Sediment deposition changed significantly at many outcrops and in many drill cores spanning this time interval. On land, modern mammal orders (including primates) suddenly appear in Europe and in North America. For example, in the marine realm, a mass extinction of benthic foraminifera, a global expansion of subtropical dinoflagellates, and an appearance of excursion, planktic foraminifera and calcareous nanofossils all occurred during the beginning stages of PETM. Fossil records for many organisms show major turnovers. Stratigraphic sections of rock from this period reveal numerous other changes. Paired δ 13C, δ 11B, and δ 18O data suggest that ~12 000 Gt of carbon (at least 44 000 Gt CO 2e) were released over 50,000 years, averaging 0.24 Gt per year. The period is marked by a prominent negative excursion in carbon stable isotope ( δ 13C) records from around the globe more specifically, there was a large decrease in 13C/ 12C ratio of marine and terrestrial carbonates and organic carbon. The onset of the Paleocene–Eocene thermal maximum has been linked to volcanism and uplift associated with the North Atlantic Igneous Province, causing extreme changes in Earth's carbon cycle and a significant temperature rise. The entire warm period lasted for about 200,000 years. The associated period of massive carbon release into the atmosphere has been estimated to have lasted from 20,000 to 50,000 years. The exact age and duration of the event is uncertain but it is estimated to have occurred around 55.5 million years ago. This climate event occurred at the time boundary of the Paleocene and Eocene geological epochs. The Paleocene–Eocene thermal maximum ( PETM), alternatively " Eocene thermal maximum 1" ( ETM1), and formerly known as the " Initial Eocene" or " Late Paleocene thermal maximum", was a time period with a more than 5–8 ☌ global average temperature rise across the event. Note that the excursion is understated in this graph due to the smoothing of data. The Paleocene-Eocene thermal maximum (PETM) is characterized by a brief but prominent excursion, attributed to rapid warming. Climate change during the last 65 million years as expressed by the oxygen isotope composition of benthic foraminifera.
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