The Thermal Maximum Paleocene-Eocene (PETM), also called Initial
Eocene Thermal Maximum, or Upper Paleocene Thermal Maximum was
an abrupt climate change that marked the end of the Paleocene
and the beginning of the Eocene. This is one of the periods of
climatic change that was most significant in the Cenozoic, which
suddenly altered ocean circulation and atmospheric, causing the
extinction of many genera of benthic foraminifera and causing
major changes in the mammalian land that marked the emergence of
the lineages present. In just 20,000 years, the average
temperature of land is increased by 6 ° C, with a corresponding
rise in sea level and warming of the oceans. Despite the warming
could be triggered by many causes, it is believed that were the
strong main volcanic activity and the emission of methane gas
that was stored in clath-rates in ocean sediments, and that
could increase warming by releasing large amounts of atmospheric
carbon depleted in the isotope carbon-13 . In addition,
atmospheric concentrati