新疆准噶尔盆地西北缘早侏罗世三工河组孢粉组合

本文报道了采自新疆准噶尔盆地西北缘红山咀区拐114井三工河组的孢粉化石,33属58种。通过对孢粉组合的系统分析研究,认为三工河组的地质时代应归为早侏罗世。

AN EARLY JURASSIC SPOROPOLLEN ASSEMBLAGE FROM THE NORTHWESTERN MARGIN OF THE JUNGGAR BASIN,XINJIANG

Abundant spores and pollen grains dealt with in the present study were discovered fromWell Guai--114 along the northwestern margin of the Junggar Basin in Xinjiang,including 33genera and 58 species. In this assemblage gymnospermous pollen grains are dominant,amounting to 80. 9% ofthe total, mainly including Cycadopites (14. 5%), Protoconiferus (5. 8 %), Protopinus vastus(2. 5 %), Pityosporites (14. 5 %), Alisporites australis (1. 7 %), Protopicea (7. 9 %), Quadrae-culina (1. 6 %), Platysaccus (4. 9 %), Podocarpidites (5. 3 %), Psophosphaera (1. 2 %), andGranasporites (5%). Chasmatosporites and Ephedripties are rare; fern spores amount to 19.1%, mainly including Lycopodiumsporites (5. 8%) and Osmundacidites (2. 8 %), among whichLycopodiumsporites subrotundus amounts to 5. 4%, with small amounts of Concavisporites,Dictyophyllidites, Asseretospora and Apiculatisporis. These spores and pollen grains are commonly seen in the Early--Middle Jurassic strata,in association with small amounts of Chasmatosporites and Alisporites australis. Therefore,thesporopollen assemblage of the Sangonghe Formation under study may be assigned to EarlyJurassic in age.