Deformation of the Earth's Crust - cause and effect
Deformation of the Earth's Crust - cause and effect

Deformation of the Earth's Crust - cause and effect$39.60 AUD

A quantitative analysis of geological processes which have shaped the Earth.
Shear stresses will be experienced by any element of the Earth's crust subject to migration across the latitudes: compression under an equatorial to polar migration; tension in the opposite direction. This outcome applies whether one adheres to the mobile plate tectonics model or to the concept of (geographic) polar wander.
The stresses involved in a full equator to polar shift, or vice versa, are predicted to a first order of accuracy. These "maximum geoid stresses" are shown to be inadequate to produce failure - either compressive or tensile - in a thick continental (or shield) crust. While a pristine oceanic crust should be capable of withstanding the maximum compressive stresses, failure in tension is indicated to be possible at stresses well below the maximum level. For a simplistic bi-modal crust, failure of the oceanic crust is exacerbated at the interface with continental crust, producing elongate rifting and slip strike faulting. The subsided oceanic crust - a geosynclines - becomes the focus of sedimentation from the adjacent continental mass.
The strength of infilling sediments, if composed partly of argillaceous sediments, can be predicted. On this basis, it is demonstrated that the subsequent compressive stresses, as the equatorial conditions move away, soon become adequate to cause deformation, folding and thrust faulting of the full sediment pile - a fold mountain profile. The equatorial origin of a geosyncline/fold mountain sequence is confirmed from palaeo-climatic and palaeo-magnetic data for, among other examples, the Rocky Mountain Cordillera, the Appalachians, and the Mobile Belt of PNG.
The analytical (mechanics of materials) approach to geology reveals other surprising verdicts, for example:- the inappropriate interpretation of the stress conditions leading to slip-strike faults; the fallacy of a tensile origin for dykes, sills and basalt flows; while "sacred cows" such as isostasy, subduction and sea floor spreading are shown to be fallacious.
The book is divided into four themes.
THEME 1. Explanation of variable horizontal stresses in the Earth's crust and analyses of matters outlined above.
THEME 2. Earthquakes, artificially induced and natural seismicity. Shallow events are analysed as shear failures, typically on natural discontinuities, and this process appears likely to explain events as deep as the Benioff Zones. Very deep earthquakes (greater than 500 km) are suggested to take place by a form of hydraulic fracture and, incidentally, structure is indicated to be present in the Upper Mantle, at 600-700 km depth. On prediction: all natural materials give some warning of their intention to fail and this characteristic needs to be investigated in the case of earthquakes, if a better understanding of prediction is to be gained.
THEME 3. A close look at the assumptions on which the mobile plate tectonics model is based, using a mechanics of materials approach. Much of the present mobilist model is based on guesswork with the codicil that further research will prove the model to be right. Such an approach - relying on the results of future research - is not science, but faith. This theme also looks at the evidence in favour of geographic polar wander.
THEME 4. A global extinction mechanism by massive oceanic redistribution(s), under polar wander and/or transient increases in precession, is set out. Deep Sea Drilling findings and the characteristics of submarine canyons and abyssal fan deposits - in all oceans - confirm this proposal of massive sea level changes. Evidence from the Upper Pleistocene down to the Upper Bronze Age also reveals that extinction events did not cease with the demise of the dinosaurs (65 ma). Indeed, evidence for an asteroid prime mover in the case of the dinosaurs rests on some very shaky inferences.