FIRST CETACEAN FOSSIL RECORDS FROM ECUADOR, COLLECTED FROM THE MIOCENE OF ESMERALDAS PROVINCE

Cetacean fossils from Ecuador are reported for the first time on the basis of fragmentary remains referred to odontocetes, collected during our investigations of Neogene stratigraphic sequences outcropping along the northern coast (Esmeraldas Province). One specimen was collected near Las Peñas village in the Lower-Middle Miocene sediments of the Viche Formation and consists of ear bones and mandibular fragments surely belonging to Ziphiidae. It represents the oldest record of this family in the southeastern Pacific and one of the few records of this family in South America. The other fossil was collected near Rio Verde village in the Upper Miocene sediments of the Angostura Formation and consists of an isolated tooth exhibiting some ziphiid affinities. Pd

Coarse grained deposits of Cerro Colorado, Isla Santa Cruz, Galápagos archipelago (Ecuador)

Coarse grained deposits of Cerro Colorado, Isla Santa Cruz, Galápagos archipelago (Ecuador). On the Island of Santa Cruz (Galápagos Archipelago, Ecuador), at Cerro Colorado, some lithostratigraphic members have been recognized on the basis of sedimentological and paleontological features, as well as of different depositional environments. The stratigraphic sequence from the oldest to youngest deposits are : 1. Reddish Sandstone member ; 2. White Biocalcarenite member ; 3. Sandstone and Conglomerate member of Cerro Colorado ; 4. White Sandstone member. Members 1 and 2 refer to a beach depositional environment, and particularly to shoreface and foreshore. The third member has been interpreted as fan-delta deposits ; these deposits are arranged in five fining-upward cycles controlled by volcanic-tectonic activity. The last member consists of sand wave deposits made up of reworked beach sediments.Dépôts à grains grossiers du Cerro Colorado, Isla Santa Cruz, Archipel des Galápagos (Équateur). Les données sédimentologiques, paléontologiques et de dépôts ont permis de caractériser une séquence lithostratigraphique qui affleure à Cerro Colorado (Ile Santa Cruz, Archipel des Galápagos, Équateur). Cette séquence est formée de diverses unités qui, de la plus ancienne à la plus récente, sont : 1. grès rougeâtres ; 2. calcaires bioclastiques blancs ; 3. grès et conglomérats de Cerro Colorado ; 4. grès blancs. Les unités 1 et 2 ont été rapportées à un milieu de dépôts de plage, en particulier de "shoreface" et de "foreshore", tandis que l'unité 3, interprétée comme un dépôt de "fan-delta", est constituée de 5 cycles de type "fining-upward" qui sont contrôlés par l'activité tectono-volcanique. La dernière unité représente les dépôts de "sand-wave" constitués de sédiments de plage remaniés.Depositos con granos burdos del Cerro Colorado, Isla Santa Cruz, Archipiélago de Galápagos (Ecuador). En este trabajo se ha caracterizado, en base a las evidencias sedimentarias, paleontoloógicas y de depósitos, una secuencia litoestratigráfica que aparece a Cerro Colorado (Isla Santa Cruz, Archipiélago de Galápagos, Ecuador). Constituyen esta secuencia diferentes unidades que, desde la unidad más antigua a las más reciente, resultan : 1. areniscas rojizas ; 2. areniscas calcareas blancas ; 3. areniscas y conglomerados de Cerro Colorado ; 4. areniscas blancas. Las unidades 1 y 2 se han referido a un ambiente de depósitos de playa, particularmente de "shoreface" y de "foreshore", mientras la unidad 3, interpretada como depósito de "fan-delta", es constituida de 5 ciclos de tipo "fining-upward" controlados por la actividad tectónica-volcánica. La última unidad representa depósitos de "sand-wave" constituidos de sedimentos de playa reelaborados.Bianucci Giovanni, Cantalamessa Gino, Landini Walter, Piccini Maurizio, Ragaini Luca, Valleri Gigliola, Varola Angelo. Coarse grained deposits of Cerro Colorado, Isla Santa Cruz, Galápagos archipelago (Ecuador). In: Documents des Laboratoires de Géologie, Lyon, n°125, 1993. Paléontologie et stratigraphie d’Amérique latine. Table ronde européenne. Lyon, 7-8-9 juillet 1992. pp. 59-71