Jurassic Floras of the Carapace Nunatak Area: Evolution and Paleoclimatic Significance

该奖项支持了一个项目，该项目系统地收集和分析了维多利亚地南部Carapace Nunatak的三个层次的侏罗纪化石区系，并完成了对赖特谷头附近的Shapeless Mountain类似年龄矿床的侦察。这些植物群代表了从南极洲大陆部分已知的最广泛的侏罗纪化石植物沉积物。从生物地层学和植物学的角度来看，它们都鲜为人知，因此，它们不仅对我们了解南极洲的植物变化很重要，而且对我们与冈瓦纳其他大陆的相关性也很重要。除了印痕和压缩外，该遗址还包含过矿化标本。在这种罕见的保存类型中，细胞和组织系统完好无损，因此可以评估这些侏罗纪植物的解剖和形态细节。甲壳中保存的过矿化花元素与近十年来研究的二叠纪和三叠纪相同。因此，从二叠纪一直到南极洲的上侏罗纪，结构上保存完好的植物化石连续体可供研究。在这种情况下，将有可能研究种子植物在古生代后期和延伸到侏罗纪的高古纬度的生长、发育和进化的细节。在卡纳帕斯努纳塔克早期的一次侦察中收集到的一些标本表明，这里有丰富的针叶树和种子蕨类植物。针叶树组分在评价主要针叶树科植物的基本性状状态方面具有重要意义，而种子蕨类在评价这些中生代裸子植物与地质上较年轻的开花植物的性状及其关系方面具有重要意义。该遗址还包含一些木质标本（小树枝，木头碎片），树木年轮将被分析，并与其他高纬度地区的年轮进行比较，包括较老的（二叠纪和三叠纪）和较年轻的（白垩纪，第三纪）。由于硅化的不均匀性和不连续的沉积层，现场工作预计主要包括乘坐直升机到现场进行一日游，然后在麦克默多站的克雷实验室对材料进行切片，以减少非生产性材料的收集。

OPP 9614847 Taylor and Taylor Abstract This award supports a project to systematically collect and analyze the Jurassic fossil floras from three levels at Carapace Nunatak, in southern Victoria Land, and to complete reconnaissance for similar aged deposits at Shapeless Mountain near the head of Wright Valley. These floras represent the most extensive deposits of Jurassic fossil plants that are known from the continental portion of Antarctica. They are poorly known, both from a biostratigraphic and floristic standpoint, and as such are important not only to our understanding of floral changes in Antarctica, but also to correlations with other Gondwana continents. In addition to impressions and compressions, the site also contains permineralized specimens. In this rare preservation type, cells and tissue systems are intact so that details about the anatomy and morphology of these Jurassic plants can be evaluated. The preservation of the permineralized floral elements at Carapace is identical to those of Permian and Triassic age that have been studied in over the past ten years. As a result a continuum of structurally preserved plant fossils extending from the Permian into the Upper Jurassic of Antarctica are available for examination. In this context it will be possible to examine details of seed plant growth, development and evolution at high paleolatitudes during the latter stages of the Paleozoic and extending into the Jurassic. The few specimens collected during an earlier reconnaissance at Carapace Nunatak suggest a flora rich in conifers and seed ferns. The conifer components will be important in evaluating basal character states within the major conifer families, while the seed ferns will be useful in evaluating the characters and relationships of these Mesozoic gymnosperms to the geologically younger flowering plants. The site also contains some woody specimens (small twigs, fragments of wood), in which the tree rings will be analyzed and com pared with those from other high latitude sites, both older (Permian and Triassic) and younger (Cretaceous, Tertiary). Because of the patchy nature of the silicification and the discontinuous sedimentary beds, field work is anticipated to involve primarily day trips via helicopter to the sites immediately followed by sectioning of material in the Crary Laboratory at McMurdo Station in order to reduce the collecting of unproductive material.