摘要:
提要：新疆准噶尔沙尔布尔提山及其附近地区是中国准噶尔—兴安地层区泥盆系及下石炭统发育的主要代表地区之一，历来受到地质学界的关注，研究工作也不断深入。本文主要涉及洪古勒楞组的下伏及上覆地层。将20世纪70年代区测队建立的洪古勒楞组及“和布克河组”底部的一套砾岩—砂岩—粉砂岩地层单独建立为哈尔段（新名）。哈尔段下部以大套砾岩为特征，可与下伏地层原朱鲁木特组的粉砂岩至砂岩地层明显区别。两者接触面起伏不平，可能代表了一定的沉积间断。哈尔段地层总体颜色为灰绿色、紫红色、深灰色等，仅产植物化石，未见海相化石，目前仅能依靠其中的斜方薄皮木确定其时代为晚泥盆世，与原朱鲁木特组时代一致，此外在岩相上也均属于陆相。本文将黑山头组下部称为那木段，以含铁锈色介壳层的深灰色致密钙质硅质粉砂岩以及暗色或灰色、灰绿色硅质泥岩、粉砂岩与(细)砂岩等为特征，与黑山头组中部（属石炭系）大套灰黑色的粉砂岩-泥岩的岩性有明显区别，也与下伏风化呈（褐）黄色的洪古勒楞组查斯段明显区别。该段含菊石Cymaclymenia spp.、Mimimitoceras sp.等以及三叶虫Omegops，表明其仍属于泥盆系；此外，该段新出现Syringothyris-Spirifer腕足类动物群，因而不同于查斯段的弓石燕类腕足动物群。
Abstract:
Abstract: The Xar Burd Mountain and adjacent areas of Junggar Basin in Xinjiang constitute one of the major representative districts for the study of the Devonian and Lower Carboniferous strata in the Junggar-Hinggan stratigraphic region, and hence have aroused much interest among geologists. In this paper, major strata concerned are those below and above the Upper Devonian Hongguleleng Formation. The Haer Member (new name) is named to represent the basal part of the original Hongguleleng or “Hebukehe” Formation established by the Regional Geological Survey in the 1970’s, which is characterized by a large suite of conglomerate-sandstone-siltstone. A thick interval of conglomerates features the lower part of the Haer Member, which is distinctly different from the underlying original Zhulumute Formation; the contact between the two units is undulatory, probably representing a minor hiatus. The member is variously colored, including grayish green, purple-red, dark gray, etc. It yields plant fossils only, with its age assignable to the Late Devonian based on the plant Leptophloeum rhombicum, which is consistent with the original Zhulumute Formation in age, and probably also in the common nature of terrestrial facies due to the absence of marine fossils. The lower part of the Heishantou Formation is named the Namu Member (new name), which is characterized by dark gray dense sandy limestone or calcareous/siliceous siltstone with some ferruginous shelly coquinas and dark or gray, grayish green siliceous mudstone, siltstone, and (fine) sandstones. The overlying Carboniferous middle part of the Heishantou Formation is distinguished from the Namu Member by its large suite of gray-black siltstone-mudstone. The underlying Chasi Member (Hongguleleng Formation) is distinct from the Namu Member in its weathering (brown) yellow color of the rock. The Namu Member yields the ammonoids Cymaclymenia spp. and Mimimitoceras sp. and the trilobite Omegops, which suggests that the member still belongs to the Devonian. In addition, the new brachiopod Syringothyris-Spirifer fauna is present in the Namu Member, which is different from the cyrtospiriferid fauna of the underlying Chasi Member.
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