关中地区2万年以来黄土序列中蜗牛化石及其有机质的14C AMS测年初探

前人在黄土—古土壤地层的¹⁴C年代学研究中,探讨了不同测年物质的可靠性,但不同物质组分获得的年代差异较大,这是由于选用的样品不符合定年条件,所以选择可靠的样品组分和有效的前处理方法显得尤为重要。对关中地区2万年以来黄土序列中有机质、花粉浓缩物和蜗牛化石进行了AMS¹⁴C年代学研究。运用现生蜗牛壳体的AMS¹⁴C测定来校正化石蜗牛的年龄,结合剖面中孢粉浓缩物、土壤有机质的AMS¹⁴C年代学对比研究,发现蜗牛化石壳体的文石可以提供较可靠的年代数据,为¹⁴C测年的可靠性研究提供了一种可能的途径。     

珠江口盆地渐新统—上新统高分辨率生物地层学研究方法

珠江口盆地第三系的沉积环境按常规可粗略地划分为陆相，过渡相，浅海相和深海相。研究的材料主要是钻井岩屑样品。按每１０ｍ的深度间距，采集每一样品指示不同相的有孔虫，钙质超微化石，沟鞭藻，微形有孔虫和孢粉化石，获得其可比的，定一的丰度五分异度资料。     

贵州瓮安埃迪卡拉系陡山沱组上段底部和下段的遗迹化石

贵州瓮安地区埃迪卡拉系陡山沱组上段产有保存良好的具有生物多样化特征、包含多种门类磷质球粒状化石库的“瓮安生物群”,成为地球早期生物特别是早期后生动物和动物胚胎化石研究的焦点地区。描述了产自瓮安陡山沱组“瓮安生物群”产出层位底部和之下层位的3个后生动物遗迹：Wenganichnus nanbaoensis（ichnogen. et ichnosp. nov.）为具有衬里和半月形回填构造的微弯曲的潜穴管; Doushantuoichnus curvatus（ichnogen. et ichnosp. nov. ）为具有细小横纹脊的中沟和两排呈叠瓦状排列的小羽叶状凸起的表生迹;?Planolites ichnosp. 为任意弯曲的、与围岩岩性略有区别的长线状底迹突起。遗迹化石的形态特征表明它们的造迹生物为沿一定方向运动的、背部与腹部以及前部与后部分化的、两侧对称的蠕虫状后生动物,而非沉积构造。“瓮安生物群”中后生动物的卵和胚胎化石可能系不易保存的软躯体动物的卵和胚胎在水动力作用下与沉积物一起被搬运、沉积,埋藏于较高能浅水环境并处于休眠状态,且被保存。     

中国泥盆纪维管植物的组成与古地理分布

依据泥盆纪早、中、晚3个时期的中国岩相古地理图及中国泥盆纪植物已有的资料,绘制出中国泥盆纪这3个时期的植物古地理分布图。中国泥盆纪海侵的主要方向是从中国西南部的云南地区（早泥盆世）逐渐向长江中游的华中地区（中泥盆世）及长江下游的华东地区（晚泥盆世）发展。中国泥盆纪维管植物在南方的分布是随着海侵,逐渐向华中及华东地区扩展,由早泥盆世西南地区的云南、四川、贵州,以及广西和湖南南部等地区,发展至中泥盆世云南、四川、贵州、湖南的中北部以及湖北的南部地区,在晚泥盆世的分布范围扩大到广东、湖南、湖北、江西、安徽、浙江以及江苏等地区。泥盆纪维管植物在北方的分布范围较小,从中泥盆世才开始出现,主要分布在新疆的北部,晚泥盆世在宁夏等地区也有分布。中国泥盆纪3个时期陆地维管植物各个种类所占的百分含量表明,早期的植物主要以较为原始的莱尼蕨类、工蕨类以及前石松类为主,中期石松类占优势,到了晚期石松类依然占优势,而楔叶类、真蕨类以及前裸子植物开始繁盛。     

广西六景泥盆系腕足壳体的微量元素组成及其对海水信息的保存

低镁方解石腕足化石壳体被广泛地应用于地质历史时期原始海洋地球化学组成的重建研究,其保存度的识别是该研究的一项重要内容。通常使用显微结构、阴极发光和微量元素含量等3种方法验证其对原始地球化学信息的保存,微量元素含量的识别方法一直被置于较为次要的地位。我们对采自广西六景泥盆系腕足化石微量元素研究表明,其Fe、Mn、Sr分别为(12~2800)×10-6、(1~711)×10-6和(243~1835)×10-6。上述3种识别方法实质上都是微量元素的识别,其余两种识别方法只是微量元素的不同表现而已。通过氧同位素组成、Mn和Sr/Mn对比,得知Mn含量小于100×10-6,Sr/Mn值高于10的腕足化石壳体基本上保存完好。这一发现为利用腕足化石研究海水原始碳氧同位素提供了有力的判据。     

Two Early Cretaceous fishes discovered from the most northern area of China: implications for the palaeobiogeography of the Jehol Biota

From a newly discovered Early Cretaceous fossil site at the Sanlianhe Coal Mine in Tahe County, Heilongjiang Province, the most northern area in China, two freshwater fossil fish had been recovered. This paper reports their classifications and implications regarding the palaeobiogeography of the Jehol Biota. The fish assemblage consists of Yanosteus sp. (Acipenseriforms) and Sinamia sp. (Amiiformes). Both are important members of the well known Jehol Biota, and their occurrence supports the correlation of the Yiliekede Formation at Sanlianhe Coal Mine site with the Jiufotang Formation of West Liaoning. The remains of the Yanosteus sp. from this locality is the first known record of the genus other than in the Yan‐Liao area of China, and the specimens of Sinamia sp. is quite similar to what may be a new species of Sinamia from West Liaoning. The new fossil site represents the most northern site that is undoubtedly part of the extent of the Jehol Biota as currently understood. The northern Great Xing'an Range area is an important region that may link correlations between the Early Cretaceous continental biotas of China, Mongolia and Russia. Copyright © 2010 John Wiley & Sons, Ltd.     

中国东北发现似海德堡人头颅化石

科学界普遍认为海德堡人是现代人、尼安德特人以及神秘的"杰尼索娃人"的共同祖先。就在海德堡人发现之后25年,即1933年,中国东北哈尔滨的一位农民被日本军队强征去当劳工,在修建东江桥时发现了1件非常奇怪的人头化石,该化石显得十分粗壮,而且眉骨特别厚。这位农民虽然对海德堡人一无所知,但意识到这件人头化石可能非常珍贵,没有将其交给日本兵,而是偷偷地带回家,包裹好后扔进了自家的水井中,连夜用土将水井封埋。2017年,他的孙子在桂林遇见了季强并讲述了此事,经劝说,将这件人头化石捐献给了河北地质大学,永久性收藏于该校的地球科学博物馆。这件人头化石十分完整,许多形态特征与欧洲发现的海德堡人非常相似。目前,季强正在组建研究团队,对这件珍稀的古人类头颅化石开展研究。研究成果有望改变人们对人类发展历史的认识。     

A preliminary study of natural environmental change and its impact on early Late Paleolithic people in the northeast central Korean Peninsula during Marine Istope Stage 3 (40–30k cal a bp)

We comprehensively analyzed sediments obtained from an archeological excavation. A trench sediment profile of Maedun Cave (MC), South Korea, was analyzed geoarchaeologically. Multi-proxy analyses (palynomorphs, grain size, magnetic susceptibility, animal bones and artifacts) reflected the vegetation, hydroclimate and lives of prehistoric people at Marine Isotope Stage (MIS) 3 (ca. 40–30k cal a bp ) in the early Late Paleolithic. The palynoflora consisted of pollen and non-pollen palynomorphs. Under the air-circulation system in the cave, anemophilous pollen flowed in during the day, whereas waterborne pollen and spores, and freshwater algae, were transported by flooding during the summer monsoon rainy season. Mixed conifer and deciduous broad-leaved forest with an understory of pteridophytes flourished around the north-east central Korean Peninsula during MIS 3. Freshwater algae and grass pollen records may reflect precipitation intensity. It is assumed that they had flowed in during flooding caused by high precipitation during the enhanced East Asian summer monsoon, corresponding to Dansgaard–Oeschger (D/O) events 5 and 8 of δ¹⁸O GISP2 and Hulu Cave. The prehistoric people hunted herbivorous animals in the area around MC and sheltered inside it seasonally. They also used the grains of oats growing near the dwelling as a source of food.