Late Cretaceous (Santonian) Atractosteus (Actinopterygii,Lepisosteidae) remains from Hungary (Iharkút,Bakony Mountains)

Lepisosteid fishes are well known from the Upper Cretaceous of Europe, but only by fragmentary remains from some Cenomanian and Campanian–Maastrichtian deposits. Here we report various cranial and postcranial remains of gars, discovered in the Upper Cretaceous (Santonian) Csehbánya Formation of Iharkút (Bakony Mountains, Hungary). These remains represent one of the most diverse assemblages of lepisosteid fish material from Upper Cretaceous continental deposits of Europe. Based on tooth morphology, scale-microstructure and the features of the supracleithrum we refer these remains to the genus Atractosteus. Besides some uncertain remains from the Cenomanian of France and Spain, the Santonian aged fossils from Iharkút represent the oldest undisputable occurrence of the family Lepisosteidae in the European continental Cretaceous. Using tooth crown morphology, the surface microstructure of the ganoid scales and the anatomy of the supracleithrum a review of the Late Cretaceous lepisosteid record suggests the occurrence of both Atractosteus and Lepisosteus in the European archipelago.     

Amino-acid composition of algal (“stromatolitic”) limestones (Gannat,Massif-Central,France)

The amino-acid compositions of limestones whose origin is thought to be related to the activity of Cyanophyceae have been studied to determine whether the characteristic components of these organisms would be present as geochemical fossils. A significant amount of amino acids is present and the content can be divided between a “free amino-acid fraction” and a “combined amino-acid fraction” containing different amounts of acidic and basic amino acids. There is evidence to suggest that the amino acids and amino sugars isolated are indeed contemporaneous with the formation of the sediments. The absence of diaminopimelic acid and the very small amount of muramic acid present shows that these two important components of algal and bacterial cell-membranes have apparently been extensively degraded.     

华夏龙谱(30)--燕子沟辽宁角龙(Liaoceratops yanzigouensis Xu,Makovicky,Wang,Norell,You,2002)

20 0 2年6月～7月间,十几位中外古生物学者在辽宁省北票市上园镇燕子沟附近中生界义县组底部地层中,发掘出了两具恐龙头骨化石。经研究确定,属于一种新发现的原始角龙类恐龙。研究者为中国科学院古脊椎动物和古人类研究所的徐星、汪筱林、尤海鲁、美国原野博物馆的PeterJ .Makovicky和美国自然历史博物馆的MarkA .Norell ,将这种新发现的小型恐龙命名为“燕子沟辽宁角龙”。角龙类恐龙是恐龙演化历程中最后的和最多样化的代表之一,以植物为食,通常分为两大类:长有颈盾的新角龙类和具有与鹦鹉相似喙部的鹦鹉嘴龙类,它们之间的系统演化关系…     

Photoluminescence of zircon (ZrSiO4) doped with REE3+ (REE = Pr, Sm, Eu, Gd, Dy, Ho, Er)

The photoluminescence properties of synthetic zircon, ZrSiO₄, doped with REE³⁺ (REE = Pr, Sm, Eu, Gd, Dy, Ho, Er) were investigated using combined excitation and emission spectroscopy. All samples showed luminescence characteristics of intra-ion energy transitions, similar to other lanthanide-doped materials. However, the relative intensities were dependent on the energy of excitation and the presence of charge-transfer bands were inferred from excitation spectra. From the data, we conclude that the lanthanides in zircon occur in more than one type of coordination. Energy transfer between different lanthanides was observed in some co-doped samples and emissions that were unassigned in previous studies have been assigned to specific lanthanides based on excitation spectroscopy.     

一次分解试样测定地质样品中~(230)Th,~(232)Th和~(234)U/~(238)U,~(230)Th/~(232)Th

试验了用~(234)Th示踪,一次分解试样测定~(234)Th,~(232)Th和~(234)U/~(238)U,~(230)Th/~(232)Th的快速方法。试样经Na_2O_2熔融分解,并以P350萃取色层法分离铀、钍。然后分别电沉积制备无自吸收铀、钍α源进行α谱测量。本法适用于铀矿石、岩石和土壤试样的测定。     

华夏龙谱(67)——侯氏红山龙(Hongshanosaurus houi You,Xu et Wang,2003)

<正>2003年,中国科学院古脊椎动物与古人类研究所学者尤海鲁、徐星和汪筱林,发表了对产自内蒙古赤峰市附近下白垩统义县组地层的一种新恐龙属种化石的描述。因发现地点位于著名的中国北方新石器时代晚期红山文化分布区,故以此命名属名,种名则以同一研究所学者及化石保管者侯连海命名:侯氏红山龙(Hongshanosaurus houi)。特征:小型素食恐龙。两足行走,上、下颌前端有骨质喙,脸颊两侧有咀嚼用齿列。头骨与鹦鹉嘴龙很像,主要区别是:红山龙的头颅骨比鹦鹉嘴龙低平,眼框椭圆形而非鹦鹉嘴龙的圆形。     

华夏龙谱(60)——始丰天台龙(Tiantaiosaurus sifengensis Dong,et al,2007)

2005年,浙江省天台县街头镇方山村附近白垩系赖家组上部地层发掘出一具恐龙骨架化石,包括12个颈椎,9个背椎,28个尾椎,13条背肋及残缺的骨盆和后肢。虽缺失头骨、荐椎、前肢和脚,但仍是迄今为止浙江发现的最完整的恐龙骨架化石。2007年,中国科学院董枝明和其他有关部门专家     

分散元素(Ge,Cd, Tl)稳定同位素研究

近年来,非传统稳定同位素地球化学得到了飞跃性的发展,其主要研究对象为海洋体系的演化。特别是氧化还原敏感元素(Se,Mo,Fe等)稳定同位素已经在古海洋环境的示踪研究中发挥重要的作用。相比分散元素(Ge,Cd,Tl)稳定同位素研究比较薄弱,但这些元素在海洋体系中有特殊的循环模式,这使得它们的同位素研究将可能存在很大地质潜力。海洋体系中它们的源汇简单,而且有机无机吸附过程都可能导致同位素分馏。Ge,Cd,Tl均属于挥发性元素,原始星云的形成过程可能存在较大的同位素分馏。我国南方大面积的低温成矿域,将为Ge,Cd,Tl稳定同位素的发展提供天然的平台。另外,Cd,Tl是环境污染的主要潜在元素,因此采用稳定同位素示踪还可能示踪表生环境中的污染来源。     

Mineralogical and geochemical studies on the Gowd-e-Morad (Ni,Co, As–Cu) mineral deposit,Anarak (central Iran)

The Ni, Co, As, and Cu deposit of Gowd-e-Morad is located 20 km northwest of Anarak in Central Iran. In this hydrothermal deposit, mineralization occurs as veins in a fault breccia zone hosted by the Chahgorbeh (schist and metabasite) complex. The main ores are made up of Ni, Co, and Cu arsenides. Petrologic studies and results obtained from geochemical analyses have indicated that the Ni, Co, As, and Cu are derived from ultramafic rocks while Pb and Zn are likely to be derived from schist. Based on the geochemical evidence, particularly the high correlation between Ni, Co, and As, it is proposed that this deposit be categorized as a “five elements” mineral deposit. Fluid inclusion studies have shown homogenization temperatures (T_H) in the range 113?206 ?C and salinity 3?13.5 % wt eq. NaCl. Therefore this “five elements” mineral deposit has been determined as a low temperature, epithermal deposit type. It is proposed that the low fluid temperatures are a result of an environment of formation which was distal to a volcanogenic source systems and the major influence of meteoric waters in the hydrothermal system.     

作者索引(37卷,1957年)

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