12.07.2015 Views

Untitled

Untitled

Untitled

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

a focus on tropical tree pollen types. This inventory(1145 taxa) gives, for each pollen taxonwhose nomenclature is discussed, informationon the habit, habitat and phytogeographical distributionof the plants they come from. Specialattention has been paid to pollen types with similarmorphology, which include several plant speciesor genera, whose biological or environmentalparameters can differ considerably.2008040057哥 伦 比 亚 杜 伊 塔 马 内 安 第 斯 盆 地 Pantano deVargas 全 新 世 花 粉 记 录 所 反 映 的 植 被 变 化 和人 类 影 响 = A Holocene pollen record of vegetationchange and human impact from Pantanode Vargas, an intra-Andean basin of Duitama,Colombia. ( 英 文 ). Gómez A; Berrío J C;Hooghiemstra H; Becerra M; Marchant R. Reviewof Palaeobotany and Palynology, 2007,145(1-2): 143-157Holocene environments in the intra-Andeanbasin of Duitama (Eastern Cordillera of Colombia,2510 m altitude) are presented based on the620 cm long Vargas pollen and sediment record.Seven AMS radiocarbon dates show these lakeand swamp sediments represent the period from8800 to 2610 14 C yr BP. We identified sevendistinct periods of environmental conditions inthe basin.From ca. 8800 to 7700 14 C yr BP (9450–8300 cal yr BP) Alnus and Myrica swamp forestgrew on wet soils. On the surrounding slopesAndean forest was present with Hedyosmum,Melastomataceae and Quercus. Between 7700and 6090 14 C yr BP (8300–6750 cal yr BP) openwater with aquatics alternated with peat-formingPlantago meadows reflecting repeated lake levelschanges. From 6090 to 5220 14 C yr BP(6750–5680 cal yr BP) open water and grassyvegetation around the lake was replaced by Alnus-dominatedswamp forest, suggesting lowerlake levels and drier climatic conditions. Between5220 and 4500 14 C yr BP (5680–4810 calyr BP) an alternation between Alnus-dominatedswamp forest and open grassy vegetation continued,reflecting fluctuating water levels. Atthat time Hedyosmum, Miconia, Quercus, Solanaceae,Relbunium and Rubiaceae were commonelements in the Andean forest. From about4500 to 3680 14 C yr BP (4810–3800 cal yr BP)Alnus-dominated swamp forest alternated withMyrica shrub and much organic material accumulatedin the basin. Evidence of deforestation(reduction of Quercus in particular), lowering ofwater tables and increasing disturbance, probablyby erosion (presence of Amaranthaceae/Chenopodiaceae,Borreria and Dodonaea)point to the settlement of pre-Hispanic populations.Between 3680 and 2610 14 C yr BP (3800–2470 cal yr BP) there is clear evidence of cropcultivation (presence of Zea mays) and frequentfires (high amounts of charcoal in the sediments).Erosion all over the basin led to significantsediment supply and the lake gradually changedinto a swamp. By this time pre-Hispanic populationshad used nearly all alder wood in thecatchment area. The uppermost sediments areoxidised and the last 2610 radiocarbon years ofthe Holocene are not represented, possibly dueto agricultural activities.2008040058南 极 维 多 利 亚 地 南 部 Carapace Nunatak 早 侏罗 世 费 拉 群 的 孢 粉 = Early Jurassic miosporesfrom Ferrar Group of Carapace Nunatak, SouthVictoria Land, Antarctica. ( 英 文 ). Ribecai C.Review of Palaeobotany and Palynology, 2007,144(1-2): 3-12Along the Transantarctic Mountains, thesiliciclastic foreland basin deposits of the BeaconSupergroup and the effusive rocks of theFerrar Group overlay the pre-Devonian metamorphicbasement. The Ferrar Group at CarapaceNunatak is composed of fluvial volcanicsandstones of the Carapace Sandstone Formation,which is overlain by the volcanic flows andbreccias of the Kirkpatrick Basalt Formation.Fossiliferous horizons are present in both formations.Palynological analyses have been carriedout on fifteen samples collected in marly–siltyhorizons within the Carapace Sandstone andKirkpatrick Basalt formations. Samples from theCarapace Sandstone Formation contain a scarcebut quite well preserved palynoflora, which isorange to light brown in colour. The spore–pollen assemblages lack dominant species andare very similar in composition. The stratigraphicallysignificant taxa Corollina torosa andPodosporites variabilis are present. The twosamples from the Kirkpatrick Basalt Formationcontain a very rich microflora dominated byCorollina species (mainly C. torosa) and Exesipollenitestumulus. Some representatives of thegenus Callialasporites are also present. Comparisonswith previous Carapace Nunatak andAntarctic palynological studies are discussed.2008040059日 本 宫 古 群 和 手 取 群 的 早 白 垩 世 陆 地 孢 粉 组合 及 其 古 植 物 地 理 区 系 意 义 = Early Cretaceousterrestrial palynomorph assemblages fromthe Miyako and Tetori Groups, Japan, and theirimplication to paleophytogeographic provinces.( 英 文 ). Umetsu Keita; Sato Yoko. Review ofPalaeobotany and Palynology, 2007, 144(1-2):13-24Terrestrial palynomorph assemblages werefound from the Lower Cretaceous MiyakoGroup in the Tanohata area, northeast Japan, and19

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!