Palynology of Cretaceous amber deposits of the Oriente Basin-Ecuador and the Eastern Cordillera-Colombia

Abstract

Several Cretaceous amber-bearing localities were recently discovered, including the Oriente Basin of Ecuador (Hollín Formation), and the Eastern Cordillera of Colombia (Une Formation at La Popa mine). A palynological study of 48 samples was carried out to date them and assess their broad floristic content. We date the Hollín Formation as spanning the late Aptian to the early Albian based on the co-occurrence of Callialasporites trilobatus, Retitricolpites operculatus and Callialasporites dampieri, among others. The sandstone lens containing amber from Une Formation at La Popa mine were dated as latest Aptian to early Cenomanian based upon the co-occurrence of Callialasporites dampieri, Afropollis jardinus, Ischyosporites variegatus and Gnetaceaepollenites retangularis. The palynoflora is dominated by high spore diversity suggesting humid climate conditions in the northwestern margin of Gondwana.