The fact that volcanic rock has often been found early in the rock record but less frequently in later rock layers suggest to scientists the following conclusion about early earth: <span>volcanic activity was more common in the past than it is today. </span>Besides volcanic activity in general, also huge volcanic eruptions<span> were much </span>more common than today<span>.</span>
As the agriculture's are used to villages life and have to take care of the larger tracks of the lands and they thus live close by as compared to the semi-permanent horticulturalists.
As horticulture is not a permanent type of occupation and they don't need to bee close to the farms and required less maintenance.
