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《Bulletin of Mineralogy, Petrology and Geochemistry》
JOPC 2023 Vol.25 Number 3
2023, Vol.25 Num.3
Online: 2023-06-01
REVIEW
LITHOFACIES PALAEOGEOGRAPHY AND SEDIMENTOLOGY
PALAEOGEOGRAPHY AND MINERAL RESOURCES
HUMAN HISTORY PALAEOGEOGRAPHY
0
2023 Vol. 25 (3): 0-Ⅰ [
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REVIEW
511
WU Yasheng
Classification of biolith(biogenic rocks)
Bioliths are the main research object of the new interdisciplinary biopetrology,are rocks formed by biological processes,including reef rocks,rocks composed of non-reef-building organisms and micrite,and rocks formed by microbial processes. Previously,reef rocks and microbialites were studied separately and not included in the same discipline. The classical classification system of reef rocks and microbialites only includes a part of reef rocks and microbialites,and some biolith types are not recognized and included. The incomplete classification of bioliths limited the research of bioliths. In this paper,a unified classification system of bioliths including reef rocks,non-reef-building skeletal carbonates,microbialites and other microbiogenic rocks is proposed. The new basic bioliths include biomicrite,microlithite,microbialite,microallolite,micromicrite,framelite,crustolite,wrapolite,and filalite. This classification of bioliths into 24 basic rock types in 4 levels may facilitate the study of bioliths. The author also modified and improved the definition of some rocks such as framestone and discussed some problems in the study of biolith.
2023 Vol. 25 (3): 511-524 [
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525
FANG Weixuan
Hydrothermal sedimentary lithofacies and their tectono-palaeogeography
Hydrothermal sedimentary facies can be formed in rifted basins,mid-oceanic ridges,arc-basin system,as well as epeiric basins and intracontinental lacustrine basins. According to diagenetic and metallogenic modes,rock associations,and geochemical dynamic classifications,hydrothermal sedimentary lithofacies may be classified into hydrothermal syngenetic sedimentary lithofacies,hydrothermal quasi-syngenetic metasomatism lithofacies,hydrothermal syngenetic altered lithofacies,lithofacies of hydrothermal-blasting to hydraulic fracturing breccias,lithofacies of thermal brine quasi-syngenetic infiltration-metasomatism,and lithofacies of crytoexplosive to hydraulic fracturing breccias by hydrothermal fluids related to hydrothermal plume,including 17 types of tectonic lithofacies. All of them are of basic to establishment of independent tectonic mapping elements. The root,vent,center,proximate,and distal facies of the hrdrothermal fluid system have obvious tectonic lithofacies zonation and distribution in basins. However,all of them experienced deformations such as cataclastic rock facies,mylonite facies,and facies of the altered rocks related to thermal fluid reworking,overprinting,and reconstruction in intrcontinental orogens. After studies on deformation history and deformation-sieving of tectonic lithofacies,their tectono-palaeogeography units can be better understood. It may further help us to improve detecting buried tectonic lithofacies and mineral resource predication.
2023 Vol. 25 (3): 525-553 [
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LITHOFACIES PALAEOGEOGRAPHY AND SEDIMENTOLOGY
554
LIANG Jiwei, ZONG Hao, FENG Kunming, CHANG Xiaobin, LI Hanlin, FENG Zhenwei, ZHENG Meng, CHEN Xin, LI Wenhou
Characteristics of deep water deposits of the Ordovician Pingliang Formation in Ordos Basin
Deep-water deposits are well developed in the Early Paleozoic Pingliang Formation of the Ordos Basin. The investigation on the sedimentary system types and characteristics of the Pingliang Formation is not only helpful to understand the paleogeographic pattern and tectonic characteristics,but also has an important implication for oil and gas exploration. Based on the field survey and indoor comprehensive study of the Pingliang Formation and its contemporaneous strata in the southwest margin of the basin,we have systematically studied the Pingliang Formation in the Ordos Basin from the perspectives of stratigraphic spatial distribution,rock types,structure and texture,sedimentary facies,organic geochemical characteristics,
etc.
Our work indicated that there are deep-water autochthonous deposits,traction current deposits,gravity current deposits,pyroclastic rocks and seismites deposits in the Pingliang Formation,forming a sedimentary assemblage of front platform slope and deep-water basin facies. Combined the tectonic setting with sedimentary facies assemblage,the deep-water sedimentary model of the Pingliang Formation was established. The water depth of the Pingliang Formation was shallow at the initial stage of sedimentation with undeveloped contour current deposits,while the gravity flow deposits were dominant. Towards to the middle and late developed period,the gravity flow weakened with the deepening of water level,which leaded to rework of the preexisting deposits by contour currents. In addition,the deep-water deposits of the Pingliang Formation are conducive to oil and gas accumulation. Based on stratum thickness,rock type,sedimentary facies,organic matter type and content,as well as thermal evolution degree,favorable oil and gas exploration areas in the Pingliang Formation are selected in this research,which are mainly distributed in south of Wuhai,the east of Shizuishan-Helan and the west of Otog Qianqi. The area is about ten thousand square kilometers and is banded distributed in north-south direction. Finally,it is found that the key area of exploration is mainly distributed in part of the Tianhuan depression,east of Helan.
2023 Vol. 25 (3): 554-572 [
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573
WANG Ji, WANG Feng, ZHAO Weibo, HU Jianling, WU Jingyi, XIAO Yunxiao, CHEN Hongde, LIU Lei, WANG Zhiwei, ZHU Shuyue
Lithofacies types and sedimentary models of the Upper Carboniferous Yanghugou Formation in western margin of Ordos Basin
There are much unknown about the Yanghugou Formation in the Qilian sea area in the western Ordos Basin,due to greatly varied strata thickness,diverse lithofacies associations,unclear sedimentary evolution sequences,and complex sedimentary model. Based on the detailed observation of 12 field sections and 28 drilling cores in the Yanghugou Formation in the middle and eastern part of the Qilian sea area,and combined with thin section petrological characteristics,grain size analysis,fossil remains,paleo-flow analysis,geochemistry and well logging data analysis,the lithofacies,lithofacies association characteristics as well as the sedimentary facies and evolution process of the Yanghugou Formation are systematically studied. This research shows that there are 18 lithofacies types and 8 lithofacies associations developed in the Yanghugou Formation in the Qilian sea area,western Ordos Basin,which respectively reflect the delta plain distributary channel,tide dominated delta front subaqueous distributary channel,estuary-tidal flat(tidal channel,tidal sand bar),tidal flat(sand flat,mixed flat and mudflat),barrier coast(barrier island,lagoon),barrier-open shore and shelf sedimentary characteristics. During the Yanghugou Formation depositional period,the central paleo-uplift spread from south to north across the western margin of the basin,dividing the basin into Qilian Sea and the North China Sea,and the western part of the basin is generally located in the Qilian Sea. It was a transitional continental-ocean sedimentary environment,and experienced a cycle of water deepening and then shoaling. During the deposition of the 3
rd
member of the Yanghugou Formation,the eastern Ordos basin was still the ancient uplift exposed to denudation,only limited deposition occurred in western basin margin. In the northern part of the study area,the water depth is shallower,and there were tidal delta-tidal flat-barrier island deposits in the Wuda-AlashanZuoqi area,while there are relatively deep water bodies in the central and southern part of the study area,and barrier island-shelf deposits were mainly developed. During the sedimentary period of the 2
nd
Member of the Yanghe Formation,due to the barrier of the central paleo-uplift,the east and west sea areas had not communicated,but the sedimentary range and depth of water increased significantly compared with the early period,with strong tidal influences and limited fluvial influences. In the northern Wuda area and the southern Jingyuan area of the study area,estuarine and tidal flat deposits were dominant,and the central area had the deepest water and developed shelf deposits. During the sedimentary period of the 1
st
Member of the Yang Formation,due to the transgression of the Qilian Sea to the east and the shrunk of the central paleo-uplift,the east and west seas communicated with each other. Consequently,the depositional area expanded,and the water body became shallower in general. In the western part of the study area,the water body was slightly deep and delta-barrier island deposits were developed,while in the eastern part the water body was shallower and tidal flat deposits were developed.
2023 Vol. 25 (3): 573-597 [
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598
WANG Lan, LI Wenhou, LIU Qun, WANG Daxing, ZHANG Mengbo, BAI Bin
Lithofacies characteristics and sedimentary environment of Chang 7 black shale in the Yanchang Formation,Ordos Basin
Chang 7 black shale of the Yanchang Formation,Ordos Basin,has a wide distribution area,large thickness and high organic matter content,which has a broad shale oil exploration prospect. Based on the analysis of a large number of core,thin section and geochemical data,the lithofacies types,geological characteristics and distribution laws of Chang 7 black shale are analyzed,and the palaeoenvironment and shale genetic mechanism during its formation period are studied by using trace element indicators. According to the classification standard of “organic matter abundance-rock mineral composition-sedimentary structure”,Chang 7 is divided into three types of lithofacies,in which the bottom of Chang 7
3
is developed with very rich organic matter laminated shale,and Chang 7
2
is transformed into organic matter rich laminated clay/silty shale,and Chang 7
1
is developed with poor organic matter massive silty mudstone. From Chong 7
3
to Chang 7
1
,as the lake basin shrinks and the delta advances,the content of clay minerals,organic matter and pyrite and the development of laminae gradually decrease. The subtropical warm and humid climate and long-term stable deep-water lake environment create conditions for the large-scale development of algae. The trace element study shows that Chang 7
3
extremely rich organic shale was formed in a strong reducing environment with extremely high productivity in the lake basin,oxygen deficiency and even sulfurization in the water body,and was affected by volcanic activity and lake bottom hydrothermal solution. Therefore,it is rich in collophanite,Ni,Cu,Mo and other nutrients,and is a rare uranium rich shale in China. Based on the comprehensive analysis of palaeogeomorphology,climate and hydrological conditions,it is considered that the genetic mechanism of the Chang 7 black shale is the water stratification model of the depressed lake basin under the strong tectonic movement of volcanic and hydrothermal activities.
2023 Vol. 25 (3): 598-613 [
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614
CHEN Lei, TAN Xiucheng, ZHENG Jian, CHEN Xin, YANG Yang, XIONG Min, WANG Gaoxiang, JI Yubing
Shallow-water onlap sedimentary mode of black organic-rich shale in the Longmaxi Formation,Upper Yangtze area
Fine-grained sedimentation determines the material basis of shale and plays an important role in the formation of high-quality shale. Based on the comprehensive analysis of drilling cores,outcrops,thin sections and seismic data,the sedimentary mode of the black shale from the Longmaxi Formation in the Upper Yangtze area was studied. The results show that(1)siltstone interbedded with shale,bioturbation,cross bedding,wavy laminae,graded laminae,orientation of mud gravel and basal erosion occurred in the black organic-rich shale of the Longmaxi Formation,which reveals obvious shallow water sedimentary characteristics. (2)The reverse graded deposition sequence of shale-silty shale-siltstone under wave action is developed in the black shale,reflecting that wave action has an important influence on the formation of black shale in the Longmaxi Formation. (3)The storm has a certain impact on the formation of black shale in the Longmaxi Formation,which shows the normal graded deposition sequence of siltstone to black shale formed on the irregular erosion surface. (4)A comparison of the seismic profile and regional stratigraphic well profile shows that the black shale of the Longmaxi Formation presents obvious onlap to the margin of the paleo-uplift with the rise in sea level. These results reflect that the black shale of the Longmaxi Formation in the Upper Yangtze area formed in limited shallow water,which is vulnerable to waves and storms. The continuous onlap of shale occurred with the rise in sea level. The shallow-water onlap sedimentary mode of the organic-rich shale in the Longmaxi Formation has significant guidance for the exploration of organic-rich shale in the Upper Yangtze area.
2023 Vol. 25 (3): 614-627 [
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628
JIAO Guohua, ZHANG Weiping, XIE Lihua, WANG Jun, ZHOU Jinke, WANG Yunhai
Depositional systems and their controlling factors of the Lower Jurassic Sangonghe Formation in southern Junggar Basin
The Sangonghe Formation is the main production unit of the southern Junggar Basin,but the provenance,sedimentary facies,and their controlling factors remain poorly resolved. In this paper,the 4th sequence-stratigraphic framework of the Sangonghe Formation was investigated based on outcrops,well logging,cores,and seismic data. The results suggest that the provenance change,the palaeogeomorphic evolution,the tectonic and palaeoclimate conditions controlled sedimentary patterns and filling process in the southern Junggar Basin during the Early Jurassic. The Junggar Basin formed under a relatively stable tectonic environment and relatively humid palaeoclimate in the Early Jurassic. There are two sedimentary facies and five sedimentary systems in the central and the eastern of the southern Junggar that was a wide and gentle catchment area in Early Jurassic. One facies is shoal-water baided-river delta,which is divided into four sedimentary systems,respectively,from the Zaire Mountain to the west of Junggar Basin,Halarat Mountain to the northwest of Junggar Basin,Kelamili Mountain to the east of Junggar Basin and Tanshan Mountain to the south of Junggar Basin. The other facies is shoal-water fan delta from the Tianshan Mountain to the south of Junggar Basin. There are two sedimentary facies and two sedimentary systems in the western of the southern Junggar Basin that was a small and sharp catchment area in the Early Jurassic. One faices is Gilbertian shallow-water fan delta from the Tianshan Mountain to the south of Junggar Basin,and the other is shoal-water braided-river delta from the Zaire Mountain to the western Junggar Basin. Controlled by palaeoclimate and depositional base level,the interval 1 of Member 2 of Lower Jurassic Sanggonghe Formation is a lowstand system tract,and the depositional base level is low. The deltas extended further forward,and resulted in sandbodies distributed widely and fining forward. The interval 2 of Member 2 of Lower Jurassic Sanggonghe Formation is a transgressive system tract,and the Member 1 of Lower Jurassic Sanggonghe Formation is a highstand system tract. The range of their deltas distributed smaller than those of the submember 2. Shore-shallow lacustrine deposits were dominant in the Member 1,which were the early sediment of a highstand system tract.
2023 Vol. 25 (3): 628-647 [
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648
LI Zhaoyu, LI Yongxiang, LI Wenhou, ZHANG Yunxiang, XIE Kun, ZHANG Qian, LI Zhaoyang
Sedimentary facies and paleoenvironmental evolution of the Cenozoic Lanzhou Basin,northeastern Tibetan Plateau
As one of the earliest Cenozoic sedimentary basins located on the northeastern margin of the Tibetan Plateau, the Lanzhou Basin is an ideal area to study the plateau uplift and paleoclimatic evolution. Based on the outcrop observations, lithological characteristics, paleontological fossils and sedimentary geochemistry, comprehensive studies were carried out on the sedimentary evolution of the Lanzhou Basin during the Eocene-Middle Miocene. The results show that the orange or brownish red sandstone of the Eocene Xiliugou Formation represents the eolian desert deposits, rather than the fan delta or the fluvio-lacustrine facies. After the deposition of the Xiliugou Formation, fluvial-delta-lacustrine facies occurred in the basin. The Yehucheng sedimentary period was characterized by a hot dry climate, forming inshore shallow lake deposits, together with small-scale delta. From the late Early Oligocene (i.e., the early stage of the Xianshuihe Period), delta deposition developed, and then the water body gradually expanded. Until the Late Oligocene, the inshore shallow lake deposits developed, and the paleoenvironment changed from the semihumid-semiarid open woodlands and shrub to arid shrub and grassland. At the beginning of the Early Miocene (i.e., the middle stage of the Xianshuihe Period), the delta plain deposits developed, and then rapidly evolved into the delta front and shallow lacustrine environments, representing the final expansion of the Cenozoic lake in the Lanzhou Basin dominated by the semi-dry climate. During the Middle Miocene (i.e., the late stage of the Xianshuihe Period), the lake basin began to shrink and gradually disappeared, which was replaced by the fluvial sedimentary system, and the small-scale bottomlands were only locally distributed. The paleoenvironment was predominated by semiarid shrub and grasslands.
2023 Vol. 25 (3): 648-670 [
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PALAEOGEOGRAPHY AND MINERAL RESOURCES
671
LIU Yongle, LI Wen, ZHAO Jingchun, LI Youlu, XIA Youhe, ZHANG Daming, DONG Zhiguo, LI Wenjun, ZHANG Lianchang
Sedimentary facies and depositional environment of Santonggoubei manganese deposit in eastern Kunlun of Qinghai Province
The Santonggoubei manganese deposit is a recently found marine sedimentary manganese deposit in south tectonic zone of the eastern Kunlun orogen. Preliminary studies indicate that this manganese deposit is hosted in siliceous and fine-grained clastic rocks of the Ordovician-Silurian Nachitai Group. To date,the Santonggoubei deposit is only moderately studied with respect to sedimentary facies and depositional environment. Based on field investigations of regional geology and deposit geology,combined with sedimentological measurement of outcrop sections,petrographic observations and geochemical analysis,the authors suggest that the Santonggoubei manganese deposit formed on a passive continental margin. The main ore belts(from Ⅰ to Ⅲ)formed in the marginal facies of the southern deep-water basin,which was characterized by siliceous rocks,siliceous mudstone,and carbonaceous mudstone,intercalated with argillaceous siltstone;the marginal facies was in contact with slope sandstone and shelf sandstone-siltstone. The Ⅳ-Ⅴ mineralization belt was distributed in the restricted depression of the shelf facies,which was characterized by argillaceous siltstone,siliceous mudstone,and siliceous rocks. The Mn ore-bearing succession was overlain by shelf siltstone-fine sandstone and carbonate rocks. Overall,the palaeogeographic environments of the Santonggoubei manganese deposit were marine shelf depression and the margin of the deep-water basin. Geochemical analysis demonstrates that the formation of the main ore belt was closely related to the oxic-rich conditions of the basin waters. The precipitation mechanism of manganese is related to the episodic intrusions of shallow,oxygen-rich waters into the edge of deep-water basin.
2023 Vol. 25 (3): 671-683 [
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684
BI Mingwei, SUN Jiaopeng, CHEN Shiyue, ZHOU Zhaohua, ZHANG Manlang, QIAN Aihua
Multiscale description and controlling factors analyses of fluvial tight reservoir: a case study on the 8th Member of Lower Shihezi Formation in Sulige gas field, Ordos Basin
In this study,we carries out a comprehensive work of outcrop section observation,microscopic petrology investigation and quantitatively analysis of microscopic pore structure to reveal the fluvial reservoir characteristics of the 8th Member of the Lower Shihezi Formation of Su6 Area,Sulige Gas Field. Sand body structure characteristics,sandstone types,pore types,microscopic pore structure characteristics are detailed analyzed to indicate the controlling factors of effective fluvial tight sand reservoir. Our work demonstrates that the sand body of channel bar and point bar are the flooding event deposition and are medium-coarse grained lithic quartzarenite and litharenite. On the contrary,the channel fill microfacies sand body is the normal river flow period deposition,the associated sandstone is characterized by fine grained(feldspathic)litharenite and lower structure maturity. The medium-coarse grained sandstones have a large proportion of dissolved and interconnected pores with larger radius effective pore-throat. The pore types of fine-grained sandstones are mainly clay minerals intercrystalline pores,and the pore-throat radius is much smaller. Densification modes of fluvial reservoir can be divided into three types,such as densification of medium-coarse grained lithic quartzarenite by strong siliceous cementation and medium to strong compaction,densification of medium-coarse grained litharenite by strong compaction,densification of fine grained(feldspathic)litharenite by strong compaction and medium to strong siliceous cementation. The two types of medium-coarse grained sandstones are densification after hydrocarbon charge,which experience injection of organic acid and make dissolved pore to be the major storage space. Fine grained(feldspathic)litharenite is densification before hydrocarbon charge,which experiences weak dissolution. Differences of densification modes result in variable pore structure characteristics and reservoir physical properties.
2023 Vol. 25 (3): 684-700 [
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701
ZHU Dancheng, YU Yamin, LI Ting, ZHANG Lei, LI Rangbin, YANG Minglei, ZOU Huayao
Karst development and distribution pattern of the Maokou Formation in Yuanba area,northern Sichuan Basin
The upper part of the Maokou limestones in the Yuanba area of the Sichuan Basin suffered from karstic modification during the regional regression stage at the end of the middle Permian. However,the development characteristics and distribution pattern of the karst zone are ambiguous. This paper combined core observations,well-logging lithology interpretation,horizon calibration of three-dimensional seismic data volume and seismic facies interpretation. Relative acoustic impedance inversion and seismic slice image analysis techniques can increase the interpretation resolution of the seismic data. All these data were used to establish the sequence framework,and the sedimentary facies and karst distribution were illustrated to predict the distribution pattern and mode of karst zones. The results show that(1)three third transgression-regression(T-R)sequences were developed in the Maokou Formation of the Yuanba area. The bioclastic shoals were developed in the regression cycles of the second and the third tertiary sequences. In the second sequence,the inner-platform shoals were located at the topograghic high position. Meanwhile,in the third sequence,the platform edge debris beach was developed along the margin of the platform around well YB7. (2)The development and distribution of karst zones were dominated by bioclastic shoals,which presented vertically as a surface karst zone,vertical seepage zone,high-angle dissolution fracture and cave of the deep slow flow zone,and layer-parallel caves in the phreatic zone at the core scale. (3)The karst zones are located along the coastline side of the bioclastic shoals on the plane,presenting the coastal karst development mode. (4)The layer-parallel caves at the top of the phreatic zone were the major reservoir space of the karst zone in the Maokou Formation. However,the caves were mostly occupied by sediments(mainly tuffs and limestone silts)and cements(mainly calcites)in the meteoric diagenetic realm,remaining relatively limited reserve capacity at present. The karst distribution pattern of the Maokou Formation in the Yuanba area was proposed,and its impacts on hydrocarbon exploration and risks were also discussed.
2023 Vol. 25 (3): 701-714 [
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HUMAN HISTORY PALAEOGEOGRAPHY
715
YANG Qi, XIANG Fang, RAN Honglin, GUO Yuming, LIU Jiancheng, XIE Zhenbin
Research on trench deposition characteristics of Sanxingdui platform in Guanghan,Sichuan Province
In 2020,the Sichuan Provincial Institute of Cultural Relics and Archaeology carried out archaeological exploration in the surrounding area of the burial pits. On the southern side of the Sanxingdui platform,there are trenches built on the second terrace. Paleocurrent flows from the northwest to the southeast to connect the Mamu River meandering section. The main age of trench sediments is speculated to be the third and fourth stages of the Sanxingdui culture. Through thin-section identification,scanning electron microscopy observation,and particle size analysis of the trench profile samples,it was found that the main part of the trench was composed of near-source fluvial sediments,and only pottery pieces and other relics were enriched in individual strata. The trench was dominated by natural deposition,and no large-scale anthropogenic dumping activities were found. There is no significant difference in the composition of rock debris and other components in the raw soil and trench sediments of different stages,indicating that the Jianjiang River originating in the Longmenshan tectonic belt and its tributary Mamu River have not undergone significant diversion since the late Pleistocene. The trenches experienced at least three ‘trenching-filling' processes. In the first stage,the sediments are mainly clay and silt,with weak hydrodynamic force,a stable sedimentary environment,and frequent activities of the ancients. The sediments in the second stage are mainly medium to coarse-grained sand with strong hydrodynamic force and there may be frequent floods at this time. It can be seen that the ditch banks are cut and a large area of sandy sediment is distributed across the banks. In the third stage,the hydrodynamic fluctuation of sediments was obvious and gradually stabilized in the later stage. The ancients returned to the trench area. There are traces of multi-stage man-made construction in the form of trenches,reflecting the ancients' ability to cope with climate change and natural effects.
2023 Vol. 25 (3): 715-728 [
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