运用层序地层学的原理和方法， 重新探讨了蓟县中、新元古代层序及不同层序的层序界面、副层序的类型、相演化及海平面变化；初步识别出１８个层序界面，因而将其划分为１７个层序，其中有 ５个层序界面与岩组界线不一致。通过生物的丰度探讨了生油层，通过岩相组合探讨了可能的储油层。用新的观点和方法研究并解释这一中、新元古代地层剖面时注 重对已有资料的二次开发。

An important progress has been achieved in the completion of the Meso-Neoproterozoic hypostratotype section in Jixian.However,lots of key horizons have not yet been calibrated with the high-quality isotopic ages,which has a remarkable influence upon the competitiveness of GSSA in the Jixian section.A zircon U-Pb age was first obtained for the ash bed in the upper part of the Jixian section,yielding a weighted mean 207Pb/206Pb age of(1368±12) Ma(by Gao Linzhi et al.,2007;analyzed in Beijing SHRIMP Center).In addition,the new age of the Dahongyu Formation(1625.9±8.9) Ma in the Jixian section and that of the Xiamaling Formation(1370±11) Ma in Western Hills of Beijing were obtained and then examined by the SHRIMP Center in Curtin University,Perth,Western Australia.A breakthrough was made in Meso-Neoproterozoic chronostratigraphic research,and the location of the Jixian section was restored in the geological chart.At the same time,a new Meso-Neoproterozoic classification was advanced for the Jixian section.The SHRIMP zircon ages((1368±12) Ma and (1370±11) Ma) have raised new problems before us,and Chinese geologists must face the following challenges: ① The top boundary age of the Tieling Formation is limited at 1400 Ma or younger.② The time limit of the hypostratotype of the Changcheng and Jixian systems may be in 1800～1200 Ma,not in 1800～1000 Ma.According to the age of the Xiamaling Formation,the Changcheng System is limited in 1800～1600 Ma and the Jixian System is in 1600～1400 Ma,being respectively the lower and the middle part of Mesoproterozoic strata.③ The dating serves as evidence of chronostratigraphy for diabase dikes,which are well developed in Meso-and Neoproterozoic strata in the North China Old Land.The strata of 1200～800 Ma in the Yangtze Platform and on the southern margin of the North China Old Land should be further investigated and interpreted.However,the zircon dating is an important achievement of the Precambrian chronostratigraphy in China,which increases the international competitiveness of the Jixian section.

建立中国晚前寒武纪地层的标准剖而,并使其成为国际地层对比的参考标准,一直是中国地质学家的追求.华北蓟县中、新元古代地层一直作为这一标准地层的主要研究剖面,已进行了岩石地层、生物地层、化学地层、磁性地层和层序地层等多学科研究.但是,高质量的同位素年代学研究和以此为基础的年代地层框架的优化一直是华北古陆中、新元古界研究的薄弱环节.长期以来,由于关键层位和关键界而缺乏高质量的同位素年龄标定,致使蓟县剖面争取成为国际层面标准剖面的竞争力受到影响.近期,随着锆石SHRIMP年龄测定技术在华北古陆前寒武纪地层学研究中的成功应用,在几个关键层位定年研究中取得实质性进展.北京西山下马岭组中部班脱凝灰岩中获得锆石SHRIMP加权平均年龄为(1370±11)Ma,使得下马岭组这个青白口群的关键地层单位划归为中元古界.天津蓟县大红峪组碱性火山岩中获得锆石SHRIMP加权平均年龄为(1625.9±8.9)Ma.可用于标定华北古陆中元古代裂解时间得北京密云环斑花岗岩获得锆石SHRIMP加权平均年龄为(1685±15)Ma.这些SHRIMP测年结果使华北古陆中、新元古界年代地层划分与全球对比有了年龄"锚点",必定有利于准确厘定华北地区中、新元古界的内涵.由于华北蓟县中、新元占界剖面是我国晚前寒武纪地层的标准剖面,因此上述年代地层框架的优化对于我国地质填图的修正和精确地层对比有着重要的促进作用.同时,对于我国前寒武纪生物演化,特别是宏观藻类发育的时间研究具有重要意义.这必定有助于提升华北中、新元古界剖面的国际地位.

The Ynashan sedimentary basin of Changchengian (1800-1400Ma) of the Mid-Proterozoic is located in North China. Sedimental accumulations of the basin were first one with nature of the covering strata after formation of the crystalline basement of the Archaeozoic-Early Proterozoic.The sedimentary environmental evolutions are described as follows:axial river-fans and braid rivers in alluvial environments,sandy tidal-shallow shoal or bar in marine,mud and carbonate tidal or lagoon in the early Changchengian;and debris-carbonate tidal or shoal with silica from volcanical provenance and fan-dalta,carbonate ringing flatform-slop-basinal facies in the late Changchengian. This shows evolutions of the environmental system from restricted to openning conditions. Alluvial fans, fan-dalta,debris turbidites, carbonate slump breccia,carbonate gravity flow(including grain-flow ), volcanical debris flow and volcanical silica mixed sediments were deposited in the basin. Formation of these facies were controlled by structural action in contemporaneity.Rhythmic shale-micrite carbonates with carbonate dissolution structures and concretion-liked carbonates in the late show the characteristics of deep water carbonate. The sedimentary hydrodynamics of the basin was generally in the condition of mid-low energy due to relatively restricted environments. Framework of the basinal structures consisted of the NE marginal faults and the NW transfer faults. The general longitudal extend and development of the basin were controlled with the Xinglong-Lingyuan fault in the north margin. The vertical of the basin shows a asymmetric shape and main subsidence axis inclines to the north. The basin evolved from narrow half graben to broad downwarp.The facies, environments and structures of the basin were Characteristic of a fail-rift (aulacogen).It showed the process of crust breakup of North China in the early and downwarp subsidence in the late of Changchengian.

燕山长城纪沉积相特征及环境系统反映出坳拉槽盆地的沉积特点?盆内发育着冲积扇?扇三角洲?浊流沉积?碳酸盐滑塌角砾沉积?颗粒流沉积及火山硅质混合沉积等与同沉积构造活动有关的沉积相型?从早期的大陆内部冲积环境到晚期的环边台地─斜坡─碳酸盐深水盆地,环境系统从较封闭状态向半开放方向演化,其演化过程与盆地构造的扩张活动有着密切关系的?

Intense tectonic deformations in Mesozoic occurred in the Yanshan area in North China, which influenced the tectonic configuration of the whole area. Some important progresses were obtained in the study of Mesozoic tectonics and their associated basin systems in recent years, and at the same time different understandings about the tectonic events of the area also appear. One of the focuses about the events is whether the movement direction of the Late Jurassic thrusting was generally from the north to the south or from the south to the north, and what its scale of displacement in horizontal is. This understanding involves the way of tectonicactivity and its geodynamic background in the Yanshan area during that time. The Chengde area is a typical location to examine the direction of the Late Jurassic structural displacement. Two conflicting understandings have been proposed for the main thrust movement direction and its scale in the Late Jurassic. One is that the direction of thrusting was generally from the north to the south, and formed piggyback basins associated with southward propagating thrusting faults. The other suggests that the direction of thrust faulting was generally from the south to the north, and a block ("thrust plate") bounded by two roughly E-W trending thrust faults, the Shuangmiao fault on the north and the Jiyuqing fault on the south, between Chengde city and Chengde county, was a Late Jurassic exotic "Chengde thrust plate" formed in a low-angle northward thrust faulting, and its thrust distance is more than 40 km. The Shuangmiao thrust fault has been interpreted as a zone constituting the north limb of the "thrust plate". A study of the original sedimentary characteristic, lithofacies distribution, sequences and thickness of the Mesoproterozoic Changchengian strata shows that the strata involved in the interior of the so-call "Chengde thrust plate" are similar to the closed outside about 2 km from the "thrust plate", but different from a hypothetical "root belt" in the Kuancheng area, 40, km or more southwards far away. Additional evidences that the present Mesozoic basins still keep their relatively complete outline in shape are from geological maps and our fieldwork, which indicate the continuity of Mesozoic sedimentary strata, geological boundary lines and even faults in the Chengde area. That the Changchengian lithofacies configuration was not destroyed demonstrate that no obvious change took place in the Mesozoic structural deformation, and the possibility of large-scale horizontal displacement (>40 km) from the south to the north in the Late Jurassic is very small. Therefore, this study does not support the interpretation of large-scale external "thrust plate" in the Chengde area. We interpret that the Shuangmiao thrust fault as a back thrust played a role of accommodation fault due to the late Jurassic southward thrusting on the Jiyuqing fault, and it was reactivated again after the Jurassic.

外来岩片不但在构造变形上应具有显著的特征标志,而且在其卷入的各类地质体中也应该表现出与原地系统之间具有明显的差异.近年来,承德地区两条断裂之间所夹地质体,被部分学者认为是晚侏罗世时期从该地区南部向北推覆而来的"逆掩片",水平位移量超过40km.本文对比研究了"逆掩片"内部和"根带区"中元古代长城系原始沉积特征和相带展布以及其他证据,发现承德地区长城系各相带原始展布和格局与周边同期沉积并无显著差别,这表明晚侏罗世期间发生自南向北大规模水平位移(＞40km)的可能性很小,研究结果不支持"外来岩片"的认识.

The principal part of the Middle-Late Proterozoic Yanshan Rift Basin is located in Hebei and Liaoning provinces of North China. An obvious rifting of the Yanshan Basin occurred in the early stage of the Middle Proterozoic, named Changchengian about 1800-1400Ma. Sedimentary fills of the basin during this period are earliest deposits within the covering strata after formation of the crystalline basement of the Archaeozoic-Early Proterozoic.The Changchengian of the early Middle Proterozoic mainly consists of five Formations, namely, Changzhougou, Chuanlinggou, Tuanshanzi, Dahongyu and Gaoyuzhuang Formations.During the Changchengian the palaeotectonic activities of the basin controlled the basin fillings in four ways, that is, synsedimentary faulting, structural tilting, and intent subsidence in basin axis and equilibrium subsidence in entire basin. In particular, the synsedimentary faulting, characterized by abrupt or pulsing activities, controls the distribution of main facies belts of the basin. During the intense periods of the basin, the synsedimentary faulting also caused a series of event depositions, such as palaeo-seismic records, carbonate slumping, clastic turbidites, and volcanism-induced volcanic turbidite deposits. Analyses of palaeocurrent, stratigraphic framework, and special facies belts show that the main axis of the basin is along NE direction. The outlet position, towards open sea, of the intracontinental rift basin probably was located in the north part of the Sino-Korea Paraplatform and the basin infilling during the Changchengian was not obviously affected with the E-W direction (from Chicheng to Beipiao) faulting.

在早期长城纪演化阶段，燕山中晚元古代裂谷盆地构造拉张活动明显，它控制了整体沉积相带的展布，并在强烈活动期引发了一系列事件沉积。长城纪时期的古构造活动主要以四种方式影响盆地的充填，其中同沉积断裂活动在长城纪盆地演化过程中具有突发性或脉动活动的特点，记录了古地震、碳酸盐滑塌沉积、碎屑浊流沉积，并诱发火山活动形成火山碎屑重力流等地质事件。盆地的古水流、地层格架及特征沉积相带等分析显示，盆地主体展布为NE向；燕山元古代裂谷向外海出口的位置应处于中朝准地台的北部；现今所赤城—北票EW向断裂在长城纪大部分时期对盆地的沉积充填没有明显影响。

蓟县剖面形成于燕山裂陷槽内,其沉积盆地是在中元古代早期华北原 地台北缘东西向大规模破裂时伸进大陆内部的一支废弃的裂谷基础上发展起来的,它不同于被动大陆边缘,因此不包括陆棚斜坡和大洋盆,而只相当于其中的滨海和 一部分浅海,碳酸盐岩沉积时期则为一个陆表海.盆地的构造性质控制了盆地的沉降特征,在裂陷槽阶段,半地堑式的裂陷控制了沉积体的楔形形态;在过渡阶段, 盆地主要表现为不均衡凹陷;在克拉通盆地阶段,各组的厚度小,岩性和岩相变化也很小,为典型的盖层沉积.盆地的构造性质还直接影响到副层序类型、体系域和 层序界面类型的划分.确定层序界面类型时应抓住大陆架上两种类型层序界面暴露特征的差异,主要是河流回春和河流下切作用是否存在来加以识别和确定.本区不 能划分出典型的凝缩层(段),而最大海泛面表现为由一个或数个加积型副层序组成的最大海泛期沉积物.

摘　要： 与碳酸盐岩地层相似、与地球轨道效应有关的高频率海平面变化旋回在碎屑岩地层中也形成类似的米级旋回层序。这种异成因机制控制下的自旋回沉过程的产物，根据沉积动力机械发为潮汐动力型及波浪动力型，前者以“环境总体向上变浅、颗粒向上变细、岩层向上变薄”的正粒序序列后者以“环境向上变浅、颗粒上向变粗、岩层上向变厚”的反粒序序列为特征，这不同类型的米级旋回层序不但是基本的地层工作单元。而且其有序垂向叠加形式是识别

Different types of meter-scale cyclic sequences in stratigraphical records are the outcomes of episodic accumulation of strata related to Milankovitch cycles. They are marked by particular features of facies-successions resulted from different sediment source and sedimentary dynamics in different paleogeographic background, which become the fundmental rule on the division of meter-scale cyclic sequences. The widespread development in stratigraphic records and the regularly vertical stacking-patterns in long-term sequence, the evolution characters of earth-history and the genetic types reflected by particular fabric features of facies-succession in different paleogeography background, all of these features shows that meter-scale cyclic sequences are not only the fundmental working-unit on stratigraphy and sedimentology but also the replenish and extention of parasequence in sequence stratigraphy.There are generally two kinds of facies-succession for meter-scale cyclic sequcence in neretic-facies strata of carbonates as well as clastic rock, which are normal grading succession mainly formed by tidal sedimentation and inverse grading succession mainly made by wave sedimentation, both of them constitutes generally upward shallowing succession, the thickness of succession is from several tens centimeters to several meters. In terms of fabric features of facies-succession,it can be made the division of genetic types for meter-scale cyclic sequences. Carbonate meter-scale cyclic sequences could be divided into four types,which are L-M type, deep-water asymmetrical type, subtidal type and peritidal type. Clastic meter-scale cyclic sequences could be divided into two types, which are tidal-dynamictype and wave-dynamic type. The boundaries of meter-scale cyclic sequence are marked by instantaneous punctuated surface formed by non-deposition resulted from high-frequence sea-level changes, which include instantaneous exposed punctuated surface and drowned punatuated surface as well as their correlative surface. The development of instantaneous punctuated surface used as the boundary of meter-scale cyclic sequence lead to the limiting of Walthers Law that is used to explain facies distribution in time and space, and reaffirm the importance of Sander's Rule on analysis of stratigraphical records. These noncontinue surfaces could be traced in long distance and some be correlative in same basin range. The study on meter-scale cyclic sequences and their regularly vertical stacking patterns in long-term sequence indicate that the research on cyclicity of stratigraphic records is a useful way to get more regularity from stratigraphic records that are frequently complex as well as non-integratd.

与米兰柯维奇旋回存在成因联系的幕式地层堆积作用的结果,是在地层记录中形成各种类型的米级旋回层序。在不同的古地理背景中,受物质来源及沉积动力学背景的控制,故发育具有不同相序组构的不同类型的米级旋回层序。因此,相序组构特征就成为米级旋回层序类型划分的基本准则。地层记录中米级旋回层序的广泛发育,以及它们在长周期层序中的有序垂直叠加形式和地史演化特征,由不同相序组构所反映的成因类型以及由不同类型所指示的沉积动力背景等等,不但表明了米级旋回层序是描述地层结构的基本工作单元,而且是对“准层序”的延展和补充。在海相地层中,不管是碳酸盐岩还是陆源碎屑岩地层,这种厚几厘米至几米的米级旋回层序,大致都可以划分为正粒序和反粒序两种相序组构,正粒序组构主要是潮汐作用的结果,而反粒序主要是以波浪作用为主的浅海环境的产物 不管是正粒序还是反粒序序列,均构成总体向上变浅序列。由此,碳酸盐岩米级旋回层序可划分为L—M型、深水非对称型、潮下型及环潮坪型 碎屑岩米级旋回层序可划分为潮汐动力型及波浪动力型。米级旋回层序的界面是由高频率海平面变化所产生的非沉积作用面,包括瞬时暴露间断面和瞬时加深淹没间断面乃至它们的相关面,这些在区域上延伸较远,甚至。

here are many silty dykes in peritidal silty muddy shales of the lower part of the Paleoproterozoic Chuanlinggou Formation at Jixian section in Tianjin. Particular configurations on bedding planes and on the surface perpendicular to the bedding planes lead to different explanations for the genesis of these silty dykes:(1)they are considered as the oldest trace fossils of metazoan according to the spindlecrack of siltstones on the bedding plane and the sandfilling tube configurations on the surface perpendicular to the bedding plane;(2)they are considered as the liquefied sandveins induced by earthquake according to the sinuous configuration of siltstone dykes on the surface perpendicular to the bedding plane and the obvious liquation feature. Several features indicate that these silty dykes were generated by the degassing and dewatering processes in the early diagenesis under the condition that the sedimentary surface was sealed by microbial mats， and can further be grouped into the microbial induced sedimentary structure(MISS). These features include:(1)the clear boundary being enriched with residue organic substance and the obvious fluidization feature shown by the relative accumulation of silty grains under the petrographic microscope;(2)the accompanied wrinkle structure and the palimpsest ripples which indicate the development of microbial mats on the sedimentary surface. 

在天津蓟县剖面古元古界串岭沟组下部的环潮坪相粉砂质泥页岩细粒沉积中,发育许多粉砂岩岩墙。由于该粉砂岩岩墙在层面上和层内具有特别的形态,因而对其成因具有多种解释:在层面上呈纺锤状粉砂岩裂缝以及在层内呈砂质充填管形态,从而被认为是最古老的后生动物遗迹化石;在层内呈弯弯曲曲的粉砂岩岩墙以及明显的流体化作用特点,所以又被解释为地震振荡作用形成的液化砂岩脉。显微镜下,这种岩墙具有明显的富残余有机质构成的边界,以及由粉砂颗粒相对聚集所显示出的明显的流体化作用特征;再加上与这种粉砂岩岩墙共生的沉积构造主要是皱饰构造,局部还发育变余波痕,由此表明沉积面上曾经发育过微生物席。因此,这种粉砂岩岩墙应该解释为沉积面在曾经被微生物席封闭的情况下,相对富含有机质的细粒沉积物在早期成岩作用过程中所发生的脱气作用和脱水作用的产物,最终可以归为由微生物形成的沉积构造的一种类型。

In the 1960s, Pettijohn and Potter classified the geologic processes which formed primary structures into erosion, transportation, deposition, and deformation. The primary sedimentary structures are defined as those structures formed by the above processes during sedimentation or after sedimentation while before consolidation. They include various types of bedding, marks on the bedding surface, and deformational phenomena. In their classification on the primary sedimentary structures, stromatolites are defined as positive growth structures projecting from the former depositional surfaces, and are formed by the combined action of microbes and synsedimentary cementation. From the middle 1990s  to the present day, sedimentologists realized that microbes can also form a kind of primary sedimentary structures which do not project from the sedimentary surface, and they are formed by the combined action of microbial mat（or film）and all kinds of physical actions such as erosion, transportation, deposition and deformationThis kind of sedimentary structures are defined as the primary sedimentary structures formed by microbes, which belong to the fifth kind of primary sedimentary structures. Stromatolites were mainly developed in the Precambrian and the Phanerozoic shallow water environments which were not strongly changed by metazoan. Similar to that, the sedimentary structures formed by microbes were also mainly developed in the Precambrian and the tidal flat and lagoon environments in the Phanerozoic which were not strongly changed by metazoan. Therefore, the studies of this kind of sedimentary structures（the fifth kind of primary sedimentary structures） have great significance in the reconstruction of the Precambrian environments. The observation and preliminary study of the primary sedimentary structures formed by microbes in the Mesoproterozoic in Yanshan area provide a useful basis for the further study in the future. These structures include the palimpsest ripple, the wrinkle structure, the microbial sand chip and the spindle crack developed in the Chuanlinggou and Dahongyu formations. They represent the primary sedimentary structures formed by microbes in clastic rocks. The largescale palimpsest ripple and wrinkle structure developed in the nonstromatolitic limestones of the Member 3 of the Gaoyuzhuang Formation represent the primary sedimentary structures formed by microbes in carbonate rocks of the Mesoproterozoic.  

早在上世纪60年代，沉积学家Pettijohn和Potter曾经将形成原生沉积构造的地质作用划分为剥蚀作用、搬运作用、沉积作用和变形作用。在沉积期间和沉积之后到沉积物还未固结之前由上述作用所产生的沉积构造被定义为“原生沉积构造”，包括各种类型的层理、层面上的各种作用痕迹以及各种变形现象。在该分类之中，叠层石被定义为突出沉积面的正生长构造，这种构造由微生物与同沉积胶结作用共同构建而成。上世纪90年代中期至今，随着研究程度的深入，沉积学家们越来越认识到除了叠层石以外，微生物还会形成一种并不突出于底层面的原生沉积构造，并被认为是微生物席或微生物膜与各种物理作用营力共同作用的产物。这些作用营力包括剥蚀作用、搬运作用、沉积作用和变形作用。该类沉积构造被定义为微生物形成的原生沉积构造并被归为第五类原生沉积构造。正如叠层石主要产在前寒武纪以及显生宙未受到后生动物强烈改造的浅水环境中一样，微生物形成的原生沉积构造也主要发育在前寒武纪，以及显生宙的一些未受到后生动物强烈改造的潮坪和潟湖等环境之中。因此，该类沉积构造（第五类原生沉积构造）的研究，对于前寒武纪沉积环境重塑具有重要意义。燕山地区元古界串岭沟组和大红峪组碎屑岩中的变余波痕、皱饰构造和纺锤状裂缝，是碎屑岩中微生物形成的原生沉积构造的代表； 高于庄组第三段非叠层石碳酸盐岩（以灰岩为主）层面上发育大型皱饰构造和变余波痕，是碳酸盐岩中微生物形成的原生沉积构造的代表。这些沉积构造的发现和初步研究，为今后进一步深入研究奠定了良好的基础。

During the Mesoproterozoic, the northern SinoKorean Plate experienced a period of intensive tectonic extension and breakup,thus formed the YanLiao Aulacogen. Abundant palaeoearthquake records has been preserved in the Chuanlinggou and Gaoyuzhuang Formations of the Changcheng System （1800—1400 Ma） and the Wumishan Formation （ 1200 Ma） of the  Jixian System of the Mesoproterozoic. These earthquake records are characterized by various liquefied deformations of soft sediments such as the liquefied sandveins, microspar and coarsespar veins in the carbonate rocks, limestone dike, liquefied breccia, hydroplastic deformation, various curly deformations, loop bedding, graded fault in the interval, and the brittle deformation of the early diagenetic stage. These deformations of earthquake origins are always associated with the synsedimentary faults. Based on the earthquake records and volcanic activities, the SinoKorean Plate experienced at least two episodes of  intraplate breakups. One occurred between 1800—1400 Ma, and the other at about 1200 Ma with the latter one resulting in the formation of the YanLiao Aulacogen. The palaeogeographic framework of the YanLiao Aulacogen  was connected with the two breakups of the SinoKorean Plate. The boundary of the palaeosea basin, the lithofacies zone were both controlled by the contemporary faultearthquake. The palaeoenviroment of the YanLiao Aulacogen was a tectonic zone characterized by deeper material vibrancy, active fault movements, major igneous activities and frequent earthquakes.

位于中朝板块北部的燕辽裂陷槽是中元古代板内裂解的产物。中元古代的伸展裂解构造诱发强地震。中元古代长城系（1800—1400 Ma）的串岭沟组、高于庄组及蓟县系的雾迷山组（1200 Ma）中保留有丰富的地震灾变事件记录：各种软沉积物液化变形，如液化砂岩脉； 碳酸盐岩中的泥亮晶脉、灰岩墙、液化角砾岩、水塑性变形、各种卷曲构造、环形层、层内粒序断层以及碳酸盐岩成岩初期的脆性变形。这些地震成因的变形构造与同沉积断裂相伴生。依据地震记录，中朝板块北部地区中元古代经历两次板内裂解，即1800—1400 Ma之间与1200 Ma，200 Ma的裂解导致燕辽裂陷槽的最终形成。燕辽裂陷槽中元古代的古地理格局与两次板内裂解相联系，古海盆的范围、盆地的边界、岩相带均受同时期断裂—地震控制。燕辽裂陷槽的古地理环境是一个深部物质活跃、断裂火山活动剧烈和地震频繁的构造带。

中国北方燕辽裂陷槽位于中朝板块北部,是巨厚中、新元古界的沉积区.中、新元古界包括长城系(1800～1600 Ma)、蓟县系(1400～1000 Ma)和青白口系(1000～800 Ma).上述划分是中国地质学家长期研究的共识,由全国地层委员会发布,中国地质调查局在全国地质调查填图中施行[1].青白口系自下而上包括下马岭组、龙山组、景儿峪组,由于在下马岭组的斑脱岩中获得了锆石SHRIMP U-Pb年龄1368Ma±12Ma,从而对1000 Ma作为青白口系底界的年龄乃至中国中、新元古界地质年表提出了挑战.中国地质学家必须面对新的下马岭组年龄值,拼弃传统思维,重新排定北方中、新元古界年代地层柱中各系、组的界线年龄.本文建议:长城系为1800～1600 Ma;蓟县系为1600～1400 Ma;新建西山系为1400～1200 Ma;1200～1000 Ma是一个待命名的系;新的青白口系为1000～800 Ma,包括龙山组及景儿峪组.由于下马岭组中的斑脱岩反映了岛弧构造环境,从而可重塑中朝板块北部下马岭组及整个中元古界(指1800～1200 Ma)为沟-弧-盆板块体系的弧后扩张盆地,即传统概念中的燕辽裂陷槽是弧后扩张的产物.沟-弧-盆板块体系可以系统地解释燕辽裂陷槽的动力学成因、各种地震灾变事件、火山活动、层控矿床等形成的地质背景. 城系为1800～1600 Ma;蓟县系为1600～1400 Ma;新建西山系为1400～1200 Ma;1200～1000 Ma是一个待命名的系;新的青白口系为1000～800 Ma,包括龙山组及景儿峪组.由于下马岭组中的斑脱岩反映了岛弧构造环境,从而可重塑中朝板块北部下马岭组及整个中元古界(指1800～1200 Ma)为沟-弧-盆板块体系的弧后扩张盆地,即传统概念中的燕辽裂陷槽是弧后扩张的 物.沟-弧-盆板块体系可以系统地解释燕辽裂陷槽的动力学成因、各种地震灾变事件、火山活动、层控矿床等形成的地质背景. 城系为1800～1600 Ma;蓟县系为1600～1400 Ma;新建西山系为1400～1200 Ma;1200～1000 Ma是一个待命名的系;新的青白口系为1000～800 Ma,包括龙山组及景儿峪组.由于下马岭组中的斑脱岩反映了岛弧构造环境,从而可重塑中朝板块北部下马岭组及整个中元古界(指18

北京十三陵地区中元古界长城系 包括5个组:常州沟组、串岭沟组、团山子组、大红峪组和高于庄组,前2个组主要由碎屑岩组成,后3个组主要由碳酸盐岩组成。众多的沉积相标志反映:常州沟 组属于滨浅海碎屑岩沉积环境;从串岭沟组开始,其沉积环境向碳酸盐岩沉积环境过渡;后3个组沉积时的环境为典型的陆表海碳酸盐岩沉积环境。在综合研究的基 础上建立了沉积环境模式。另外,长城系还有许多特殊的沉积现象值得进一步研究和讨论:世界上最古老的宇宙球粒;高于庄组白云岩层面上双脊波痕的内碎屑颗粒 成因和硅化白云岩内青鱼骨状层理及硅质团粒的成因;特别是在大红峪组首次发现太阳星云物质——碳质球粒陨石。

根据底砾岩的砾石成分、结构、分布、产状及沉积相序等特征,将燕山中段常州沟组底砾岩分为冲积扇沉积、河流沉积、扇三角洲沉积、海滩沉积等4种成因类型,并探讨了常州沟早期燕山盆地的岩相古地理格局.

The Chuanlinggou Formation(ca 17 Ga)is characterized by dark shale and is widespread in the North China Platform， with a thickness up to 900 m. In this formation abundant centimeterscaled pygmatic sandveins are well developed. They have been interpreted as deriving from the sand filled fissures created by biogenic gas release. In the sandveins minor amounts of authigenic carbonate precipitation(ACP)and pyrites have been identified . The ACP is mainly of crypto-to microcrystalline dolomites， occurring either as horizontally continuous seams or as discrete spots， often accompanied with organicrich lamina. The ACP seams generally occur at the places where biofilms densely concentrated， and tend to extend along the biofilms. In contrast, the ACP spots prefer to exist in intergrain pores as cryptocrystalline cements or along the outer margins of sandveins as microcrystalline dolomites. These two types of ACP have been recognized both in the sandveins and host sediments. The associated  framboidal pyrites are more abundant in mud sediments. while rimmed pyrite crystals in the sandveins. Siderite crystals also exist in the sandveins. These minerals are often associated with ACP forming characteristic fabrics， along with the organicrich shale and well developed microbially induced sedimentary structures(MISS)， suggesting an anoxic environment for the Chuanlinggou deposition. Analyses of the morphology and rheology of the sandveins and their distribution in relation to the dark shale suggest that they were derived from the fissures created by gas release as passages and subsequently filled by stormtransported sands. The gas release origin is also supported by the existence of gas blisters(MISS)on sedimentary surfaces. The coexistence of ACP and authigenic pyrites and their preferential occurrence in the sandveins indicate that they resulted from the anaerobic oxidation of methane(AOM)and bacterial sulfate reduction(BSR)happened in a sulfatemethane transition zone(SMTZ)few centimeters below the sedimentary surface. The recognition of putative microbial fossils in the sandveins and the biomarkers indicative of archaea and sulfur bacteria from the dark shale may also provide evidence for AOM. Methane might derive from anaerobic degradation of buried organic matter， with part from the possible methanogenesis as well. The recognition of ACP and AOM in the Chuanlinggou Formation is of significant implications for the Mesoproterozoic plaeoclimate and paleoceanographic analyses. With a low seawater sulfate concentration and therefore a shallow SMTZ during the Mesoproterozoic ocean， the consumption of methane by AOM would be proportionally lower than that in the modern marine environments. As a result， the methane fluxed into the atmosphere would inevitably increase the relative importance of methane in maintaining the Mesoproterozoic greenhouse climate.

华北中元古界串岭沟组暗色页岩中普遍发育的砂脉构造被解释为气体逃逸形成的沉积构造。在砂脉和相邻围岩中发现有自生碳酸盐沉淀和自生黄铁矿。自生碳酸盐主要由白云石组成，表现为微晶质条带或隐晶质斑块状胶结物。微晶白云石条带多出现在有机质纹层密集发育的部位，沿微生物膜两侧发育；而隐晶质斑块多以胶结物形式充填粒间孔隙或沿砂脉外缘密集产出。围岩中共生草莓状黄铁矿，砂脉中有具环带黄铁矿。这种特殊的矿物组构以及富有机质沉积和丰富的微生物成因构造(MISS)均表明串岭沟组形成于缺氧环境。层面发育的气泡构造为砂脉的气体逃逸成因提供了支持，而自生碳酸盐和黄铁矿则是沉积浅层硫酸盐—甲烷转换带(SMTZ)甲烷厌氧氧化(AOM)和细菌硫酸盐还原(BSR)的产物；气体源于有机质的厌氧分解和甲烷菌活动。砂脉中发现有疑似微生物化石，围岩含古菌和硫细菌生物标志物，表明有发生AOM和BSR作用的条件。串岭沟组砂脉中识别的自生碳酸盐沉淀及其AOM成因对进一步认识中元古代古海洋与古气候条件具有重要意义。由于海洋的低硫酸盐浓度，SMTZ带很浅，海底沉积层的甲烷仅少量被AOM消耗；而大量甲烷进入大气必然导致中元古代强烈的温室气候效应。

华北克拉通中元古代长城系盖层广泛分布, 其沉积时代和物质来源对于华北克拉通前寒武纪地壳演化研究具有重要意义. 本文报道了北京十三陵地区华北克拉通长城系盖层碎屑沉积岩碎屑锆石年龄分布模式. 样品为长城系下部常州沟组含长石石英砂岩(CHc-2)和石英砂岩(CHc-9). 碎屑锆石年龄主要分布在2.35~2.60 Ga之间, 靠上部层位(CHc-9)还有一定数量1.9~1.8 Ga和2.1~2.3 Ga碎屑锆石存在. 研究表明, 碎屑沉积物来自以约2.5 Ga陆壳物质为主的华北克拉通物源区, 1.9~1.8 Ga为华北克拉通古元古代哥伦比亚超大陆陆-陆碰撞构造热事件响应的年龄, 长城系盖层最大沉积年龄小于1.8 Ga.

摘　要： 以蓟县剖面为代表的燕山地区长城系，按照我国现行的地层划分，自下而上包括常州沟、串岭沟、 团山子、大红峪和高于庄5个组，总厚4283m，时限约为1800-1400Ma。新的研究结果表明：1）在高于庄组与下伏“大红峪组”之间不仅存在清楚 的区域性假整合界面，而且在燕山东部的青龙一迁西地区还存在两层底砾岩，分别代表青龙上升的主幕（下砾岩层）和第二幕（上砾岩层）；2）这两砾岩层之间的 地层为上、下假整合所限，理应建一新的组一级岩石地层单位，建议称“马蹄峪组”；3）马蹄峪组的底砾岩，不仅规模大，而且其上还有陆相（洪积、冲积）沉 积，因而其下是一个I类层序不整合界线（SB1），若以它为界，长城系可分为两个对应的一级沉积旋回和层序、两个性质完全不同的盆地沉积（下部为裂陷槽沉 积和上部是陆表海碳酸盐沉积）和两个面貌不同的生物群落；4）根据当前的同位素年龄资料，马蹄峪组与下伏大红峪组的界线或青龙上升主幕的年龄约为 1600Ma，与上覆高于庄组的界线约为1500Ma，因此燕山长城系内的青龙上升也正是对主要发生在1600～1500Ma之间的全球性地壳运动的响 应。根据上述新资料，建议以马蹄峪组与下伏大红峪组的假整合界线或青龙上升主幕为界，将长城系分为两个群一级岩石地层单位，即长城群 （1800-1600Ma）和高于庄群（1600-1400Ma），两群界线的年龄约为1600Ma。此外，原蓟县高于庄组之下的4个亚组，根据它们各自 的沉积特征、岩性差别、区域上的稳定分布等特点，建议将它们各自提升为组。如是这样，上述对原长城系新的划分建议不仅能更好地反应原长城纪时期 （1800-1600Ma）古燕山盆地的构造、沉积、生物等方面演化发展的阶段性特征，而且也更有利于与国内外相关地层的对比。