<P> Plate tectonics ( from the Late Latin tectonicus , from the Greek : τεκτονικός `` pertaining to building '' ) is a scientific theory describing the large - scale motion of seven large plates and the movements of a larger number of smaller plates of the Earth 's lithosphere , since tectonic processes began on Earth between 3 and 3.5 billion years ago . The model builds on the concept of continental drift , an idea developed during the first decades of the 20th century . The geoscientific community accepted plate - tectonic theory after seafloor spreading was validated in the late 1950s and early 1960s . </P>
<P> Plate tectonics ( from the Late Latin tectonicus , from the Greek : τεκτονικός `` pertaining to building '' ) is a scientific theory describing the large - scale motion of seven large plates and the movements of a larger number of smaller plates of the Earth 's lithosphere , since tectonic processes began on Earth between 3 and 3.5 billion years ago . The model builds on the concept of continental drift , an idea developed during the first decades of the 20th century . The geoscientific community accepted plate - tectonic theory after seafloor spreading was validated in the late 1950s and early 1960s . </P>
the part of the earth on which the tectonic plates are able to move is the
the part of the earth on which the tectonic plates are able to move is the
lithosphere
lithosphere