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In this chapter, E-W-trending tectonic systems are introduced, including those in the Arctic region, China, the Northern Hemisphere and the Southern Hemisphere.

In this chapter, N-S-trending tectonic systems are introduced, including those in the Ural Mountains in Asia, the island of Sakhalin in Russia, the Andes Mountains in South America, East Africa, the oceans and China.

In this chapter, N-E-trending tectonic systems are introduced, including those in China, New Zealand in the Pacific, northwestern Europe, the eastern United States, eastern South America and eastern Africa.

In this chapter, N-N-E-trending tectonic systems are introduced, including those in China, New Zealand–Tonga, the Eastern United States and the east coast of South America.

In this chapter, N-W-trending tectonic systems are introduced, including those in China, central Asia, the North Caucasus, the Zagros of the middle East, the western coast of North America and the Gulf of Suez.

In this chapter, epsilon-shaped tectonic systems are introduced, including those in China, Eurasia, Irkutsk in southern Siberia of Russia, Teli in Turkey, Gadomein France, England, North America, Cincinnati in southern North America and Brazil in South America.

In this chapter, S-shaped or reverse S-shaped tectonic systems are introduced, including reverse S-shaped systems in Qinghai–Tibet–Burma, China, the western coast of North America and S-shaped systems in western South America and western Africa.

In this chapter, rotation-torsional tectonic systems are introduced, including the rotation-torsional systems in China, the northern Sakhalin geese-shaped systems in northeastern Russia, the broom-shaped systems in the western Indian Ocean and southwestern Pacific, the double-ring compound rotation-torsional systems in Antarctica and the concentric radial systems in the Arctic.

Let L_S denote the language of (right) S-acts over a monoid S and let Σ_S be a set of sentences in L_S which axiomatises S-acts. A general result of model theory says that Σ_S has a model companion, denoted by T_S, precisely when the class of existentially closed S-acts is axiomatisable and in this case, T_S axiomatises . It is known that T_S exists if and only if S is right coherent. Moreover, by a result of Ivanov, T_S has the model-theoretic property of being stable.

In the study of stable first order theories, superstable and totally transcendental theories are of particular interest. These concepts depend upon the notion of type: we describe types over T_S algebraically, thus reducing our examination of T_S to consideration of the lattice of right congruences of S. We indicate how to use our result to confirm that T_S is stable and to prove another result of Ivanov, namely that T_S is superstable if and only if S satisfies the maximal condition for right ideals. The situation for total transcendence is more complicated but again we can use our description of types to ascertain for which right coherent monoids S we have that T_S is totally transcendental and is such that the U-rank of any type coincides with its Morley rank.