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1.
The carbon isotopic characteristics of dinosaur eggshell fossils in Late Cretaceous from Xixia Basin and their significance 总被引：2，自引：0，他引：2
This paper studies the Late Cretaceous dinosaur eggshell fossils from the Xixia Basin,Henan Province,by icroscopy and carbon isotope method.Careful observation under microscope revealed that all dinosaur eggshell fossils consist of primary calcite and secondary calcite.The content of the former is about 60.5% and the latter 39.5% according to image analysis.The δ13C values of secondary carbonate mineral filling within the dinosaur eggs in the strata range from-5.63‰ to -5.68‰,with an average value of -5.64‰,the δ^13 C values of sixteen dinosaur eggshell fossils are in the range from-5.88‰ to -7.79‰,Then we calculated the δ^13 C values of primary carbonate minerals,ranging from-6.03‰ to-9.19‰.Bsed on the δ^13C values of the primary carbonate ,the ancient food type and food proportion of dinosaurs were deduced.The dinosaru‘s food proportions of C3 plant and C4 plant are 61% and 39%,respectively.Finally,it is inferred that the palaeoclimate in the Xixia Basin should be a warm-sub-humid-sub-arid climate in the subtropical zone of the Xixia Basin. 相似文献
2.
In this study, field measurements were made and environmental isotopes and radiological properties were determined in six selected wells located in the coastal area south of Beirut, the capital of Lebanon. It is one of the many district areas in Lebanon, threatened by the penetration of seawater into aquifers. Two sampling campaigns were carried out to determine possible seasonal variations. High electrical conductivity was observed, ranging from 1080 to 7900 μS/cm. The total dissolved solids values ranged from 530 to 5600 mg/L. This is attributed to a seawater intrusion confirmed by high chlorine concentrations that ranged from 400 to 3500 mg/L. Isotope data for δ18O/δ2H showed enrichment that is relatively small at the end of wet season due to recharge by local precipitation and infiltration. Carbon-14 ages and 234U/238U ratios confirmed the presence of young water. No radiological hazard was observed as all values lay below the guidance levels of the WHO. 相似文献
3.
安徽齐云山晚白垩世恐龙蛋矿物和元素组成及古环境分析 总被引：1，自引：0，他引：1
安徽齐云山新发现的恐龙蛋化石保存完好,是研究该地区晚白垩世恐龙动物群生活环境及绝灭的关键。本文采用粉晶X射线衍射法(XRD)、电感耦合等离子体发射光谱/质谱法(ICP-OES/MS)分析齐云山恐龙蛋壳、蛋核及围岩的宏观矿物及主量、微量元素组成,以探讨齐云山晚白垩世古环境和古气候特征。结果表明:恐龙蛋壳主要矿物组成为方解石和石英,且蛋内外物质矿物组成相似,主要为石英和长石;而元素组成包括常量元素Ca、Na、Mg、K、Al和Fe及微量元素Sr、Zn、Ba、As、Ti、V、Cr、Co、Ni、Cu、Mn、Pb、La、U和Ir,其中Sr在蛋壳中含量的平均值为6199.3×10~(-6),高于河南西峡及广东南雄大部分恐龙蛋壳中的Sr含量,蛋壳中Ir含量的平均值为59.6×10~(-12),Sr和Ir与背景值相比均有明显异常,分析认为是恐龙与外界进行物质交换时吸收有害元素引起的。而As、Mn和Pb的富集及Zn的不足可能使恐龙机体中毒进而灭绝。围岩中Fe含量的增加表明齐云山地区晚白垩世为干旱炎热的气候条件,与Fe呈正相关性的Ir元素随Fe含量的增加而富集,且越靠近K/T界线,围岩中Sr和Ir元素含量越高,这是导致该地区恐龙动物群绝灭的原因之一。此结论为研究齐云山地区恐龙动物群的生活环境提供了依据。 相似文献
4.
In Sung Paik Min Huh Kye Hun Park Koo Geun Hwang Kyung Sik Kim Hyun Joo Kim 《Journal of Asian Earth Sciences》2006,28(4-6):457-468
Eighty two dinosaur trackways were newly discovered in Upper Cretaceous lacustrine deposits on islands in the vicinity of Yeosu, Korea. Most dinosaur tracks occur in marginal lake deposits with polygonal desiccation cracks. The dinosaur tracks at the Yeosu site include 65 ornithopod trackways, 16 theropod trackways and one sauropod trackway. The prevalence of ornithopod tracks and the limited occurrence of sauropod tracks at the Yeosu site evidently reflect decreased sauropod diversity in the Upper Cretaceous. All ornithopod trackways represent bipeds, and most of the ornithopod tracks are similar to Caririchnium from other sites of the Korean peninsula. All fossil wood specimens collected in the study area represent conifers (three species of cupressaceous and two species of taxodiaceous conifers, and a new species) except for one, which is a discotyledon. It is thus inferred that the southwestern part of the Korean Peninsula was primarily covered with mesic forests with taxodiaceous trees during the Late Cretaceous. The K–Ar age of the Yeosu tracksite is determined as 81–65 Ma (Camapnian to Maastrichtian). It indicates that the Yeosu track site contains the last records of dinosaurs living in Asia. Consequently, semi-arid palaeoclimatic conditions, together with a large lake as a persistent water source and rich vegetation of gymnosperm trees as food, resulted in the preservation of abundant dinosaur tracks in the Upper Cretaceous on the Korean Peninsula. 相似文献
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6.
广东南雄白垩系及恐龙蛋到鸟蛋演化研究 总被引：3，自引：1，他引：2
首次实测了南雄盆地一条完整的白垩系剖面;沿剖面在66个层位中采集到蛋化石, 新建了1个恐龙蛋科, 2个属及6个种;在厘定南雄盆地和丹霞盆地的岩石地层后, 统一提出了一套白垩纪地层单位名称。另外通过对羽状蛋化石的研究, 揭示出恐龙蛋到鸟蛋的进化, 是由于蛋壳棱柱层产生了变异, 出现了从‘层状结构’到‘羽状结构’的转变;与现代鸟禽类对比后确认, 恐龙蛋的棱柱层相当于鸟禽类的鳞片层(带);具有羽状结构的蛋化石是恐龙蛋演化到鸟蛋的一种中间类型。 相似文献
7.
Based on geomorphologic and hydrogeologic characteristics of its territory, Lebanon is divided into three provinces: the West Lebanon province, the Bekaa province, and the East Anti-Lebanon province. These provinces are subdivided into smaller hydrogeologic units, the basins and subbasins. Significant features used in the subdivision are faults, relief, anticlinal axes, river channels, and water divides. Recharge to groundwater is a percentage of the intake area, the percipitation rate over this area, and the infiltration rate of outcropping rocks. The amounts of recharged water over the three provinces are 1609, 914, and 19 Mm3, respectively. Discharge is surface water from springs and water wells along the Lebanese coast. The discharge from the Lebanese rivers exceeds 3700 Mm3/year, an appreciable amount of which comes from natural springs. The quantity of groundwater pumped by wells or flowing into neighboring countries and to the sea as submarine springs, may exceed 800 Mm3/year. 相似文献
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Graciela Delvene Rafael P. Lozano Martin Munt Rafael Royo-Torres Alberto Cobos Luis Alcalá 《Proceedings of the Geologists' Association. Geologists' Association》2019,130(1):87-102
Bivalves from the Late Jurassic and Early Cretaceous stratigraphic section at Las Zabacheras (Galve Sub-basin Teruel, northern Spain), are reviewed from both systematic and palaeoautoecological perspectives. For this study the Villar del Arzobispo Formation, well known for important dinosaur occurrences, was sampled from the boundary with the underlying Higueruelas Formation (Late Jurassic), to the first levels of the overlying El Castellar Formation (Early Cretaceous). The bivalve taxa have Late Jurassic affinity, pointing to a possible Jurassic-Cretaceous boundary towards the top of the Villar del Arzobispo Formation. We have sampled oncoids, whose nuclei are bivalves, through the section to study environment change in this lithostratigraphical formation. Geochemical trace elements and δ13C and δ18O stable isotope analysis of the oncoids enable us to determine the conditions in which the microbialites were formed and provide further palaeoenvironmental data from the deposits containing the bivalves. Bivalve taxa change from the lower part of the Villar del Arzobispo Formation, where Ceratomya excentrica and Unicardium cf. subregulare are characteristic of marine conditions, becoming more continental towards the top of the formation with the presence of Unionoidean bivalves, and in the “Wealden” facies of the El Castellar Formation, where Teruella gautieri, has been found. Bivalves and oncoids allow us to recognize continental conditions where the first dinosaur of Spain, the sauropod Aragosaurus ischiatus was found, in an open water system, where there was limited evaporation, and with enough energy to produce well oxygenated water. 相似文献
10.
河南西峡晚白垩世恐龙蛋化石壳超高异常Sr的发现及其意义 总被引：5，自引：0，他引：5
利用电感耦合等离子体发射光谱仪(ICP-AES),对采自河南西峡晚白垩世的十三枚恐龙蛋化石壳及蛋内充填物和部分围岩进行了测试。发现Sr元素具有明显的超高异常。恐龙蛋化石壳中的Sr的含量分布在1962×10-6～11010×10-6之间,平均5532×10-6,比古代和现代富Sr的腕足类外壳高一到数倍,比地壳丰度值高一个数量级还多。这种超高异常可能与恐龙蛋壳中含有一定数量的文石有关。而由于文石稳定性较差,在石化过程中会逐渐向低镁方解石转化,所以现在已无法再见到蛋壳中的文石,但Sr却保留了下来。反映了中生代时陆生爬行动物的蛋壳与海相生物硬壳一样具有文石和方解石共存的局面。 相似文献
11.
刘宗文 《沉积与特提斯地质》1990,10(3):34-41
近年来四川盆地不断发现恐龙化石,引起人们极大关注。本文以四川省安岳县最新发现的恐龙动物群埋藏特征,初步探讨其环境意义。一、安岳恐龙化石埋藏特征已发现的安岳恐龙化石均埋藏在侏罗系上统上部地层中(图1)。我们重点对顶部马蹄寺和隆家崖化石点进行了发掘。 相似文献
12.
Calcitized Jurassic dolostones from central Mount Lebanon (Kesrouane Formation) are discussed utilizing petrographic, mineralogical and geochemical data. In particular, two sequential extraction methods for both major/trace elements and stable isotope analyses provide results that support and refine conventional bulk analyses data. The new data demonstrate that the major dedolomitization phase of the investigated Jurassic carbonates occurred as a result of the migration of karst‐related meteoric waters (characterized by soil‐derived carbon, and estimated δ18OV‐SMOW composition between ?7·2‰ and ?3·4‰) into previously dolomitized horizons within the limestone rock, during the final uplift and emergence of Mount Lebanon, after Palaeogene time. The study demonstrates that, in this case, the mechanisms of dedolomitization and their resulting fabrics are controlled primarily by the texture of the original dolomite rock. Pervasively dolomitized rocks, where the micritic matrix is entirely dolomitized, show calcitization mainly through dissolution/precipitation. By contrast, the rock textures that still include a considerable amount of limey micritic matrix – spared from dolomitization – are more prone to mole per mole and mimic replacement of the dolomite crystals by calcite. 相似文献
13.
The paper describes the variation pattern of magnetic susceptibility of Lameta sediments and isotopic variation of organic13C from Chui Hill, Bergi, Kholdoda, Pisdura and Girad. The susceptibility pattern and a negative carbon isotopic anomaly allows
fixation of the K/T boundary at these localities and they differ in these aspects from the inter-trappean sediments at Anjar.
Paleomagnetic measurements of the Anjar sediment and the overlying basalt flow demonstrate reversed polarity. The Lameta sediments
with dinosaur nests at Kheda and the overlying intertrappean sediments are of normal polarity.
The clay layers at Anjar, associated closely with Ir-enrichments, are strongly leached, rhyolitic bentonites containing low-quartz
paramorphs after high-quartz with glass inclusions.
It is concluded, that the inter-trappean lake deposits at Anjar were deposited in the early part of magnetochron 29R and are
unrelated to the K/T boundary. 相似文献
14.
根据采自内蒙古自治区鄂尔多斯杭锦旗一件恐龙不完整头骨新材料的形态学特征,鉴定其为原角龙未定种(Protoceratops sp.),产出地层为下白垩统。这是原角龙属化石在早白垩世地层中的首次报道,也是该类恐龙在鄂尔多斯地区的首次记录。该化石的发现,扩大了原角龙化石在我国的地理分布范围,也丰富了鄂尔多斯地区恐龙动物群的内容。 相似文献
15.
报道了在宁夏固原首次发现的恐龙足迹化石。该恐龙足迹化石分别为鸟脚类恐龙足迹和蜥脚类恐龙足迹,均发现于早白垩世李洼峡组沉积地层中。其中的鸟脚类恐龙足迹命名为六盘山宁夏足印 ( Ningxiapus liupanshanensis ichnogenus et inchnosp． nov． ) 。六盘山宁夏足印长与宽之比为1. 22; 第I 趾纤细,短于第IV 趾; 第II 趾与第III 趾之间夹角为35°,第III 趾与第IV 趾之间夹角为45° 等特征区别于其他鸟脚类恐龙脚印。新发现的蜥脚类恐龙以足迹化石形式保存,其前、后足印的长度大小分别为36 cm 和15 cm,应为中等大小的蜥脚类恐龙所留下。这些恐龙足迹化石的发现,为研究该地区的古生物地理及古生态的恢复以及为将来在该地区发现恐龙骨骼化石提供重要信息。 相似文献
16.
自从20世纪60年代初在山东诸城发现第一具恐龙骨架“巨型山东龙”以来,一系列具有代表性的恐龙骨骼化石在诸城白垩纪地层中被发现,特别是埋藏于诸城晚白垩世地层中恐龙骨骼化石群,最为引人注目。目前研究发现了包括鸭嘴龙类、角龙类、暴龙类等在内的多种恐龙类型,为丰富我国东部白垩纪恐龙动物群的研究提供了新的宝贵材料。该文系统总结和归纳了近些年来在诸城晚白垩世地层中发现的恐龙骨骼化石及其所代表的恐龙动物群类型的研究成果,同时又提出了目前依然存在的一些亟待解决的关键问题和研究意义,有助于下一步更好的深入研究诸城晚白垩世恐龙动物群。 相似文献
17.
One hundred and forty six dinosaur footprints occur on the Cenomanian outcrop of Fenoliga. They are arranged in six trackways and six footprint groups (a–f). Two basic footprint types can be distinguished: firstly, large circular-elliptical sauropod footprints, forming four trackways (I, III, V, VI) and five footprint groups (a–e), and secondly, smaller, tridactyl theropod footprints forming two trackways (II and IV) and one footprint group (f). Three type specimens, one sauropod and two theropod, were determined during the course of the work. Since no dinosaur bones have been discovered in the Cenomanian rocks of Istria so far, these findings are outstandingly important in the analysis of the regional dinosaur fauna. 相似文献
18.
The North American fossil record of dinosaur eggshells for the Cretaceous is primarily restricted to formations of the middle (Albian–Cenomanian) and uppermost (Campanian–Maastrichtian) stages, with a large gap in the record for intermediate stages. Here we describe a dinosaur eggshell assemblage from a formation that represents an intermediate and poorly fossiliferous stage of the Upper Cretaceous, the Santonian Milk River Formation of southern Alberta, Canada. The Milk River eggshell assemblage contains five eggshell taxa: Continuoolithus, Porituberoolithus, Prismatoolithus, Spheroolithus, and Triprismatoolithus. These ootaxa are most similar to those reported from younger Campanian–Maastrichtian formations of the northern Western Interior than they are to ootaxa reported from older middle Cretaceous formations (i.e., predominantly Macroelongatoolithus). Characteristics of the Milk River ootaxa indicate that they are ascribable to at least one ornithopod and four small theropod species. The taxonomic affinity of the eggshell assemblage is consistent with the dinosaur fauna known based on isolated teeth and fragmentary skeletal remains from the formation, although most ornithischians and large theropods are not represented by eggshell. Relative to the Milk River Formation eggshell, similar oospecies occurring in younger Cretaceous deposits tend to be somewhat thicker, which may reflect an increase in body size of various dinosaur lineages during the Late Cretaceous. 相似文献
19.
西峡盆地晚白垩世红色陆相碎屑岩系地层中（包括高沟组、马家村组、寺沟组）,产有类型多、数量大、成窝性好的恐龙蛋化石。已发现有７科８属１０种。自下而上,恐龙蛋的种类、数量、含蛋层数、蛋窝均大幅度地减少,由高沟组内５科６７种,约１０层含蛋层,至寺沟组内仅存１科１属２种,含蛋层为２层。恐龙绝灭原因的研究,已有３０种以上的学说或观点,但这些观点都不能圆满地解释恐龙的绝灭问题。恐龙的绝灭应该是多因素的,既有地外的灾变,又有地内,生物本身生理的因素。在内、外因等诸因素的共同作用下,恐龙才有可能绝灭。 相似文献
20.
WANG Baopeng LI Jianjun BAI Zhiqiang GAO Junmin DONG Shurong HU Bailin ZHAO Suiqin CHANG Jieqiong 《《地质学报》英文版》2016,90(1):1-18
In recent years, the discoveries of dinosaur footprints have been successively reported from Dianshi Town, Zizhou City, Shaanxi Province. The footprints include the tracks of theropod, ornithopod and sauropod as well. Actually, the dinosaur footprints were found by local inhabitants much earlier in history, but not for science. The slabs bearing the dinosaur footprints were collected for domestic use, such as building stones, millstones, cellar covers, sheepfold fences, windlass holders, etc. This paper is to describe the dinosaur footprints on both sides of three slabs used for cellar covers, sheepfold fences and windlass holders by the local people. 24 dinosaur footprints and 4 trackways have been recognized and all of them belong to theropod. Four kinds of dinosaur footprints are identified, including 1 new ichnogenus and 2 new ichnospecies: (1) Shanbeipus caudatus ichnogen. et ichnosp. nov.; (2) Pengxianpus yulinensis ichnosp. nov.; (3) Eubrontes ichnosp; (4) Kayentapus ichnosp. Dinosaur-footprint-bearing beds were initially identified as the Fuxian Formation of the Lower Jurassic. Multipal dinosaur footprints associated with fragment plant fossils suggest a humid fluvio-lacustrine environment setting in the Ordos Basin during the early period of the Jurassic. 相似文献