Era beginning/end
After twelve hundred years of geological stablity and peace, the Second Great Turbulence began. There are more definite records of this one. Some oracles and druids and clerics spoke out in the years leading up to it. There may be some evidence of efforts that helped reduce the amount of turmoil. But there was still a ten year period of geological chaos, where tectonic plates shifted, volcanos erupted, and even rifts between plane developed. This was followed by the Second Calm.