Evidence for Vigorous Cretaceous Mantle Dynamics from Large Igneous Provinces
Coffin, MF and Eldholm, O, Evidence for Vigorous Cretaceous Mantle Dynamics from Large Igneous Provinces, Ocean Drilling Program Greatest Hits, Joint Oceanographic Institutions, USA, 2, 1, p. 30. (1997) [Internal Newsletter]
Conditions on Earth today are dramatically different from thosethat existed during the Cretaceous Period, which ended 65million years ago. Widespread evidence indicates that duringthe Cretaceous, which preceded the Cenozoic Era we are nowin, climate was considerably warmer, sea level was significantlyhigher, episodes of oceanic anoxia were more frequent, andmass extinctions were more common. In addition, seafloorspreading rates were higher, and Earth’s magnetic field wasuncharacteristically steady in that it did not switch from normalto reversed polarity for ~35 million years. The ODP has madecritical contributions to this list of Cenozoic-Cretaceouscontrasts. For example, ODP results have demonstrated that theCretaceous was a time when huge volumes of magmaticmaterial flowed to Earth’s surface from the mantle, and not justfrom the typical seafloor spreading process. Instead, most ofthe magma was injected upwards through volcanic hotspots.These eruptions formed many features, including two giantoceanic plateaus and several large igneous provinces (LIPs).