| The Miocene Pisco Basin of Peru is known for abundant, well-preserved marine vertebrate fossils (Esperante et al. 2000). Cetacean fossils are particularly abundant---so much so that we were able to locate 10 outcrops containing specimens in cross section, which allowed us to do detailed sedimentological studies of the beds surrounding the whales. We discovered that six of the 10 specimens were buried in channels; the details of the other four burials are too disparate to meaningfully group together in categories.Chapters 3, 4, and 5 describe and discuss the six specimens found in channels, while Appendix A contains descriptions and discussions of the other four locations.;The dominant sedimentary structure associated with all of the whales is hummocky cross-stratification, which forms during waning storms and implies substantial sediment accumulation during the event, whether by sediment input from the coast or other source, or by resuspension and redeposition of sediment (Dumas and Arnott 2006). The whales are encased in siltstone, made up primarily of varying ratios of siliciclastic material, diatoms, and volcanic ash. All of the material was acted upon by storm processes, as evidenced by the sedimentary structures, and even the beds of pure ash are ripple laminated or hummocky.;Taphonomic work done on Pisco fossils shows that they were buried rapidly (Esperante et al. 1999, 2008; Brand et al. 2004). Severe storms, the depositional environments indicated by the data we acquired, provide a mechanism to explain rapid rates of deposition and substantiate the findings of the taphonomic studies. |
