准噶尔盆地南缘呼2井晚白垩世、古新世轮藻植物群的发现及其意义  

DISCOVERY OF CRETACEOUS AND PALEOCENE CHAROPHYTE FLORAS FROM WELL HU-2 IN THE SOUTHERN EDGE OF JUNGGAR BASIN

作　　者：杨景林[1] 王启飞[1] 卢辉楠[1] 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008

出　　处：《微体古生物学报》2005年第3期251-268,共18页Acta Micropalaeontologica Sinica

摘　　要：准噶尔盆地南缘的露头剖面经过数十年的生物地层研究,一直未发现可靠的晚白垩世和古新世轮藻植物群。1995年,在准噶尔盆地南缘覆盖区的呼图壁背斜上钻探了呼2井,于井下3085—3588m井段发现了丰富的轮藻化石,其面貌迥异于地面所见的各轮藻组合。通过对该轮藻植物群的系统研究,发现其中含轮藻化石17属23种5比较种和3变种,包括1新种。根据各属种的时代分布,建立了两个组合:1.晚白垩世Charatenuis-Horni-charaprolixa-Mesocharacf.biacuta组合,大致相当于马斯特里赫特期;2.古新世Stephano characunei formis-Grovesichara kielani-Sphaerochara nana组合。本文的研究成果完善了准噶尔盆地南缘的轮藻组合序列,同时也揭示了准噶尔盆地南缘凹陷区从边部向中心,随沉积条件的变化,地层层序趋于完整。Though the biostratigraphical researches have been done for nearly seventy years, the Late Cretaceous and Paleocene charophyte floras had not been found in the southern edge of Junggar Basin until the Well HU-2 was drilled in 1995. From the depth of 3 085-3 588m in the Well HU-2 rich charophyte fossils were obtained and their features are different from other assemblages found at the outcrop sections. Within the charophyte floras, 17 genera, 23 species （including 1 new species）, 5 species conformis and 1 variety are identified. According to the geological range of these fossils, two assemblages are set up： 1.Chara tenuis-Hornichara prolixa-Mesochara cf. biacuta assemblage of Late Cretaceous age, assigned to Maastrichtian; 2. Stephanochara cuneiforrnis Grovesichara kielani-Sphaerochara nana assemblage of Paleocene age. The charophyte assemblage succession of the southern edge in Junggar Basin suggests that strata tend to be more complete from edge to centre in the southern edge depression area of Junggar Basin with the changes of sedimentary conditions.

关 键 词：轮藻 晚白垩世 古新世 呼2井 紫泥泉子组 准噶尔盆地 新疆 准噶尔盆地南缘 轮藻化石 植物群 

分 类 号：Q914[天文地球—古生物学与地层学]