Tectonic plate boundaries

Figure 14.11 Map showing tectonic plates and their boundaries. The arrows indicate the direction of their movements (Courtesy World Book Encyclopaedia)...

To a first approximation, fast tectonic processes occur at plate boundaries (Fig. 9-6). The... 

Figure 1.1. Outline index map of the Japanese subduction zones. Thick lines with teeth are converging plate boundaries. Arrows indicate relative plate motions. Abbreviations su, Suruga trough sa, Sagami trough sf, South Fossa Magna triple junction och, Off Central Honshu triple junction ISTL, Itolgawa-Shizuoka Tectonic Line KSM, Kashima VLBl station (Uyeda, 1991).

Otsuki, K. (1990) Neogene tectonic stress fields of northeast Honshu Arc and implications for plate boundary conditions. Tectonophysics, 181, 151-164. 

The first indication of a possible connection between geological processes occurring at the boundaries between tectonic plates of the mid-oceanic ridges and the biogenesis problem was provided by J. B. Corliss (1981). He considered the hydrothermal conditions to be ideal reactors for abiotic synthesis these ideal conditions were the water temperature gradients, the pH, and the concentrations of solutes in the hot springs. The presence of certain minerals which could act as catalysts, such as montmorillonite, clay minerals, iron oxide, sulphides etc., was also very important. The initial model presented for the hydrothermal synthesis of biomolecules (Corliss, 1981) was modified, particularly by Russell (1989) and Wachtershauser (see Sect. 7.3). 

Continent-continent convergence A convergent boundary between two colliding continental tectonic plates. The Himalayas formed from the collision of the Indian continental plate with the Eurasian continental plate. Continent-continent convergence results in high mountains without substantial subduction and volcanism. 

Continent-ocean convergence A convergent boundary where an oceanic tectonic plate collides with and subducts underneath a continental tectonic plate. The volcanoes of the Andes Mountains result from the Nazca oceanic plate subducting under the continental South American plate. 

Convergent plate boundary Areas where tectonic plates collide. These boundaries include continent-continent, continent-ocean, and ocean-ocean boundaries. 

Divergent plate boundary Areas where adjacent tectonic plates are separating. A spreading zone. Dolomite A calcium-magnesium carbonate mineral, CaMg(C03)2-Dolostone A sedimentary carbonate rock primarily consisting of dolomite. 

Spreading zone A divergent boundary between two tectonic plates where magma from the asthenosphere rises and creates new crust on the adjacent plates. The Mid-Atlantic Ridge is an example of a spreading zone. 

Thickening at the plate boundary is predicted to occur until gravitational forces balance tectonic stresses and elevation reaches an equilibrium. This balance of tectonic and gravitational forces causes the deformation to propagate away from the plate boundary and for a plateau to grow outward in a smooth fashion (England and Houseman 1988). However, if the entire lithosphere was shortened and thickened by a factor of 2, an appropriate number for the doublethickness crust of the Tibetan Plateau, then the surface of the plateau is predicted to rise no... 

Island arc— A volcanic mountain range, like the Aleutians, built on a tectonically active plate boundary in the sea, which appears as islands. 

Ave Lallemant, H. G. 1977. Transpression, displacement partitioning and exhumation in the eastern Caribbean/South American plate boundary zone. Tectonics, 16, 272-289. 

The geology of Italy is ranked among the most complex and least understood in all of Europe. This is attributed to its location at the margin of several plate boundaries and tectonic regimes. This study focuses on the Southern Apennines... 

These tectonic plates have roughly definable boundaries that have been subdivided into three fairly arbitrary categories in the following manner 9 major (or primary) plates (area greater than 10 million km2), 8 minor (or secondary) plates (area less than 10 million km2 but greater than 1 million km ), and several tens microplates (or tertiary plates) (area less than 1 million km2 they are often grouped with an adjacent major plate). The major plates include Pacific Plate (103,300,000 km ). North American Plate (75,900,000 km ), Eurasian Plate (67,800,000 km ), African Plate (61,300,000 km ), Antarctic Plate (60,900,000 km ), Australian Plate (47,000,000 km ). South American Plate (43,600,000 km ), Somali Plate (16,700,000 km ), Nazca Plate (15,600,000 km ), and Indian Plate (11,900,000 km ).The minor plates include Philippine Sea Plate (5,500,000 km ), Arabian Plate (5,000,000 km ), Caribbean Plate (3,300,000 km ). Cocos Plate (2,900,000 km ), Caroline Plate (1,700,000 km ), Scotia Plate (1,600,000 km ), Burma Plate (1,100,000 km ), and New Hebrides Plate (1,100,000 km ). 

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