海洋生物礁类型、生态功能及其生态修复

海洋生物礁是由具有造礁能力的海洋生物聚集而成的一种三维礁体结构,其形成改变了海底地貌、增加了不同尺度上的地形复杂性,为其他海洋生物提供了栖息地并维持了生物多样性。近年来,由于自然因素和人为因素影响,海洋生物礁受到了严重威胁,已成为海洋生态保护和修复领域的重要研究对象。综述了海洋生物礁的类型、生态功能及其生态修复的研究进展。根据形成海洋生物礁的优势造礁生物种类,将海洋生物礁分为海藻礁、海绵礁、刺胞动物礁、贝类礁和多毛类礁,其优势造礁生物分别是珊瑚藻和仙掌藻、钙质海绵和硅质海绵、造礁珊瑚、牡蛎、龙介虫。目前国内对海洋生物礁的全面了解相对较少,主要集中在珊瑚礁和牡蛎礁。海洋生物礁的生态功能主要有海岸防护、提供栖息地、净化水体、固碳作用和能量耦合等。全球变暖和海洋酸化等全球气候变化以及海洋污染、破坏性渔业捕捞、海岸工程、水产养殖和敌害生物等自然和人为因素对海洋生物礁构成了严重威胁。海洋生物礁的生态修复方法分为两类：在退化生物礁区投放造礁生物逐渐成礁,投放人工礁体补充造礁生物逐渐成礁。针对海洋生物礁保护和修复的需要,提出下一步应加强海洋造礁生物生态特征、海洋造礁生物种群丧失因素和海洋生物礁保护与...     

贵州罗甸干田坳晚二叠世生物礁基本特征研究*

通过综合岩相和生物群落特征对贵州罗甸干田坳晚二叠世生物礁进行分析,将研究区划分出三期造礁旋回。对造礁海绵在三个造礁阶段,以及礁前砾屑岩的成分面积进行统计,计算出各阶段的造礁成分组成状况,还原当时的造礁群落。共鉴定出纤维海绵纲3科4属,房室海绵纲9科10属和硬海绵纲2科2属。数据表明自始至终纤维海绵纲的小领针海绵属都为造礁群落里的优势生物,其中S1阶段房室海绵纲的多囊腔海绵属种、叠瓦腔海绵属种和泡腔海绵属种为造礁主体;S2阶段小领针海绵和一纤维海绵未知属种为造礁主体,S3阶段房室海绵的多囊腔海绵占造礁主导地位。统计表明造礁海绵群团的分异度由S1至S3期降低明显。同时着重对本礁点主体的S2阶段骨架礁岩各个部分的结构特征进行细致分析,尤其是RFC的形成历史进行探讨,碳氧同位素测试得到的数据表明S2阶段古水温经历了高达16℃左右的波动,而RFC形成时的古水温为37.86℃,它是一种高温海水的反映;最后通过与南盘江盆地同期的紫云礁和茅口期的广西隆林礁进行对比,揭示它们的成礁模式和演化的异同。     

钙质海锦之古生态

古生代生物礁中钙质海绵（纤维海绵、房室海绵、硬海绵）的生态位在中三叠世以后被生态竞争能力更强的六射珊瑚所占据。在古生代和中三叠世的钙质海绵礁上,０－１０ｍ深度内钙质海绵很发育。由于与钙藻共生,典型的造礁钙质海绵生活在透光带以内,并且在其上部更丰富。钙质海绵礁也会生长到破浪带内并受风浪的破坏而形成倒骨岩和骨屑岩。对古生代的钙质海绵礁而言,倒骨岩和骨屑岩形成于０－３ｍ水深范围内,亮晶骨架岩形成于３－１     

钙质海绵之古生态

古生代生物礁中钙质海绵(纤维海绵、房室海绵、硬海绵)的生态位在中三叠世以后被生态竞争能力更强的六射珊瑚所占据.在古生代和中三叠世的钙质海绵礁上,0-10m深度内钙质海绵很发育.由于与钙藻共生,典型的造礁钙质海绵生活在透光带以内,并且在其上部更丰富.钙质海绵礁也会生长到破浪带内并受风浪的破坏而形成倒骨岩和骨屑岩.对古生代的钙质海绵礁而言,倒骨岩和骨屑岩形成于0-3m水深范围内,亮晶骨架岩形成于3-10m深度范围内,灰泥骨架岩形成于10-20m的水深,障积岩形成于20-30m的水深,潜障积岩形成于30-40m的水深.钙质海绵的生长形态与水深的关系与六射珊瑚与水深的关系一样:细枝状的钙质海绵生长在最浅的水中(相当于礁生长带的上部),在稍深的水中(相当于礁生长带的中部和下部)各种形态的海绵都会出现,在更深的水中可以出现特别大的、锥状的海绵.     

海绵的分类、演化及其地质意义

本文简述了海绵动物的基本特征,比较了硅质海绵与钙质海绵在骨针及骨骼结构上的不同,认为骨针性质与硬体骨骼结构是海绵分类的主要依据。据此把海绵动物划分为普通海绵纲(Class Demospongea)、六射海绵纲(Class Hexactinellida)、钙质海绵纲(Class Calcispongiae)、异射海绵纲(Class Heteractinida)和硬骨海绵纲(Class Sclerospongiae),并进一步讨论了不同类别海绵在地史时期的分布及演化。提出海绵除可作为判别环境的标志外,还是重要的造礁生物。地史时期由海绵形成的成礁期有3次,它们与不同类型碳酸盐岩隆的生成及油气的聚集有密切关系。     

川西北上三叠统卡尼阶马鞍塘组中部硅质海绵礁

川西北地区绵竹汉旺青岩沟、观音崖以及安县雎水剖面三叠纪卡尼期马鞍塘组硅质海绵礁群生长于碳酸盐岩缓坡带,可划分为礁基、礁核、礁翼、礁间沉积等亚相,据内碎屑含量、化石埋葬学特征以及灰泥等基质比例厘定岩相和群落特征。礁灰岩主要为海绵格架岩和钙质微生物凝块岩,附礁生物类型包括有孔虫类、双壳类、棘皮类、介形类、腕足类、粗枝藻类、钙质海绵等。马鞍塘组海绵礁终结之后上覆黑色页岩沉积。晚三叠世卡尼期气候骤变在全球生物圈引发广泛的效应,海平面升降速率相对海绵礁的生长速率较大,加之构造活动频繁,大火山岩省集中爆发以及超级季风盛行,从而导致了硅质海绵礁灭绝。     

湖北利川二叠纪生物礁的埋藏学特征及其环境意义*

二叠纪钙质海绵礁的研究已逾百年,但缺乏埋藏学方面的研究。本文选取鄂西利川典型钙质海绵礁剖面,对造架生物的属种组成、保存状态(直立还是倒伏)、个体大小、古石孔藻包壳和泥晶含量进行统计研究。共鉴定出17个属种的钙质海绵和一个属种的水螅;通过统计研究发现,含钙质海绵的灰岩厚98m,其下部4/5厚度所含钙质海绵以倒伏的为主,上部1/5厚度以直立的为主;含倒伏钙质海绵的灰岩中藻包壳(古石孔藻)不发育,钙质海绵以直立为主的灰岩中,藻包壳发育;钙质海绵的个体大小由海绵灰岩下部而上增大不明显;泥晶基质的含量自海绵灰岩的下部而上明显减少。由此推断:下部的钙质海绵灰岩形成时由于没有藻包壳,大多被风浪打倒。上部具有藻包壳的钙质海绵灰岩,尽管形成时的水动力能量更强,但由于有藻包壳,其抗风浪能力得到加强,所以大多直立保存。     

中国南方二叠纪礁类型及成礁的控制因素

我国南方的二叠纪礁主要分布在黔、桂、川东、湘鄂西以及中下扬子地区，有两次大的成礁期，即茅口期和长兴期，且以长兴期礁发育好、分布普遍。根据礁的成因、组构及礁岩类型，将南方二叠纪礁分成４类：生物礁，生物丘，灰泥丘和地层礁。各类礁均具有其自身独有的特征，同时它们的形成、演化和消亡，明显地受到古构造（尤其是古断裂）、古地理、古环境和海水进退、海平面升降的严格控制。     

广西西部二叠纪生物礁中的海绵、水螅动物化石

广西西部田林,凌云、凤山地区二叠纪生物礁的造礁生物－海绵、水螅化石保存完美。文中描述串管海绵7属：Stylothalamia,Lichuanospongia,Tebagathalamia,Imbricatocoelia,Intrasporeocoelia,Rhabdactinia,Lingyunocoelis;纤维海绵3属：Peronidella,Intratubospongia,Cavusonella;水螅1属Radiotrabeculopora以及海托盘类Calathium,其中Lingyunocoelia spherica为新属新种,Lichuanospongia guangxiensis为新种,其它均为中国南方二叠纪生物礁内常见分子。Senowbari-Daryan(1990)提出以Discosiphonella来代替Cystauletes,Ascosymplegma,Lichunospongia3属,但Lichuanospongia的房室形状和中央腔缺失横板（泡沫板）显著不同于Discosiphonella,因此文中仍把Lichuanospongia视作独立属,Lingyuncoelia gen.nov。与Sollasia,Girtyocoelia相似,但房室外壁缺乏任何种类的穿孔,因此明显不同于后两属,作者仍把Radiotrabeculopora视为螅纲内的一属,而没有归于纤维海绵目,因为它最明显的特征是发育分布较规则的放射状支柱（不能视为骨纤构造）,且那些纵向分布的出水管实际上应视为支柱之间的沟道。     

早-中奥陶世瓶筐石礁丘:历史和古生态学

瓶筐石(Calathium)是早-中奥陶世期间常见的重要的造礁生物之一,与菌藻类、海绵以不等丰度相聚集共同组成位于浅海区的礁丘群落.早期阶段(特马道克期-弗洛期早期)以瓶筐石-海绵-菌藻类礁群落为主,其后因海绵丰度减弱而逐渐演替为瓶筐石-菌藻群落,达瑞威尔期以瓶筐石为群落主体的礁丘分布已趋于局限,中奥陶世晚期伴随着珊瑚...     

四川华蓥山地区晚二叠世生物礁中“板状水螅”化石的初步研究

所讨论的“板状水螅”是一类分类位置尚有争议的化石，为华蓥山地区上二叠统生物礁的主要造礁生物之一。这里描述了３属３种．其中包括２新属和３新种．它们是Ｐｓｅｕｄｏｐａｌａｅｏａｐｌｙｓｉｎａｈｕａｙｉｎｇｅｎｓｉｓ，Ｐｈｒａｇｍｏｒｐｈａａｓｉａｔｉｃａ和Ｃｎｉｄｏｐｏｒａｔｕｂｅｒｃｕｌｏｓａ。     

Upper Permian coral reef and colonial rugose corals in northwest Hunan, South China

Summary The roles of Permian colonial corals in forming organic reefs have not been adequately assessed, although they are common fossils in the Permian strata. It is now known that colonial corals were important contributors to reef framework during the middle and late Permian such as those in South China, northeast Japan, Oman and Thailand. A coral reef occurs in Kanjia-ping, Cili County, Hunan, South China. It is formed by erect and unscathed colonies ofWaagenophyllum growing on top of one anotherin situ to form a baffle and framework. Paleontological data of the Cili coral reef indicates a middle to late Changhsing age (Late Permian), corresponding to thePalaeofusulina zone. The coral reef exposure extends along the inner platform margin striking in E-S direction for nearly 4 km laterally and generally 35 to 57 m thick. The Cili coral reef exhibits a lateral differentiation into three main reef facies; reef core facies, fore-reef facies, and marginal slope facies. The major reef-core facies is well exposed in Shenxian-wan and Guanyin-an sections where it rests on the marginal slope facies. Colonial corals are dispersed and preserved in non-living position easward. Sponges become major stabilizing organisms in the eastern part of Changhsing limestone outcrop in Kanjia-ping, but no read sponge reefs were formed. Coral reefs at Cili County in Human are different distinctly from calcisponge reefs in South China in their palaeogeography, lithofacies development, organic constitutuents, palaeoecology and diagenesis. The Cili coral reef also shows differences in age, depositional facies association, reef organisms and diagenesis from coral reefs in South Kitakami of Japan, Khorat Plateau of Thailand, and Saih Hatat of Oman. Although some sponge reefs and mounds can reach up to the unconformable Permian/Triassic boundary, coral reef at Kanjia-ping, Cili County, is the latest Permian reef known. This reef appears to had been formed in a palaeoenvironment that is different from that of the sponge reefs and provides an example of new and unique Permian reef type in South China, and could help us to: 1) understand the significance of colonial corals in Permian carbonate buildups; 2) evaluate the importance of coral community evolution prior to the collapse of reef ecosystems at the Permian/Triassic boundary; 3) better understand the effects of the biotic extinction events in Palaeotethys realm; 4) look for environmental factors that may have controlled reefs through time and space, and 5) provide valuable data for the study of Permian palaeoclimate and global evolutionary changes of Permian reefs and reef community.     

Microfacies of a Permian calcisponge reef in Lichuan,western Hubei,South China

The Lichuan Jiantianba reef is located at the platform margin between the carbonate platform and the marine trough in western Hubei, China. The water depth of this area became shallow in the late Permian Changhsingian Age, and a huge aggradation-progradation platform marginal reef developed. Based on precise field measurements and microscopic observation, this paper describes the petrological characteristics and biological assemblages of the reef in detail and distinguishes 10 microfacies: small echinoderm wackestone, sponge floatstone, bound sponge bioliestone, bound sponge framestone, large echinoderm wackestone, red algal limestone, bioclastic grainstone, dasycladales wackestone, shelly wackestone, and microbialites. Sponge floatstone and bound sponge bioliestone are defined as toppled sponge limestone. Comparisons of the petrological characteristics and biotic association of toppled sponge limestone, bound sponge framestone and bioclastic wackestone and grainstone revealed that the toppled sponge limestone and the bound sponge framestone are similar in sponge content in terms of the types and contents of reef-dwellers, except that the sponge content is slightly lower, and the preservation state is mainly toppled for the former and upright or inclined for the latter. The toppled sponge limestone is dominated by tabular calcite, and the bound sponge framestone is dominated by fibrous calcite. The bioclastic wackestone and grainstone do not contain reef-building sponge organisms, and the bioclast content is very high and often dominated by a certain class, such as echinoderms, foraminifers, green algae or shells. The toppled sponge limestone below the framework, which was classified as fore-reef breccia or bioherm bafflestone-bindstone in previous studies, should be defined as reef-core sponge limestone deposited in situ that experienced serious post-karstification. The vertical evolution of the sedimentary facies of the reef is analyzed based on the microfacies and sedimentary environment. The toppled sponge limestone and the bound sponge framestone should be classified as reef core, which is the only subfacies of the reef facies. The underlying small echinoderm wackestone should be classified as the shelf facies, whereas the overlying bioclastic wackestone and grainstone should be classified as the open platform facies. These classifications represent a modification of the sedimentary facies subdivision of the Jiantianba reef in Lichuan, Hubei Province, South China, and provide a new reference model for the subdivision of the Permian calcisponge reefs on platform margin.     

Cambrian Series 3 lithistid sponge–microbial reefs in Shandong Province,North China: reef development after the disappearance of archaeocyaths

The Cambrian Series 3 Zhangxia Formation in Shandong Province, North China, includes small‐scale lithistid sponge–microbial reefs. The lithistid sponges grew on oolitic and bioclastic sediments, which were stabilized by microbial activities. The relative abundances of microbial components (e.g. calcimicrobe Epiphyton and stromatolites) vary among the reefs. However, the microbial components commonly encrusted or bound the lithistid sponges, formed remarkable encrustations on the surfaces of the sponges. Epiphyton especially grew upward and downward. The lithistid sponges thus provided substrates for the attachment and development of microbes, and the microbes played essential roles as consolidators, by encrusting reef‐building sponges. Additionally, the lithistid sponges were prone to degradation via microbial activities and diagenetic processes, and were thus preserved as micritic bodies, showing faint spicular networks or abundant spicules. Such low preservation potential within the reef environment obscured the presence of the sponges and their widespread contribution as reef‐building organisms during the Cambrian. During the prolonged interval after the demise of archaeocyaths, purely microbial reefs, such as stromatolites and thrombolites have been considered to be the principal reef builders, in association with rare lithistid sponge–microbial associations. However, recent findings, including those from Shandong Province and Korea, suggest that the lithistid sponge‐bearing reefs were more extensive during the Epoch 3 to the Furongian than previously thought. These lithistid sponge–microbial reefs were precursors of the sponge–microbial reefs that dominated worldwide in the Early Ordovician.     

广西、贵州和川东二叠纪生物礁的钙藻化石及其古生态环境

广西,贵州和川东二叠纪礁相岩石和礁后相岩层内获得了红藻Solenoporella,Gymnocodium,Permocalcu-lus;绿藻Anthracoporella,Mizzia以及显微疑难藻类化石Pseudovermiporella,Tubiphytes等,除了广西隆林有中二叠世茅口期藻类化石外,其它均属于晚二叠世乐平世的分子,这些藻类植物一般生活于热带和亚热带,正常盐度的浅海水内,其水深不大于30m,川东,鄂西晚二叠世礁属于浅水海绵礁,而非深水礁。     

Anisian (middle triassic) buildups of the Northern Dolomites (Italy): The recovery of reef communities after the permian/triassic crisis

Summary After the end-Permian crisis and a global ‘reef gap’ in the early Triassic, reefs appeared again during the early Middle Triassic. Records of Anisian reefs are rare in the Tethys as well as in non-Tethyan regions. Most Anisian reefs are known from the western part of the Tethys but there are only very few studies focused on biota, facies types and the paleogeographical situation of these reefs. From the eastern part of the Tethys, Anisian reefs, reefal buildups or potential reef-building organisms have been reported from different regions of southern China. Most of the Anisian reefs known from western and central Europe as well as from southern China seem to be of middle and late Pelsonian age. The study area is situated in the northern Dolomites (South Tyrol, Italy) southeast of Bruneck (Brunico). It comprises the area between Olang (Valdaora) and Prags (Braies). The study is based on detailed investigations of the regional geology, stratigraphy and lithofacies (R. Zühlke, T. Bechst?dt) as well as on a comprehensive inventory of Anisian reef organisms (B. Senowbari-Daryan, E. Flügel). These data are used in the discussion of the controls on the recovery of reefs during the early Middle Triassic. Most late Anisian reef carbonates studied are represented by allochthonous talus reef blocks of cubicmeter size. Small biostromal autochthonous mounds are extremely rare (Piz da Peres). The reef mounds as well as most of the reef blocks occur within the middle to late Pelsonian Recoaro Formation. They were formed on the middle reaches of carbonate ramps in subtidal depths, slightly above the storm wave base with only moderate water energy. Most lithotypes observed in the reef blocks correspond to sponge and/or algal bafflestones. Low-growing sessile organisms (Olangocoelia (sponge, alga?), sphinctozoan sponges, bryozoans, soleno-poracean algae, corals) and encrusting epibionts (sponges, porostromate algae, cyanophycean crusts, foraminifera, worms, microproblematica) created low cm-sized biogenic structures (bioconstructions) which baffled and bound sediment. Organic framework was only of minor importance; it is restricted to theOlangocoelia lithotype. Framework porosity was small in these reef mounds. Submarine carbonate cements, therefore, are only of minor importance s compared with Permian or Ladinian reefs. The relatively high number of lithotypes encountered in the reef blocks indicates a high biofacies diversity. Regarding the relative frequency, the diverse biota consist in descending order ofOlangocoelia, sponges (sphinctozoans, inozoans, siliceous sponges), bryozoans, porostromate algae and worm tubes. The sphinctozoans are characterized by small, mostly incrusting forms. The numerical diversity (species richness) is low compared with late Permian or Ladinian and late Triassic sphinctozoan faunas occurring within reefs. Following the sponges, monospecific bryozoans (Reptonoditrypa cautica Sch?fer & Fois) are the most common organisms in the reef limestones. Porostromate algae were restricted to areas within the bioconstructions not inhabited by sponges. The low-diverse corals had no importance in the construction of an organic framework. Surprisingly, microbial crusts are rare or even lacking in the investigated Anisian bioconstructions. This is in contrast to late Permian and Ladinian as well as Carnian reefs which are characterized by the abundance of specific organic crusts. The same comes true for‘Tubiphytes’ which is a common constituent in Permian, Ladinian and Carnian reef carbonates but is very rare in the Anisian of the Olang Dolomites. Instead of‘Tubiphytes’ different kinds of worm tubes (spirorbid tubes, Mg-calcitic tubes and agglutinated tubes) were of importance as epifaunal elements. Macrobial encrustations consisting of characteristic successions of sponges, bryozoans, algae, worm tubes and microproblematica seem to be of greater quantitative importance than in Ladinian reefs. Destruction of organic skeletons (predominantly of bryozoans) by macroborers (cirripedia?) is a common feature. The Anisian reef organisms are distinctly different from late Permian and from most Ladinian reef-builders. No Permian Lazarus taxa have been found. New taxa: Sphinctozoan sponges—Celyphia? minima n.sp.,Thaumastocoelia dolomitica n. sp.,Deningeria tenuireticulata n. sp.,Deningeria crassireticulata n. sp.,Anisothalamia minima n.g. n.sp., Inozoan sponges-Meandrostia triassica n.sp. Microproblematica-Anisocellula fecunda n.g. n.sp., Porostromate alga-Brandneria dolomitica n.g. n.sp. Most of our data are in agreement with the model described byFois & Gaetani (1984) for the recovery of reef-building communities during the Ansian but the biotic diversity seems to be considerably higher than previously assumed. Anisian deposition and the formation of the reef mounds within the Pelsonian Recoaro Formation of the Dolomites were controlled by the combined effects of synsedimentary tectonics and eustatic changes in sea-level. During several time intervals, especially the early Anisian (northern and western Dolomites: tectonic uplift), the early Pelsonian (eastern Dolomites: drowning) and the late Illyrian (wide parts of the Dolomites: uplift and drowning), the sedimentation was predominantly controlled by regionally different tectonic subsidence rates. The amount of terrigenous clastic input associated with synsedimentary tectonics (tectonic uplift of hinterlands) had a major influence on carbonate deposition and reef development. The re-appearance of reef environments in the Olang Dolomites was controlled by a combination of regional and global factors (paleogeographic situation: development of carbonate ramps; decreasing subsidence of horst blocks; reduced terrigenous input; moderate rise in sea-level).     

Distribution and evolution of Carboniferous reefs in South China

Reefs are sensitive proxies for palaeontological, palaeoenvironmental, and palaeogeographical changes during geological history. In South China, after the collapse of the reef ecosystem during the Frasnian-Famennian and Hangenberg mass extinction events, Carboniferous reefs underwent evolutionary episodes of recovery, decline, and turnover, which were controlled by changes of reef-builders abundance, sedimentary facies, relative sea level, and even global climate. In Tournaisian times, only a few Waulsortian-like banks have been found in Liuzhou, Guangxi without metazoan reefs, which were caused by the lack of reef-builders, such as colonial rugose corals and bryozoans, and the dominant non-carbonate facies (shale, mud stone and sandstone) driven by low relative sea level. The absence of mud mounds in the early Viséan was attributed to the regression event during the Tournaisian-Viséan boundary. During Viséan times, bryozoan-coral reefs in Huishui, Guizhou and Tianlin, Guangxi occurred during a time of increasing biodiversity and carbonate facies resulting from relative sea-level rise. The number of potential reef-builders as colonial rugose coral and bryozoan genera significantly increased in Viséan times in South China. The reef abundance declined during Serpukhovian times in South China and the controlling factors were decreasing abundance of potential reef-builders and developing non-carbonate facies due to a relative sea-level fall. The sedimentary facies were characterized by shale, mud stone, sandstone, and dolostone during this time. A distinct change in reef types occurred after the Mississippian-Pennsylvanian boundary, when phylloid algae and red algae reefs (distributed in Ziyun, Guizhou and Beibuwan, Guangxi) replaced metazoan reefs and became the dominant role in reef ecosystem. This reef turnover event may be triggered by the dramatic relative sea-level fall during the mid-Carboniferous, and continued low relative sea level in South China and global flourish of phylloid and red algae during Pennsylvanian times. Grainstone and dolomitic limestone were the main composition of the platform sedimentary facies in South China during Pennsylvanian times. In addition, global climate cooling and warming, resulted from the waxing and waning of Gondwana glaciation, may also influence the reef evolution in South China, as evidenced from the consistent transgression and regression events and reef evolutionary pattern between South China and globe during the Carboniferous.