The microtine distribution and its environmental significance since the Middle Pleistocene in Zhangping Caves of the Qinling Mountains

Three microtine species are recovered from the Zhangping Caves of the Qingling Mountains, namely Microtus oeconomus, Caryomys inez and Caryomys eva. They are climate-sensitive ones with different ecological habits, therefore their distribution well corresponds to environmental variations. Statistical comparison of the distribution of fossil microtines and their counterparts nowadays displays that the climate variation of the studied area and its contiguity since the middle Pleistocene are: warm and humid at 493 ka ago, cool and humid at 259 ka ago―cold and humid at 205 ka ago―cool and humid at 28 ka ago, and warm and dry at present.     

Two new species of Vestrogothia (Phosphatocopina, Crustacea) of Orsten-type preservation from the Upper Cambrian in western Hunan, South China

Although fossils of Orsten-type preservation represented by Skaracarida and Phosphatocopina were first reported from the Middle and Upper Cambrian in western Hunan, South China in 2005, diversified phosphatocopine species have never been appropriately described and elucidated in terms of their evolutionary relationships. Here, we described two new species of Phosphatocopina, Vestrogothia anterispinata sp. nov. and V. bispinata sp. nov. The evolutionary relationship among all the valid species of Phosphatoco...     

Significance of ichnofossils to genetic stratigraphy--Examples from the Cretaceous of Alberta, Canada

Trace fossils represent both sedimentological and paleontological entities, representing a unique blending of potential environmental indicators in the rock record. Trace fossils and trace fossil suites can be employed effectively to aid in the recognition of various discontinuity types and to assist in their genetic interpretation. Ichnology may be employed to resolve surfaces of stratigraphic significance in two main ways: 1) through the identification of discontinuities using substrate-controlled ichnofacies, and 2) through careful analysis of vertical softground (penecontemporaneous) ichnologic successions (analogous to facies successions). Ichnological analysis is a valuable tool in genetic stratigraphic studies. Integrating the data derived from substrate-controlled ichnofacies with paleoecological data from vertical ichnologic successions greatly enhances the recognition and interpretation of a wide variety of stratigraphic surfaces. When this is coupled with conventional facies analysis and sequence stratigraphy, a powerful approach to the interpretation of the rock record is generated.     

山东省虎（Panthera tigris）化石的首次发现及其意义

本文祥详细记述了山东省首次发现的虎化石的特征及出土地点和剖面的基本情况，论证了化石出土地层剖面的时代，应当属于晚更新世，并阐明了该化石发现的意义。     

准噶尔盆地东北缘早石炭世南明水组沉积环境及构造背景分析

准噶尔盆地东北缘发育的下石炭统南明水组沉积岩是对晚古生代北疆地区洋壳俯冲消减作用的沉积响应。本次研究在南明水组地层中发现丰富的遗迹化石:Scalarituba, Planolites,Cosmorhaphe,Spirophycus和Helminthoida。岩性组合特征和遗迹化石所代表的遗迹相,反映了南明水组的主要沉积相类型为扇三角洲前缘、浅海、深海-半深海,从下往上为一个由浅变深再变浅的不对称的完整层序。南明水组的岩性、层序演化以及砂、泥岩地球化学特征表明,该套地层发育的构造背景为弧后盆地。早石炭世准噶尔盆地东部存在的洋壳俯冲消减作用是研究区弧后盆地发育的动力机制。     

黑龙江龙江盆地中侏罗统万宝组时代确定新证据及其地质意义

黑龙江西部大兴安岭地区侏罗纪地层研究程度不高,以往中侏罗世含煤地层的确定主要借助于与吉林西部万宝组的对比。近年来随着新一轮大兴安岭地区含煤及油气地层的区域地质调查工作的开展,笔者在大兴安岭地区中段的龙江盆地（黑龙江省龙江县以西）发现一套新的中侏罗世含煤地层,该地层由砂砾岩和火山碎屑岩夹煤层组成。文中对龙江盆地万宝组火山岩夹层内2件凝灰岩进行了LA-ICP-MS锆石U-Pb定年分析,获得凝灰岩形成时代,其年龄分别为(165.2±1.7) Ma和(162.1±1.6) Ma;笔者采得的植物大化石为Neocalamites Coniopteris Raphaelia组合,时代显示为早-中侏罗世;孢粉化石经初步鉴定,时代倾向于早-中侏罗世;综合同位素年龄及地层古生物研究,笔者认为龙江盆地万宝组的形成时代为中侏罗世晚期。地球化学分析显示：万宝组凝灰岩具有高Si、Al,低Ca、P过铝质钙碱性火山岩特点,富集轻稀土元素,配分曲线呈平缓右倾型,并具有明显负Eu异常;富集大离子亲石元素Cs、Th、U,亏损高场强元素Nb、Ti、Zr,反映火山岩为壳源成因类型。万宝期火山活动可能与古太平洋板块俯冲作用和蒙古-鄂霍茨克缝合带演化双重作用有关,而与蒙古-鄂霍茨克缝合带演化联系更密切。目前中侏罗统万宝组是油气勘探的重要新层系,本研究不仅为大兴安岭东坡地区中侏罗世含煤地层的划分、对比提供同位素年代学和生物地层学依据,而且为龙江盆地形成演化历史及油气资源勘查提供了基础地质新资料。     

北山霍勒扎德盖石炭系扫子山组岩石地层及古孢子化石特征

甘肃山北部霍勒扎德盖地区,分布着一套火山—沉积地层,对其进行岩石地层、区域对比及地层年代等方面的研究,划归扫子山组,并依据组内岩性差异划分为4个岩性段。该组的确定对研究哈萨克斯坦板块南缘地质演化历史有重要意义。     

遗迹化石Rhizocorallium中莓状黄铁矿对古环境古生态的指示--以豫西南上泥盆统为例

豫西南淅川上泥盆统王冠组地层中发育大量与层面平行且具有蹼纹的U形遗迹化石Rhizocorallium。利用环境扫描电镜对Rhizocorallium进行微观观察,发现在其边缘管和蹼纹内部发育大量不同形态的莓状黄铁矿及莓状铁氧化物（单晶为五角十二面体,八面体,立方体和近球形）,与之对应的围岩中仅见少量黄铁矿单晶颗粒。表面具有覆盖膜的莓状黄铁矿大多存在于潜穴内部,其中边缘管中莓状黄铁矿的单晶直径（0.672~1.603 μm,平均直径1.063 μm）较之蹼纹中部的（0.376~0.877 μm,平均直径0.5 μm）的大。上述特征显示出潜穴中莓状黄铁矿的存在可能与硫酸盐类还原菌有关。Rhizocorallium边缘管和蹼纹中高丰度莓状黄铁矿的发现表明:遗迹化石Rhizocorallium可能是造迹者精心构筑的觅食-花园。由于食物供应和氧化还原条件的不同,Rhizocorallium造迹者在其潜穴内部培植不同的微生物,形成一个互利共生的群落。     

Taenidium at the lower Barremian El Hoyo dinosaur tracksite (Teruel,Spain): Assessing palaeoenvironmental conditions for the invertebrate community

An analysis of lower Barremian invertebrate trace fossils at the El Hoyo dinosaur tracksite (Teruel, Spain) was conducted in order to interpret the macrobenthic tracemaker community and the palaeoenvironmental conditions during bioturbation. Abundant bioturbation structures are characterized by meniscate, cylindrical, straight to sinuous, unbranched epichnia, showing the absence of lining, mantle and longitudinal striations. These structures are included in the ichnogenus Taenidium. Burrow width, distance between menisci, type of their fill, and general shape, allow for identification of the ichnospecies Taenidium serpentinum and T. barretti. Dominance to near exclusiveness of Taenidium in the invertebrate trace fossil assemblage suggests assignation to the Scoyenia ichnofacies. This agrees with the presence of vertebrate tracks. Accordingly, a transitional zone between terrestrial and nonmarine aquatic environments, i.e., floodplain areas adjacent to rivers and affected by low energy conditions, could correspond to the El Hoyo site. The pervasive ichnofabric of Taenidium reveals an opportunistic behaviour of the tracemaker, bioturbating rapidly after deposition; bioturbation took place in moist to wet substrates—softgrounds—in shallow tiers, during favourable yet episodic conditions. The opportunistic strategy might owe to a rapid accumulation of nutrients buried within the sediment during alluvial discharges. After bioturbation, minor erosions during fluvial discharges or subaerial exposure may have caused differences in the preservation of the Taenidium.