大别山地区矿化中酸性小岩体地球化学特征     

李振国  黄成新 《华南地质与矿产》2009,(2):42-46

自20世纪五十年代发现河南滦川钼（钨）矿床以来,经几十年勘查研究和对区域水系沉积物测量资料的综合分析,各构造单元元素丰度、富集系数和富集分布特征表明,本区富集元素为Mo,W,Au,Ag,Pb,Cu,Bi,尤其是Mo,W是区内重要的成矿元素。位于华北板块南缘的东秦岭-大别山钼（钨）矿带,是我国重要的钼（钨）矿带之一,钼矿床主要属斑岩型,其次为矽卡岩型、脉型,其成因多与中生代花岗质斑岩有关。本文着重对大别山地区矿化中酸性小岩体的地球化学特征进行总结和论述,以期为该区普查找矿起到借鉴作用。  相似文献   

Subsistence practices in western Mediterranean Europe during the Final Gravettian. Zooarchaeological and taphonomic analysis of faunal remains from level D of Arbreda Cave (Serinyà, NE Iberian Peninsula)     

Isaac Rufí  Lluís Lloveras  Joaquim Soler  Narcís Soler 《第四纪科学杂志》2021,36(3):467-487

During the Final Gravettian, the Reclau Caves (northeast Iberia) were intensively occupied by hunter-gatherer communities. The study of residential level D (c. 25.4–19.7 kyr bp ) of Arbreda Cave offers a new view of subsistence strategies of communities which inhabited the northeast of the Iberian Peninsula, a transition region between the steppe-tundra and the Iberian wooded steppe biomes, during Greenland Stadial 3. Presented here are the results of the zooarchaeological and taphonomic analysis of ungulate and carnivore remains recovered from level D. The study confirms that the faunal assemblage of this level was mainly brought there by humans. The zooarchaeological analysis indicates selective hunting based on the exploitation of familial groups of horses and deer, while other ungulate taxa appear to be infrequent. Hunter-gatherers frequented the site throughout the year, but more intensive use in spring is indicated by subadult sensu lato horses. There was extensive exploitation of ungulate carcasses: various butchery activities, marrow extraction, the use of bone as fuel and ‘less elaborate tools’ are documented. Carnivore canines were exploited to produce ornaments. The great dominance of horses reveals cold conditions and the expansion of open environments related to the chronology span of Greenland Stadial 3.  相似文献   

Controls on spatial and temporal variations in sand delivery to salmonid spawning riffles          下载免费PDF全文

David Milan 《水文研究》2017,31(12):2179-2195

Fine sediment infiltration into gravel interstices is known to be detrimental to incubating salmonid embryos. Infiltration into spawning riffles can show large spatial variations at the scale of a morphological unit and over time, with significant implications for embryo survival. Furthermore, some process‐based infiltration studies, and incubation‐to‐emergence models assume that fines are delivered to redds via suspension rather than bedload. This process‐based 12‐month study examined spatial patterns of predominantly sand infiltration into gravels in an upland trout stream, using infiltration baskets. An assessment of Rouse numbers for infiltrated sand indicated that it was transported predominantly as bedload at flow peaks. Clear temporal and spatial patterns existed, with highest rates of infiltration strongly associated with higher discharges (r² = 0.7, p < .05). Seasonal variations in the delivery of different grain sizes were also a feature, with enhanced contributions of 0.5–2 mm sediment during elevated winter flows and 0.125–0.5 mm sediment during spring and summer; the latter is potentially harmful to the later stages of embryo incubation. Clear spatial patterns were also evident across riffles, with highest rates of infiltration tending to occur in areas of lower relative roughness—the areas competent to transport sand for longer periods. Incubation‐to‐emergence models should take into consideration spatial patterns of fine sediment dynamics at the pool–riffle scale, to improve prediction.  相似文献   

渭河咸阳城区段天然河滩与由河滩改造的湿地公园中6类野生动物分布对比     

王军利  田金晶  胡雪瑛  汤文华 《湿地科学》2020,18(1):28-31

为了对比渭河城区段天然河滩与由河滩改造的湿地公园中野生动物的分布情况,进而对河流天然河滩的园林化改造进行评估。2016年5月至2018年4月,采用样带法、典型样方法和坑穴诱捕法,调查了渭河咸阳城区段天然河滩和被改造为湿地公园的河滩中鸟类的巢和蛇类、蛙类、刺猬类、兔形类、鼠类的分布及其数量。研究结果表明,在天然河滩采样地中,诱捕到的5类野生动物和鸟巢的数量都显著大于其在湿地公园中的数量(p<0.05),且天然河滩被改造为湿地公园后,蛇类、刺猬类和兔形类野生动物几乎消失。可见,将天然河滩改造为湿地公园,实现了城市人居空间的延伸,增加了游憩功能,但是,因其改变了原天然河滩的地形、土壤和植物群落,使得湿地公园失去了原天然河滩的大部分生态功能,野生动物失去了它们赖以生存的独特环境,其分布种类和数量皆显著减少。  相似文献   

云南东部江川生物群中的香肠状疑难化石——Tawuia化石属性的新解释     

李玉兰  王浩  刘傲然  李明  梁永忠  周颖  唐烽  任留东 《地质论评》2022,68(5):1585-1603

云南东部伊迪卡拉（震旦）系顶部灯影组旧城段的江川生物群是华南又一大类丰富且多样化的宏体化石群,其以碳质压膜的方式保存。在该生物群中,我们发现大量香肠状碳质压膜的宏体化石,与成冰(南华）纪全球大冰期之前中、新元古代地层中广泛分布的Tawuia碳膜化石的大小、形态非常相似。其最大宽度达4. 5 mm,最大长度可达4 cm,长宽比均>2,膜面光滑,未见其他稳定纹饰,有的化石标本边缘碳质保存较多,可见深黑色边缘环带。但部分化石保存的形态与常见的直棒状I形、U形、C形Tawuia化石相比却较为特殊,呈现直角L形、8字形、宽U形、环状O形等多种保存形态,个别标本弯折部位可见明显的碳质增厚和横脊纹残留,边缘残存有大小不一的刺状突起构造。这类特异形态保存的似Tawuia化石显然不能解释为以往较为公认的浮游型叶状体藻类,而可能与冰期前的新元古代早期鲁西、淮南宏体化石群中的疑似蠕形动物亲缘的化石有传承关系。上述新发现的化石形态表明：似Tawuia的碳膜宏体化石可能是多源属性的早期多细胞生物。其中短带至长带状叶状体,可见短柄突起及疑似固着器构造的化石可确认为底栖宏体藻类;多数的叶状体推测为香肠状或长囊状,生活史中包含远洋浮游的类型,可能归属于原始不分枝的多核体藻类或早期分化出的中空囊状的多细胞藻类;本文展示的部分规则变形的似Tawuia化石,更可能是两侧对称动物亲缘的,生活于近海的底栖生物体发生主动扭曲后,被特异埋藏所呈现出的特殊保存形态,而随机浮游或表栖的多细胞藻类死亡沉积时不会形成类似形态的化石。  相似文献   

重庆老鼓楼衙署遗址四川短尾鼩(Anourosorex squamipes)研究报告     

武仙竹  袁东山  N.I.Drozdov 《第四纪研究》2015,35(1)

2012年中国十大考古发现项目、重庆市老鼓楼衙署遗址发掘中(遗址位于29°33 ′13″N,106°34 ′46″E),通过使用筛选法、水洗法提取小哺乳动物骨骼标本的考古实践,成功提取到四川短尾鼩(Anourosorex squamipes)、贵州菊头蝠(Rhinolophus rex)等小哺乳动物骨骼标本.在我国古代城市遗址考古中,第一次发现了四川短尾鼩骨骼.四川短尾鼩标本的发现和研究,确认该动物在宋代时期已进入西南地区城市环境中与人类伴栖,对研究该动物适应人类城市环境、分析古代城市生态特征等具有重要意义.四川短尾鼩生态特征的综合分析工作,揭示出重庆老鼓楼衙署遗址古气候环境湿热;衙署庭院里具备有较大水源,有高大的阔叶树木遮荫,庭院地表面松软潮湿;衙署居室内采光偏少(光线较暗),可能有多种昆虫及软体动物会常进入人类居室活动;有多种小哺乳动物(如短尾鼩)伴栖于人类居室内、外,等等.该项研究工作,还从小哺乳动物骨骼标本提取、骨骼观测与鉴定方法等方面,为以后在动物考古中开展小哺乳动物研究积累了重要资料.  相似文献   

Dynamics of soil fauna in Da Hinggan Mountains, Northeast China   总被引：1，自引：0，他引：1  

Xueping Zhang  Yuan Sun  Lirong Huang 《中国地理科学(英文版)》2009,19(2):151-157

The dynamics of soil animals was studied in seven representative forest communities in the north of the Da Hinggan Mountains, Northeast China. The results indicate that it was distinctive in the changes of the numbers of soil animals and groups and diversity in relationship with seasons for macrofauna and torso-micro fauna in the study area. The numbers of the observed soil animals in different months were: October>August>June. Group number was larger in August and October, but smaller in June. The change of diversity index in different months was: August>June>October. The biomass for macrofanna in different months was: October>June>August. The composition and number of each functional group was relatively stable. In the community of the predominant soil environment, the percentage of saprophagous animals was higher than carnivorous animals and herbivorous animals. The dynamics changes of saprophagous and carnivorous animals were distinctive, increasing from June to October, while the change of herbivorous animals was unremarkable.  相似文献   

ECOLOGICAL DISTRIBUTION OF SOIL ANIMALS IN BROAD-LEAVED PINE FORESTS IN SOUTHERN SLOPE OF XIAO HINGGAN MOUNTAINS   总被引：1，自引：1，他引：0  

HOU Wei ling ZHANG Hua 《中国地理科学(英文版)》2000,10(3):276-281

Broad leaved pine forests are the typical zonal vegetation and its central distribution zone is in the Changbai Mountains in northeast China. However, because of man's disturbance and destruction, primitive broad leaved pine forests exist now only in a few areas such as the Changbai Mountains of Jilin Province and Wuying, Liangshui Natural Reserves of Heilongjiang Province, and the forests in other places are substituted by natural secondary forests (WANG, 1994). Broad leaved pine …  相似文献   

两种海藻提取物抗水产动物病原菌活性的初步研究   总被引：2，自引：0，他引：2  

路远  闫茂仓  徐宏翔  南春容 《海洋科学》2010,34(10):28-32

研究了两种大型海藻——羊栖菜(Sargassum fusiforme)、条浒苔(Enteromorpha clathrata)提取物对11种水产动物病原菌的抑制活性。结果显示:羊栖菜乙醇粗提物乙酸乙酯相对溶藻弧菌(Vibrio algi-nolyticus)的抑制作用最明显,抑菌圈可达21.6 mm;薄层层析表明羊栖菜乙醇粗提取物乙酸乙酯相有6条层析带,其中Rf=0.54带对哈氏弧菌(Vibrio harveyi)的抑制作用最强,抑菌圈可达13.6 mm;条浒苔乙醚粗脂对11种水产动物病原菌均表现出了较强的抑制作用,其中对灿烂弧菌(Vibrio splendidus)的抑制作用最强,抑菌圈可达24.7 mm;进一步的实验显示,条浒苔乙醚粗脂3种洗脱组分抗菌性均比粗脂减弱了,而其95%乙醇洗脱组分对恶臭假单胞菌(Pseudomonas putida)的抑菌圈仍可达13.8 mm。说明利用羊栖菜、条浒苔为开发海洋药物资源提供了可能。  相似文献   

长江流域动物生态分区     

张建平  郑远昌 《山地学报》1990,(3)

长江流域生态环境复杂,动物资源丰富。根据长扛流域生态环境的区域分异及动物类群组合的不同,并按照分区原则,将该流域分为10个动物生态区,即:Ⅰ.长江源头高原动物生态区;Ⅱ.横断山地动物生态区;Ⅲ.秦巴山地动物生态区;Ⅳ.四川盆地动物生态区;Ⅴ.贵州高原动物生态区;Ⅵ.三峡、武陵山地动物生态区;Ⅶ.桐柏山、大别山动物生态区;Ⅷ.长江中下游平原动物生态区;Ⅸ.江南丘陵动物生态区;Ⅹ.南岭山地动物生态区。  相似文献