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雅鲁藏布江以南的藏南特提斯喜玛拉雅白垩系一直备受关注,但迄今仍缺乏有关白垩纪孢粉组合序列的系统报导。本文详细研究报导了岗巴察且拉这一代表性剖面的孢粉化石。根据重要孢粉类群的分布和发生情况,从下部的门卡敦组向上经岗巴东山组、察且拉组和岗巴村口组共计产出2个孢粉组合及3个亚组合,由下向上依次为Microcachryidites antarcticus-Crybelosporites带和Gabonisporis-Crybelosporites pannuceus带。前者还可进一步的细分为3个亚带,自下而上分别为:Cicatricosisporites-Crybelosporites stylosus亚带、Cyclosporites hughesii亚带和Crybelosporites striatus亚带。根据孢粉类群的分布和发育特征以及沟鞭藻等化石,Microcachryidites antarcticus-Crybelosporites带的时代被推定为早白垩世Berriasian期—Albian期,Gabonisporis-Crybelosporites pannuceus带时代则为Cenomanian期至Coniacian期甚至Santonian期。前者的3个亚带的时代则分别为Berriasian期—Barremian期(Cicatricosisporites-Crybelosporites stylosus亚带)、Aptian期(Cyclosporites hughesii亚带)和Albian期(Crybelosporites striatus亚带)。上述组合可以与印度南部Cauvery等盆地孢粉组合很好的对比,与同期的澳大利亚组合则在早期(Microcachryidites antarcticus-Crybelosporites带)相似、后期具有差异。
The Himalayan Cretaceous in the south of the Brahmaputra south of the Brahmaputra has drawn much attention, but so far there is still no systematic report on the sequence of Cretaceous sporopollen assemblages. In this paper, the detailed reports on the sporopollen fossils from Ghazaba and the representative section are reported. According to the distribution and occurrence of important spore-pollen groups, a total of 2 sporo-pollen assemblages and 3 sub-assemblages were observed in the Qiandangangbaodongshan Formation from the Qiandamigang Formation in the lower part and from the lower part Microcachryidites antarcticus-Crybelosporites bands and Gabonisporis-Crybelosporites pannuceus bands upwards. The former can be further subdivided into three sub-belts, bottom-up: Cicatricosisporites-Crybelosporites stylosus, Cyclosporites hughesii and Crybelosporites striatus. According to the distribution and developmental characteristics of sporopollen assemblages and fossils such as dinoflagellates, the age of the Microcachryidites antarcticus-Crybelosporites belt is presumed to be Early Cretaceous Berriasian-Albian and that of Gabonisporis-Crybelosporites pannuceus is Cenomanian to Coniacian or even to Santonian period. The former three subbands are Berriasian-Barremian (Cicatricosisporites-Crybelosporites stylosus), Aptian (Cyclosporites hughesii) and Albian (Crybelosporites striatus), respectively. The above assemblage is well comparable to the sporopollen assemblage of the Cauvery Basin in southern India, which is similar to the early Australian Microcachryidites antarcticus-Crybelosporites and differs late.