Cerro Ballena (meaning "Whale Hill") is a fossiliferous locality of the Bahía Inglesa Formation, located in the Atacama Desert along the Pan-American Highway a few kilometers north of the port of Caldera, Chile.
The unusual concentration of cetacean remains and other marine vertebrates is explained to have occurred due to poisoning by toxins secreted by algae (events also known as harmful algal bloom).
While this project considered archeological, faunal, floral, and landscape implications, paleontological research was not included, and thus, the prospecting and preservation of potential fossil findings was not given attention.
Although the fossil remains were secured by laws and ready to get unearthed, the unprecedented high concentration of nearly complete whale skeletons (over 30 individuals) difficulted the speed and efficiency of paleontological research, and by extent halted the progress on the subway expansion.
As such, Cerro Ballena began to become very noticeable in both national and global contexts, and numerous institutions from Chile joined efforts to drive progress at the locality excavation.
With authorization of the CMN, documentation and agreements with the Smithsonian Institution were conducted so skeletons could be prepared in their museums, further speeding up the research at Cerro Ballena.
[1][2] As a fruitful result of the extensive excavation works and in-field studies by researchers over the years, collected geological and paleontological data from the site was finally published in 2014, in a publication led by North American paleontologist Nicholas D. Pyenson and colleagues from Chie.
[3] Sediments and fossils of Cerro Ballena were deposited in a marine supratidal flat (flattened berm/shore or beach) during rise in sea-levels caused by transgressive–regressive cycling and tectonic subsidence along this part of the coastline.
It is unlikely that the deposition rate of this locality was regressively eroded or interrupted given the rise in sea-level suggested by the stratigraphy and age correlation with transgressive south beds.
As reflected by four fossil-bearing levels at Cerro Ballena, these HABs and mass-mortality events repeated at least in four rapid instances, thus preserving an exceptional concentration of marine vertebrate fossils.
[2] Because of the relative articulation and completeness of cetacean skeletons compared to other vertebrates, it is clear that scavengers were unable to fully target floating whale carcasses.