Numerical models of the ocean-climate system indicate that during the early Late Ordovician, water from the higher southern latitudes flowed north toward the equator. The cold-water masses welled up into and penetrated the epicontinental sea of Laurentia. The "cold-water conditions" existed despite high levels of pCO 2 (∼15× preindustrial atmospheric levels) and did not necessarily indicate the onset of glaciation during the early Late Ordovician; rather the cold-water conditions may indicate the onset of a cooling event that plunged the Ordovician Earth system toward icehouse conditions that would lead later to the end-Ordovician (Hirnantian) glaciation. Furthermore, the observed distribution of cold-water masses across the southeastern margin of Laurentia is consistent with the interpretation that a cold-water event caused a regional extinction in the Mohawkian of eastern Laurentia.
|Number of pages
|Special Paper of the Geological Society of America
|Published - Jan 1 2010
All Science Journal Classification (ASJC) codes