Plate Tectonics - a compelling or possibly flawed model?

From my perspective, outwith the earth sciences, it would appear that plate tectonics (PT) has become the almost universally accepted paradigm. It is seen to explain what it was in the past that shaped the earth’s crust and presently continues to drive the dynamic processes determining the relationships between the continental land masses and the oceans. To pick up virtually any textbook underpinning curricula in the earth sciences around the world there seems to be a consistent and it has to be said compelling model being promulgated (see for example: McLeish, 1992; Skinner and Porter, 1995; Spencer, 1977; Wicarder and Monroe, 1999). Even if there is still lack of clarity and agreement as to what is actually providing the driving force, there appears to be relatively few who question the basic validity of the PT model. At first sight the growing body of evidence does seem to be overwhelming in support of the PT model, as illustrated by for example the very easy to read and excellent summary of the evidence by Sullivan (1991).

The topological fits between the continental shelves on opposing sides of the various oceans, and particularly the Southern Atlantic, would seem to be too close for pure chance. That the sediments immediately above the first basalt layers get older as the distance from the mid-oceanic “spreading zone” increases, strongly supports the idea of new ocean crust being formed from an upwelling of magma into the fissures being created when the “plates” are torn apart. Evidence of matching bands of new crust either side of the “spreading zone”, located in time by changes in magnetic signatures that have been locked-in when the magma hardened, is by many considered the pivotal evidence that the “plates” are being pulled apart to allow the creation of new mid-ocean crust. The concentrations of seismic and volcanic activity around the spreading zones and their complementary “subduction zones”, where the newer ocean crust is thought to be pushed beneath the relatively older continental crust, is consistent with the fundamental ideas of PT. So too are the matches in certain floral and faunal fossil remains within the continental crusts on opposing sides of oceans believed to have once formed a larger continental land mass split asunder by the processes of PT. In some cases there are even matches in existing living species on continents too far apart to have allowed natural spreading. All of this and much other carefully gathered data, creates a model that is beguiling in its simplicity and convincing in its consistency. And yet there are increasingly recognised factors that do not seem to fit into this apparently self-consistent and compelling model.

In the following  posts some of the serious geological evidence that does not appear to fit in with the basic ideas of PT will be briefly summarised. This critique has relied heavily upon the excellent summaries of critics such as Pratt (2000) and Meyerhoff et al (1996). It has also been bolstered by the increasing body of evidence being presented by Choi, Dickins, Smoot et alia in the publication New Concepts in Global Tectonics (NCGT), an e-publication explicitly set-up to allow the airing of evidence that is contrary to the ideas of PT and which it seems has too often been suppressed by the dominant publications in the field.  Some of the alternative explanations that have been put forward for the source of energy required to drive the dynamic processes of the Earth’s crust will be briefly touched upon. However, the main purpose of this and the following posts is to put forward an alternative model for the processes that might have been and continue to be at work in shaping the Earth’s crust. It will be argued that this new model is not only able to account for most of the processes and observations currently cited as evidence in support of PT but is also seemingly able to overcome most of its identified serious deficiencies. In particular, this new model will be demonstrated to be consistent with the evidence that vertical crustal motions are and have been as critical as horizontal motions in shaping our planet. Furthermore, the horizontal movements required for this new explanation are considerably less than those needed for PT. At temporal and spatial scales many orders less it has already been suggested that similar dynamic processes continue to shape periglacial environments both on Earth and some of the other planets and their satellites within the solar system.