The new genus and species, Jurassephemera zhangi gen. et sp. nov., belonging to the extinct family Sharephemeridae (Ephemeroptera: Mesephemeroidea), is established from the late Early Jurassic interval of the Shiti Formation of Guangxi Zhuang Autonomous Region, South China. The new genus and species is characterised by its moderate size; small head with reduced compound eyes; body with ten abdominal segments; round-triangular forewing shape; vein R dividing three times, forming five veinlets and three triads; veins MA, MP, and CuA straight, all basally forking once with single triads between; crossveins well developed; and hind wing oval, much smaller than forewing, with veins generally radial and single. SEM observations also reveal that crossveins are much more developed than previously recognised under optical illumination. The forewing venation of all sharephemerid genera is compared. The first report of this family in China herein increases the diversity and palaeogeographic distribution of Sharephemeridae.

Resource pulses, occasional events of ephemeral resource superabundance, represent a fundamental mechanism by which energy, nutrients, and biomass are transported across ecotones. They are widespread in extant ecosystems; however, little is known about their deep-time record. We report the earliest-known mayfly swarm from the Early Jurassic Xiwan biota of southern China. Our taphonomic and sedimentological analyses show that these mayflies were buried on the bottom of a calm lake after post-mating death. Our suite of analyses suggests that the complex mating-swarm behavior was already well established in mayflies by the Early Jurassic. More importantly, our find represents the earliest-known resource pulse of insects, a mechanism that can play a substantial role in nutrient transport from aquatic ecosystems to surrounding terrestrial ecosystems. Such an aquatic-terrestrial ecosystem linkage may be a key novelty in Mesozoic lacustrine ecosystems. Our results highlight the underappreciated ecological significance of insects in deep-time terrestrial ecology.

晚古生代右江盆地分布有众多规模不等的孤立碳酸盐岩台地,对台地形成与演化的研究对于认识右江盆地的构造演化、 全球海平面变化等具有重要的意义.通过对隆或台地研究认为,盆地-台地间可划分为孤立台地相及斜坡-盆地相两大相区,并可以进一步细分为局限台地、开阔台地、 台地边缘浅滩、 台地边缘礁、台沟、台地前缘斜坡及深水盆地相7种沉积相类型.台地孕育于早泥盆世晚期,并逐步演化发展,至早三叠世最终消亡,可划分为孤立碳酸盐岩台地孕育阶段(D1—D2)、 孤立碳酸盐岩台地成型阶段(D3)、孤立碳酸盐岩台地持续演化阶段(C1—P2)和孤立碳酸盐岩台地淹没收缩阶段(P3—T1)等4个阶段.隆或台地是右江盆地在晚古生代发生了强烈的扩张、沉降,扬子台地边缘破裂形成规模不等的块体逐步向盆地内滑移并接受沉积形成的,其后逐步发展演化直到最终淹没消亡,该过程与右江盆地的构造演化密切相关,同时受全球海平面变化和盆地内陆源物质的输入影响.

本文系统研究了贵州独山马道剖面泥盆-石炭纪之交的牙形刺,共鉴定出6属25种(包括亚种、比较种、未定亚种).根据牙形刺的产出情况,在该剖面自下而上可以识别出3个牙形刺带,即法门阶的Bispathodus ultimus带,杜内阶的Siphonodella isosticha带和Polygnathus communis carina带.基于详细的牙形刺材料,讨论了上述生物带的时限和范围,并与其他地区进行了对比.虽然尚未在本剖面找到泥盆-石炭系界线的标志分子Sipho-nodella sulcata,但综合考虑其他牙形刺的分布以及岩性变化特征,可以将泥盆-石炭系界线暂置于融县组上部白云岩段的底部.以上成果将加深对于这一层段的牙形刺面貌以及牙形刺生物带的理解,也将为开展华南泥盆-石炭系界线再研究以及泥盆-石炭纪之交的生物-环境事件研究提供借鉴.

文章通过分析广西巴马地区的地质背景及在1:5万巴马地区区域地质调查工作中发现的透闪玉石矿的宝石学特征、岩相学特征,认为广西巴马地区与贵州罗甸、广西大化已发现的透闪石玉矿床空间毗邻,地质背景相似,具有较好的透闪石玉成矿条件,找矿潜力大.

Carbonaceous rock is a special soft rock containing TOC organic carbon 6%∼40%. In order to reveal the influence of engineering characteristics of carbonaceous rock on the engineering construction, firstly the stratigraphic distribution of carbonaceous Rocks in Guangxi is investigated, and the genetic mechanism and tectonic environment of carbonaceous rocks are discussed. Secondly, the influence of pore microstructure on the disintegration characteristics of carbonaceous rocks is analyzed. The role of geochemical characteristics of carbonaceous rocks (mineral composition, TOC total organic matter content, and type) on engineering properties is revealed. Finally, combined with the distribution, structure, microstructure, and microscopic characteristics of the previous studies, the disintegration mechanism of carbonaceous rocks in water swelling and heat dehydration is discussed. The results are as follows. (1) Carbonaceous rocks in Guangxi are mainly distributed in Devonian, Carboniferous, and Cambrian systems. It is mainly formed in anoxic and reductive deep water basins, slopes, and relatively confined coastal lagoons and swamps. The carbonaceous rocks in the Devonian Luofu formation are most typical. (2) The pores of carbonaceous rocks are divided into mineral pores, organic matter pores, and microfracture, which are mainly mineral pores. The more developed pores in mineral pores are intragranular dissolved pores. Secondly, mineral intergranular pores and a small amount of intergranular dissolution pores and less inner pores. Organic matter porosity increases with the increase of shale organic carbon content and maturity, but the shale porosity and adsorption capacity decrease when shale maturity reaches more than 2.4%. (3) Clay minerals in carbonaceous shale mainly consist of illite and illite/montmorillonite layer, which have water swelling and heat dehydration. The total average value of TOC (total organic matter content) is more than 1%, which belongs to carbonaceous rocks of medium high grade hydrocarbon source rocks. Organic matter is mainly dominated by type I and II1-II2 type with large hydrocarbon generating potential, which is prone to oxidation-reduction reaction and cause rock disintegration.

Abundant Triassic radiolarian fossils were obtained from varicolored bedded cherts exposed in the Buruocang section near Jinlu village, Zedong, southern Tibet. The radiolarian‐bearing rocks represent fragmented remnants of the Neotethys oceanic sediments belonging to the mélange complex of the east part of the Yarlung‐Tsangpo Suture Zone. Two new middle Late Anisian radiolarian assemblages recognized from this section named Oertlispongus inaequispinosus and Triassocampe deweveri, respectively, are compared with those known from Europe, Far East Russia, Japan, and Turkey. These Anisian radiolarian fossils are the first reported in southern Tibet and the oldest radiolarian record within the Yarlung‐Tsangpo Suture Zone. They improve time constraints for the evolution of Neotethys in southern Tibet.

作为错时相沉积之一的巨鲕灰岩在我国华南早三叠世地层中广泛出现,在寒武纪之后本已消失的这种沉积类型为什么会在早三叠世又重新出现？在四川江油渔洞子下三叠统飞仙关组鲕粒灰岩的底部,产有一套巨鲕灰岩,通过高倍显微镜及扫描电镜的深入研究,首次发现在巨鲕灰岩的鲕粒和围岩中充满丰富的疑似底栖蓝细菌、疑似颗粒状浮游蓝细菌及其他超微化石.根据这些疑似底栖蓝细菌的结构和构造特点,可以划分出下列几种类型:疑似蛛网状蓝细菌,疑似微球状蓝细菌,疑似网格状蓝细菌,疑似蠕虫状蓝细菌,疑似直管状蓝细菌,疑似链状蓝细菌,疑似花瓣状蓝细菌和Renalsis,疑似颗粒状浮游蓝细菌(主要有两种类型:简单的椭球粒和螺旋状球粒).超微化石包括钙球和铃铛形超微化石.疑似底栖和浮游蓝细菌及其他超微生物的大量繁盛,是二叠纪-三叠纪之交海洋生态环境恶化、海洋底栖动物大灭绝所产生的后果.这一发现不仅使我们在微观世界和超微世界里重新认识巨鲕灰岩的成因,它是生物和沉积两种主要因素共同作用的结果,从而对巨鲕灰岩的时代分布做出了很好的解释;同时,也可以帮助我们重塑当时该地区的海洋古生态系统.

Numerous moderately preserved radiolarians of Tethyan affinity were extracted from a purple-red chert sample from the Luoqu Section on the southern side of the Yarlung-Tsangpo suture zone in the Xigaze area, southern Tibet. Ninety-three species belonging to 35 genera are recognized, of which one is described as Citriduma pentaptera sp. nov.; most of them are reported from Tibet for the first time. Significantly, this radiolarian assemblage of nassellarians, subordinate spumellarians and rare entactinarians can be compared with those in Oman, Japan, Oregon and Queen Charlotte Islands and is further assigned to the Eucyrtidiellum nagaiae-Praeparvicingula tlellensis zone of late Pliensbachian in age. This indicates that the pelagic deposits of the Neo-Tethys Ocean in the Xialu area were laid down at least during or since the late Pliensbachian, much earlier than the Aalenian age previously considered.

The disaster event of marine ecological environments at the end-Permian resulted in mass extinction of marine benthic fauna and the explosion of Early Triassic cyanobacteria mainly found from microbialite.The abundant doubtful cyanobacteria are first discovered in the giant oolitic limestone of the lower part of the Feixianguan Formation.Their types and structures are very different from cyanobacteria found in the microbialite at the bottom of the Feixianguan Formation reported before.The gathering of doubtful cyanobacteria in the giant ooids and host rocks implies that the formation of the giant oolitic limestone was closely related to the doubtful cyanobacterial activities.In this case it is similar to the formation of microbialite found at the bottom of the Feixianguan Formation.It can be inferred that two episodes of Early Triassic doubtful cyanobacterial explosions occurred in this region and provide a clue that there were two events of marine ecological environmental deteriorations at least.However,the Early Triassic explosions of cyanobacteria are of benefit to the improvement of marine ecological environments and biotic recovery.Therefore,it is significant for the very late Early Triassic and the Middle Triassic overall biotic recovery and radiation.

The abundant nannofossils including "doubtful" nannobacteria and "doubtful" coccoid plankton cyanobacteria are first discovered in the giant oolitic limestone of the lower Feixianguan Formation at the Yudongzi section,Jiangyou,Sichuan,SW China.The discovery indicates that the formation of the giant oolitic limestone was possibly related to the activities of "doubtful" coccoid plankton cyanobacteria and benthic cyanobacteria.This paper also suggess the mechanism of non-organic calcites formation.As the main members in the marine palaeoecological system in the Early Triassic of this region,the "doubtful" benthic cyanobacteria and plankton coccoid cyanobacteria built a simple trophic web.Their expansion was due to the deterioration of marine environments,which also caused the extinction of benthic fauna occurred in this period.

This paper deals with the calcareous nannofossils from biogenetic reef complexes in the early Miocene to Quaternary of well XK1,Xisha Island,South China Sea.A total of 831 core samples at 1.5 m sampling intervals have been analyzed from the 0.10-1267.80 m of the XK1 well.Calcareous nannofossils has a lower abundance and diversity,and they are found in only 48 samples.17 species and 1 indet,species referred to 10 genera have been identified.The main species are Calcidiscusleptoporus,C.macintyrei,Coccolithus pelagicus,Cyclicargolithus floridanus,Gephyrocapsa caribbeanica,G.oceanica,Helicosphaera carteri,H.euphratis,Pontosphaera multipora,Reticulofenestra minuta,R.minutula,Sphenolithus abies,S.mori formis,S.neoabies.Based on the calcareous nannofossil events,assemblages and distribution,combined with zones of foraminifera and calcareous algae,five stratal sections can be divided.They are discussed from the top to the bottom as follows:1) 0.10-212.20 m is assigned to Quaternary;2) 214.29-328.69 m belongs to Pleistocene—upper Pliocene;3) 330.97-598.12 m is divided into lower Pliocene — upper Miocene;4) 599.53-1231.62 m is assigned to middle Miocene—lower Miocene;5) 1233.62-1267.8 m belongs to lower Miocene.According to the calcareous nannofossils,the age of the interval 0.10-1267.80 m is early Miocene to Quaternary.The discovery of calcareous nannofossils is very important to the biostratigraphic division of well XK1.

本文描述的放射虫化石新材料发现于藏南桑单林剖面中部灰绿色硅质岩和硅质泥岩层段,共计21属33种,含5个未定种.通过与北大西洋和南太平洋古新世放射虫化石带进行对比,该放射虫动物群可归为晚古新世RP6 Bekoma campechensis带和RP7 Bekoma bidartensis带,时代为Selandian期至Thanetian晚期.综合剖面岩相、构造特征和已报道的放射虫化石组合,本文认为桑单林剖面是一套构造成因的混杂堆积,可能代表了新特提斯洋俯冲和后期印度-欧亚板块碰撞过程中形成的增生杂岩系.区域上,仲巴-萨嘎-江孜一带发现的晚古新世放射虫动物群和海相玄武岩表明,在晚古新世最晚期(大约56 Ma),西藏南部还存在着较大规模的深海沉积.

This paper reports the first discovery of Spirorbis phlyctaenain China which was found in the microbialite at the bottom of the Lower Triassic Feixianguan Formation(Greisbachian)of the Yudongzi Section of Jiangyou,Sichuan Province.It offers information about the composition,structure and paleoecology of the Early Triassic biologic community associated with the benthic microbial community.The occurrence of serpulid spirorbis belonging to annelida in the zone of conodont Hindeodus parvus further inplies that annelida is one of pioneers of Early Triassic biologic recovery.In comparison with S.phlyctaenafound in Siusi Member of the Werfen Formation from northern Italy,the S.phlyctaenaat the bottom of the Lower Triassic Feixianguan Formation is nearly same in size.The Lilliput efficiency happens in brachiopod Lingunellabut not in ser pulid spirorbis.