贵州独山下泥盆统丹林组陆相地层中的U形潜穴  

An Ichnofossil, U-Shaped Burrow, in Continental Deposit from the Lower Devonian Danlin Formation in Dushan County, Guizhou Province, China

作　　者：王约 

机构地区：[1]中国地质大学地球科学与资源学院

出　　处：《地质学报》2005年第1期1-6,i001-i002,共8页Acta Geologica Sinica

基　　金：现代地层学和古生物学国家重点实验室基金 (编号 0 2 3 116);贵州大学校立基金资助项目的成果

摘　　要：具蹼状构造的垂直 U形潜穴 Diplocraterion广泛产出于全球寒武纪—古近纪的滨浅海相中 ,被认为是 Seilacher(196 4 ,196 7)的 Skolithos遗迹相的主要分子 ,也见于中—新生代的河湖相中 ,被视为高能环境的重要分子。Diplocraterion在古生代陆相地层中的发现仍是首次。产于贵州独山丹林组陆相地层具有水平层理的黑色泥岩中的 Diplocraterion dushanensis ichnosp.nov.其近于平行的 U形栖管由许多的节管组成 ,节管和蹼状构造可能系造迹生物的居住潜穴阶段性地随沉积物的增厚而向上移动的过程中所形成 ,其造迹生物主要生活于泛滥平原相对平静贫氧的水体环境中。Diplocraterion Torell 1870, U-shaped with spreiten, was considered to be one of the main ichnofossils of Skolithos ichnofacies of Seilacher (1964, 1967) and widely found in shore and shallow-sea deposits from Cambrian to Paleogene as well as non-marine sediments from Mesozoic to Cenozoic in the world. It was regarded as one important indicator of high-energy environment. This is the first report of this genus from Paleozoic terrestrial strata. The Diplocraterion dushanensis ichnosp. nov. specimens found in black mudstone and silty mudstone with horizontal bedding from the Lower Devonian Danlin Formation in Dushan, Guizhou, are composed with spreiten and U-shaped burrow that consists of many nodositial tubes. The nodositial tubes and spreiten may be formed when the trace-maker, perhaps worm, burrowed upward. The author considers that the trace-makers dwelling in those burrows of Diplocraterion dushanensis ichnosp. nov. might live in a floodplain environment with calm water and poor oxygen. Ichnogenus Diplocraterion Torell, 1870.Diplocaterion dushanensis ichnosp. nov.(Pl. Ⅰ-5～8; Pl. Ⅱ-1～7, text figure 2).Material: twenty-three specimens, five field photographs. Description: U-shaped with spreite. The legs in the U as cords consist of many nodositial tubes that are commonly oblique to bedding, smooth on its surface, and have concave surfaces on their copulaes. The legs are mostly parallel to each other and vertical to the bedding. On the bedding plane, it is like a dumbbell. Burrow fill is structureless, and different in color from host rock. The color near the edges of the burrow and spreites are lighter than that of the host rock.Dimensions: The traces are 12 to 65 mm long, and the most length of U-shaped burrows is 65 cm. The diameter of the tubes varies from 0.3 to 0.5 cm, the distance between tubes is 0.2 cm to 1.2 cm. The length of nodositial tubes varies from 0.2 to 0.5 cm. Discussion: Diplocraterion dushanensis ichnosp. nov. differs from other ichnospecies of Diplocraterion in that the diameter an

关 键 词：陆相地层 泛滥平原 浅海相 古近纪 中-新生代 古生代 山丹 贵州独山 下泥盆统 寒武纪 

分 类 号：P534.44[天文地球—古生物学与地层学]