent with those of source materials from Tarim Basin and are mainly controlled by particle size and hydrodynamic sorting of mainly detrital magnetite is largely unaffected by early diagenesis. Our study demonstrates that magnetic properties can provide a robust approach for studying depositional environment change in saline lake. In addition, the information obtained in this study would also provide insights into the geochemical processes of iron element in saline lakes.  相似文献   

16.
We analyzed heavy metal concentrations in a number of surface sediments and cores from the Qiongzhou Strait and surrounding marine areas.The areas of high concentrations are primarily outside the eastern mouth of the Qiongzhou Strait and on the west side of the Leizhou Peninsula,whereas the areas of low concentrations are located primarily in the eastern Qiongzhou Strait.The maximum Cd,Pb and Zn concentrations in the samples collected in our study do not exceed the official standards for marine sediments,whereas the concentrations of Cr and Cu slightly exceed the standards.Correlations exist between the concentrations of Cu,Pb,Zn,Cr and Cd,and the concentrations of these metals are positively correlated with the mean particle size(φ value),indicating that the finer sediments have adsorbed greater amounts of heavy metal elements than the coarser sediments.An evaluation of the potential environmental risks demonstrates that certain indices of heavy metal pollution and environmental risks are relatively low and may be assigned low risk levels,thereby indicating that,in terms of heavy metals,the marine sedimentary environment in this region is only mildly impacted.Our analysis of the contaminant origins shows that the heavy metals in this region primarily originate in the Pearl River Estuary and that a small amount of them is derived from local runoff.The elevated heavy metal concentrations from the upper sections of the cores started 130 years ago,which indicats that heavy metals in the surface sediments are primarily due to human activities associated with industrialization.  相似文献   

17.
Over the recent three decades,exploration of a large-size Sn-Fe polymetallic ore deposit at the Huanggangliang, the Da Hinggan Mountains, Inner Mongolia, China, has been largely focused on the premise that the mineralization represents epigenetic magmatic hydrothermal ore deposit in genetic connection with the Mesozoic magmatism. The Huanggangliang Sn-Fe polymetallic ore deposits occurred in Permian strata, with siltstone/marble of the Zhesi Formation and spilite/andesite/tuff of the Dashizhai Formation. The characteristics of geological and geochemical data demonstrated that sedimentary hydrothermal mineralization occurred during the basin evolution at the Permian, rather than representing epigenetic magmatic hydrothermal genesis with the following evidences. The ore-bearing skarns are stratiform with underlying metasedimentary rocks and overlying volcanic sedimentary rocks. Sedimentary hydrothermal textures and structures are observed in the stratabound ore-bearing skarn such as bedded-laminated skarn and magnetite ores with small-size folding or soft deformation, synsedimentary breccia of skarn and magnetite ores and concentric shell structure of magnetite ores. So the stratabound ore-bearing skarns associated with magnetite ore and micro-disseminated tin, are peculiar examples of exhalite. The REE contents of the stratabound ore-bearing skarns display ΣLREE-rich (36.91×10-6) but ΣHREE-depletion (6.42×10-6), with positive Eu anomaly (Eu/ Eu 1.28) and negative Ce anomaly (Ce/Ce 0.88), which is totally different from REE pattern of the Huanggang magmatic rocks(with ΣREE 277.73×10-6, ΣLREE 220.24×10-6, ΣHREE 57.49×10-6, Eu/Eu 0.06, Ce/ Ce 1.52), which is comparable with modern sea-floor hydrothermal fluid,sedimentary hydrothermal ore deposit and associated hydrothermal sedimentary rocks. Calcite samples with δ13CPDB from -5.400 ‰ to -4.397 ‰ and δ18OSMOW from 9.095 ‰ to 9.364 ‰ in the stratabound ore-bearing skarns show sedimentary hydrothermal genesis of the Huanggangliang deposit. This proposition is useful not only for interpretation of the genesis of the Huanggangliang large Sn-Fe polymetallic ore deposit but also significant for mineral exploration in the area especially for finding large deposits caused by sedimentary exhalative mineralization processes.  相似文献   

18.
The nature of the crust of the Okinawa Trough is different from that of the continental shelf in the East China Sea. The crust beneath the Trough is in transformation from continental to oceanic and the depth of MOHO in the northern section of the Trough is deeper than in the southern section. Thick sedimentary strata of Neogene and Pleistocene ages are deposited in the Okinawa Trough, and divided into three layers: the upper horizontal layer, the middle layer lightly folded and the lower deformed layer. They were formed in Pleistocene, Pliocene, and Miocene to Paleogene, respectively. The tectonic movement in the southern section is stronger than that in the northern section. Somevolcanic seamounts appear on the bottom of the Trough. On both slopes of the Trough are developed many normal faults and the intrusive igneous rocks. The Okinawa Trough, the back-arc basin,, is an embryonic marginal basin in rifting and spreading. The formation of the Okinawa Trough started in the early Pliocene. The transform  相似文献   

19.
Carbon and nitrogen stable isotopes are useful tracers for distinguishing marine and terrestrial plant sources of sedimentary organic matter(OM),and for identifying OM from different types of plants.By analyzing the carbon and nitrogen stable isotopes of marine and riverine sediments from Bohai Bay and its catchment,we were able to identify the source of OM in these sediments.The stable carbon isotope values of Bohai Bay sediments were between-22.94‰ and-23.90‰,while those of riverine sediments were from-24.45‰ to-32.50‰.Marine algae were the main source of OM in Bohai Bay sediments.However,lacustrine algae were the main source of riverine sediments,not terrestrial OM.The nitrogen isotopes in Bohai Bay sediments decreased in eastward direction,with increasing distance from the coastline,which suggested a higher degree of impact from human activities along the coast.  相似文献   

20.
The Fujian coast Changle-Nanao metamorphism zone rocks are composed of gneiss, schist andhornblendite which had gone through metamorphism of amphilbolite facies, and followed the large-scaleintrusive mass of gneissic granite. The zone was orginally composed of Early Palaeozoiccontinental margin and island arc volcanic and sedimentary rocks. In 180-150 Ma, the zone undermentductile shear deformation and amphibolite facies metamorphism; and in 130-80 Ma, rose rap1dly andco1lided with the Southeastem China continen1al rnargln volonic rocks a10ng the NE trending ductileshear belt. The above geologic setting laid the present Fujian coast tectonic foundation whose formationand evolution are known to be interrlatal with the sueduction and collision of the Taiwan CentralRange.  相似文献   

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