Dinoflagellate cysts assigned to the subfamily Protoperidinioideae are frequently recorded in Miocene coastal deposits, and their relative abundance is directly related to primary productivity and favorable post depositional conditions. However, these microfossils are poorly studied in Brazilian Miocene sequences. This paper presents the results of a palynological study on 18 samples obtained from the core CBM001-ST-RS drilled in the coastal plain of southernmost Brazil, related to the Cidreira Formation, Pelotas Basin. Forty-nine taxa are identified, 46 dinoflagellate cysts, two genera of chlorophyte algae, and one acritarch species. Overall, the samples are characterized by large numbers of Spiniferites spp. and Brigantedinium spp., as well as a significant richness of the subfamily Protoperidinioideae. Several species of dinoflagellate cysts indicate a Miocene age, but the record of Sumatradinium hamulatum and Quadrina? condita restricts the age of the interval analyzed to the middle Miocene. Both the PMI and the P/G palynological indices indicate a neritic marine environment and moderate primary productivity, respectively.

在中新世沿岸沉积物中经常记录到属于原虾科的亚鞭毛囊肿，它们的相对丰度与初级生产力和有利的沉积后条件直接相关。但是，这些微化石在巴西中新世序列中研究较少。本文介绍了对18个样品的孢粉学研究结果，这些样品取自巴西最南端沿海平原与佩洛塔斯盆地奇德雷拉组有关的CBM001-ST-RS岩心。鉴定出四十九个分类单元，46个鞭毛藻囊肿，两个属的绿藻藻类和一个顶针种类。总体而言，样品的特征在于大量的棘藻类。和Brigantediniumspp。，以及丰富的Protoperidinioideae科。几种鞭毛的囊肿表明中新世年龄，但是记载了ha金龟和Quadrina？condita将分析间隔的年龄限制在中新世中期。PMI和P / G孢粉学指数分别表示海洋环境恶劣和初级生产力中等。