Problems with radiometric dating of rocks
It met with widespread rejection, largely because the mechanism he suggested was inadequate -- the continents supposedly plowed slowly through the denser oceanic crust under the influence of gravitational and rotational forces.Interest was revived in the early 1950s with the rise of the new science of paleomagnetism, which seemed to provide strong support for continental drift.C-14 is produced in the upper atmosphere when nitrogen-14 (N-14) is altered through the effects of cosmic radiation bombardment (a proton is displaced by a neutron effectively changing the nitrogen atom into a carbon isotope).The new isotope is called "radiocarbon" because it is radioactive, though it is not dangerous.With the development of the basic principles of faunal succession and correlation and the recognition of facies variability, it was a relatively short step before large areas of Europe began to be placed in the context of a global geologic succession.This was not, however, accomplished in a systematic manner.
A few years later, these and other concepts were synthesized into the model of plate tectonics, which was originally called "the new global tectonics." According to the orthodox model of plate tectonics, the earth's outer shell, or lithosphere, is divided into a number of large, rigid plates that move over a soft layer of the mantle known as the asthenosphere, and interact at their boundaries, where they converge, diverge, or slide past one another.
-- This paper looks at the challenges confronting plate tectonics -- the ruling paradigm in the earth sciences.