Abstract This study aimed to test the use of inland sponge spicules as proxy data for a Holocene paleoenvironmental reconstruction of the Trairi River valley, in the state of Rio Grande do Norte, in Northeast of Brazil. Spicules were recovered from sediments from two core samples obtained in the Fumo and Urtiga lakes, for depths of 0.60 m and 0.96 m, respectively. The following analyses were carried out: phytolith morphotype classification, isotope data (δ13C, δ15N‰), radiocarbon dating (AMS), grain size analysis, morphoscopy of sediments, and percentage of soil organic matter. Environmental reconstruction indicated seasons with dry and rainy conditions 1940 years BP. Isotope data pointed to the presence of plants (C3 and C4) and algae. Phytolith classification indicated that Poaceae, Cyperaceae, Arecaceae and/or Bromeliaceae occurred in the location. Spicules from the inland sponges Heterorotula fistula; Ephydatia sp.; Dosilia pydanieli; Corvoheteromeyenia heterosclera; Tubella variabilis; Radiospongilla inesi; Anheteromeyenia sp. were found in the core samples. Reconstruction based on isotope, phytolith and sedimentology results were compared with the spicule data and only D. pydanieli and H. fistula confirmed the other proxy information.

中文翻译：

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作为古环境工具的海绵针提供的财富信息评估：来自东北部的两个湖泊的案例（巴西）

摘要 本研究旨在测试使用内陆海绵骨针作为巴西东北部北里奥格兰德州 Trairi 河流域全新世古环境重建的代理数据。从 Fumo 和 Urtiga 湖中获得的两个岩心样本的沉积物中回收针状体，深度分别为 0.60 m 和 0.96 m。进行了以下分析：植硅体形态分类、同位素数据（δ13C、δ15N‰）、放射性碳测年（AMS）、粒度分析、沉积物形态学和土壤有机质百分比。环境重建表明 1940 年 BP 有干燥和多雨的季节。同位素数据表明存在植物（C3 和 C4）和藻类。植硅体分类表明，禾本科、莎草科、槟榔科和/或凤梨科植物发生在该地点。来自内陆海绵 Heterorotula fistula 的骨针；Ephydatia sp.; Dosilia pydanieli; Corvoheteromeyenia 异巩膜；风铃草; 放射海绵；Anheteromeyenia sp。在岩心样品中发现。基于同位素、植硅体和沉积学结果的重建与骨针数据进行了比较，只有 D. pydanieli 和 H. fistula 确认了其他代理信息。