永善犀牛村沉积赤铁矿简介

受上二叠统宣威组(P2x)含矿层控制.沉积型赤铁矿,矿石品质好,开采条件有利.     

鲁甸县拖麻耐火砖页岩矿特征及找矿标志

云南鲁甸县拖麻耐火砖页岩矿,矿体呈层状、似层状赋存于上二叠统宣威组(P3x)中,矿体延伸稳定,产状与地层产状一致,矿体受层位控制明显,属大陆湖沼相沉积型矿床.上二叠统宣威组为特定的找矿层位,其中矿体底板稳定的紫色凝灰质页岩是重要的找矿标志.     

长江源各拉丹冬一带发现Gallowayinella (虫廷)类动物群

在1:25万赤布张错幅区域地质调查中,于原划下二叠统开心岭石灰岩组中发现晚二叠世长头期Gallowayinella 类动物群化石,表明该区二叠纪地层非属早二叠世,而似应与青海省南部晚二叠世鸟丽群对比.     

塔里木盆地西北缘克孜布拉克剖面下二叠统砂岩沉积构造背景的初步研究

塔里木盆地西北缘的下二叠统由下部的凝灰岩和上部的碎屑浊积岩组成,后者的地球化学特征明显不同于被动大陆边缘沉积,是前渊复理石建造.南天山洋盆经早二叠世的大规模消减后在晚二叠世大部分闭合,相应地,塔北的二叠-三叠系组成了从前渊复理石深海沉积经海陆交互相沉积发育为前陆磨拉石粗碎屑岩的完整序列.     

云南建水荒田铅锌矿床成因分析

铅锌矿赋存于下二叠统灰岩与上二叠统玄武岩之间玄武质、灰质角砾层中,与早二叠世海相火山喷发玄武岩有关的火山沉积—岩浆期后热液叠加改造矿床,后期构造对矿床富集有一定改造作用.     

鄯善县阿其克库都克盆地成煤条件及焦煤远景预测

对阿其克库都克盆地下二叠统成煤地质条件、古气候、古环境及含煤性、煤质特征和远景预测,进行了实地调查和分析研究.经孢粉鉴定和煤质分析,该区煤系地层时代为早二叠世,煤的变质程度已达焦煤阶段.下二叠统煤系地层的发现,在天山地区尚属首次,可作为一个新的成煤时期引起重视.     

广西柳桥地区上二叠统礁灰岩中发现沥青

研究区位于广西扶绥县东门镇和柳桥镇之间,主要分布上二叠统和下三叠统地层.上二叠统包括合山组、上二叠统礁灰岩和大隆组.下三叠统罗楼组由泥岩和灰岩组成.大隆组主要为放射虫硅质岩和泥岩,含有丰富的放射虫、有孔虫、介形虫、菌藻类、腕足类、菊石类和双壳类化石,是好的烃源岩层.礁灰岩具有大量裂隙和孔洞,是好的储集层.在柳桥地区东攀剖面、岜陇剖面和岜料剖面,礁灰岩裂隙和孔洞普遍被沥青充填.研究区上二叠统礁灰岩是值得注意的油气勘探远景区.     

黑龙江伊春红山附近晚二叠世植物群研究的新进展

笔者在伊春红山附近红山组剖面采集了丰富的植物化石.经研究,计有25属58种。大大丰富了前人报道的本组植物化石的内容.分析所获资科,进一步阐述了红山组植物群的组成特征,认为其时代为晚二叠世,而不仅限于晚二叠世晚期.根据过去的化石资料分析.笔者认为“三角山组植物组合”的时代亦为晚二叠世,而不限于晓二叠世早期.在此基础上,本文认为红山组与黄本宏划分的三角山组下部。在岩石组合特征及时代上可以对比.     

新疆南天山缝合带的形成时限 ——来自阔克萨彦岭花岗岩体的锆石年龄新证据

南天山缝合带位于塔里木克拉通与中天山-伊犁-哈萨克斯坦地块之间,其形成时限对于研究古亚洲洋西南缘的南天山洋最终闭合具有重要的意义.利用LA-ICP-MS锆石U-Pb法对南天山阔克萨彦岭地区的花岗岩体进行测试,结果表明花岗岩体的形成时代为早二叠世(273～283Ma),而且大量早二叠世侵入体同时出现在中天山-伊犁-哈萨克斯坦地块和塔里木克拉通.其中,巴雷公蛇绿岩也被早二叠世侵入体所侵入,限定了南天山缝合带的形成时限应早于早二叠世.研究结果进一步支持南天山洋的最终闭合应发生在300Ma之前.     

新甘交界北山地区早二叠世红柳河群的建立

经1:5万区域地质调查研究,北山地区原红柳河组规模巨大,岩性、岩相差异明显,按岩石地层划分原则,应进一步分组.原红柳河组内部有4套岩性、岩相差异较大的岩石组合,以3次砾岩事件和1次火山岩事件为标志,代表了4个不同的沉积阶段,与之对应出现了4个重要的沉积(不整合)界面.依据这4个界面对早二叠世红柳河组进行了重新划分,即下二叠统河西组(P1h)、红柳村组(P1hl)、芦苇井组(P1l)和红柳井组(P1hj).在河西组采集到大量的腕足、苔藓虫等海相动物化石,在芦苇井组第二岩性段含炭粉砂岩中获孢粉化石组合,其时代属于二叠纪.本区新建的4个组实际上是由一个规模较大的老组再分组的结果.按岩石地层单位修定的要求,建议原红柳河组上升为群.     

滇西南澜沧县老厂浅水相“老厂组”时代之订正

对澜沧县老厂水库东侧公路剖面开展系统的生物地层学研究,证实西盟至竹塘公路１３～１４ｋｍ 区段属Ｅｏｓｔａｆｆｅｌｌａ 带,１２．５～１３ｋｍ 区段属Ｐｓｅｕｄｏｓｔａｆｆｅｌｌａ 带。所谓的浅水相“老厂组”和冬瓜林火山岩的时代应修正为早石炭世德坞阶至晚石炭世滑石板阶,宜归入平掌组的范畴。确认老厂矿区存在有两套不同时代、不同构造背景的火山岩     

滇西澜沧老厂晚二叠世双壳动物群的发现及其生物区系特征

本文描述了采自云南澜沧老厂的双壳类,共计13属、15种和未定种(其中1新属、4新种)。该动物群地质时代为晚二叠世,其组成既有鲜明的地方特色,又与扬子地区有明显联系,属扬子生物区系,并具亚热带生物特征。     

Permian biospheric events in Northeast Asia

An analysis of the dynamics of diversity of bivalve species in Northeast Asia in the Permian period allowed us to reveal a number of events when it significantly increased or decreased. Four major mass extinction events were established for bivalves: at the end of the Early Permian, in the Early Capitanian age, at the the Capitanian-Wuchiapingian boundary and at the end of the Late Permian. Along with extinction events, five events of taxonomic radiation/innovation were distinguished: Early Asselian, Middle Kungurian, Early Roadian, Late Wordian, and Early Changhsingian. Revealing of these biotic events has been confirmed by the dynamics of biodiversity in other major groups of Permian fauna (foraminifers, brachiopods, ammonoids). Moreover, they are evidenced in different basins by changes in the character of sedimentation, isotope parameters, eustatic variations and other environmental factors. Most of the events can be traced far beyond Northeast Asia. Their manifestation is associated with general reasons (variations in endogenous regime of the Earth and associated stress effects on the biota). According to this, results of studying these events can be used for global correlations.     

山东淄博晚石炭世双壳类动物群及其古生态特征

本文记述了采自山东淄博地区晚石炭世太原组双壳类化石１５属２８种，讨论了化石组合特征．在研究双壳类动物群的基础上，划分了３个动物群落，即：Ａｃａｎｔｈｏｐｅｃｔｅｎ群落、Ｐａｌａｃｏｌｉｍａ群落和Ａｉｔａｒｔｅｌｌａ群落，并对各群落的生态特征进行了系统研究．     

陆相二叠一三叠系界线划分和事件

我国陆相二叠—三叠系界线的划分主要依据古脊椎动物,孢粉,双壳类、介形虫和古植物等.这些化石组合特征在界线附近都有明显的变化.这种变化不仅可以用来划分界线,而且结合在界线附近其它非生物（沉积物的粒度和颜色等）的异常变化,可以看出在二叠—三叠纪之交曾发生过某种事件.     

Late Olenekian Radiolarians from Bedded Chert of Ashio Terrane, Northeast Japan,and Faunal Turnovers in Western Panthalassa during Early Triassic

Late Olenekian assemblages in the western Panthalassa have been recovered from bedded radiolarian chert sequences of an accretionary complex, the Ashio belt. These faunas are documented and considered in terms of radiolarian diversity and faunal turnover during the latest Permian to Middle Triassic time. The fauna includes 30 radiolarians belonging to Spumellaria or Entactinaria, with two relicts from the Late Permian. This late Olenekian fauna is markedly different from Permian and Asisian faunas, respectively, and is herein named the Minowa fauna. Study of the literaure indicates that radiolarian provinces were significantly disconnected between the western Panthalassa and eastern Tethys during late Olenekian time. Furthermore, 121 of 143 species disappeared during late Olenekian time, and in turn 118 new species appeared in the western Panthalassa around the Olenekian-Anisian boundary. It is concluded that faunal turnover occurred at least three times between the latest Permian and Middle Triassic.The first turnover is the Poalaozoie-type radiolarian extinction at the Permain-Triassic boundary,the second is the diversification of spheroidal Spumellaria and Entactinaria between early and late Olenekian time, and the third is a faunal turnover from the Minowa fauna to the true Mesozoic-type radiolarian famas that are characterized by mulit0segmented Nassellaria.     

班公湖-怒江洋打开时间的地层古生物约束

西藏班公湖-怒江洋的打开时间是争议性较大的科学问题。班公湖-怒江洋两侧的拉萨地块和南羌塘地块的古生物地理和地层层序的对比可以约束班公湖-怒江洋的形成时间。从地层层序上来看,拉萨地块在晚古生代大冰期结束之后是一由碎屑岩到碳酸盐转变的稳定地层序列;而南羌塘地块从早二叠世晚期开始东西向存在较大的相变,西部下二叠统吞龙共巴组之上存在间断面,不整合于上二叠统吉普日阿群之下;而东部下二叠统到中二叠统都是玄武岩和灰岩组成的鲁谷组。古生物地理上,南羌塘地块晚二叠世含有典型暖水的类Palaeofusulina动物群,与拉萨地块形成显著差别;南羌塘地块中二叠世主要的Eopolydiexodina类动物群也与拉萨地块的Nankinella-Chusenella类动物群产生明显差异;再者,南羌塘地块早二叠世晚期的类、珊瑚类和腕足类都呈现明显暖水的特征,但这些动物群在拉萨至今未有报道。综合南羌塘和拉萨地块地层层序、古生物地理特征上的差异,班公湖-怒江洋至少从中二叠世(～269Ma)就已经形成一定的规模。因此,班公湖-怒江洋在中二叠世以前和冰期结束之后的时间段内打开。     

赣中晚二叠世早期鹦鹉螺

本文描述了赣中晚二叠世早期鹦鹉螺５属８种，其中包含有７新种、１新属。本文对江西乐平煤系中的鹦鹉螺，作了简要介绍，该煤系中含鹦鹉螺化石较多，壳体形状直壳和旋卷壳的均有，其中以旋卷壳的鹦鹉螺最为常见，反映旋卷壳鹦鹉螺在晚二叠世早期的鹦鹉螺动物群中占有重要地位     

Adaptive morphologies and guild structure in a high-diversity bivalve fauna from an early Campanian rocky shore, Ivö Klack (Sweden)

The bivalve fauna from a late early Campanian rocky shore at Ivö Klack (southern Sweden), comprises just over sixty species, a very high diversity in comparison to other Late Cretaceous and modern rocky shore bivalve assemblages. This high diversity is here considered to represent a reliable census of the fauna; only in part can it be explained by the cumulative effect of generations of bivalves inhabiting this coastal environment. The high density and diversity and the wide range of shell morphologies allow interpretation of different modes of life in this variable environment with many contrasting habitats. Study of the functional morphology of bivalve shells and comparison with extant relatives has resulted in a subdivision of the fauna into seven guilds and five habitats. The bivalve fauna represents a within-habitat, time-averaged assemblage to which none of the species was introduced from adjacent environments. It includes some of the most northerly known, very small rudistid bivalves, in addition to the oldest known occurrences of Mytilus and Barbatia in association with rocky shores. Bivalves constituted the most important invertebrate group inhabiting the late early Campanian rocky shore at Ivö Klack, in terms of diversity, density and biomass.     

内蒙古阿拉善地区恩格尔乌苏缝合带二叠纪放射虫及其地质意义

报道了采自恩格尔乌苏缝合带的蛇绿混杂岩硅质外来岩块中的二叠纪阿尔拜虫目放射虫化石,包括3属7种,可以划分为2个放射虫化石组合,能够与日本、美国的放射虫化石带进行对比,其地质时代分别为早二叠世和中二叠世晚期-晚二叠世早期。恩格尔乌苏缝合带位于华北板块和塔里木板块之间,这些放射虫化石的发现为研究恩格尔乌苏缝合带的构造演化提供了新的证据。鉴于其中最新的放射虫组合的地质时代为中二叠世晚期-晚二叠世早期,认为华北板块与塔里木板块之间自中二叠世晚期-晚二叠世早期曾经存在古海洋,即华北板块和塔里木板块的拼合时间是晚二叠世晚期。