Tectonics

[[File:TectPlates.png|thumb|upright=2.5|An example of a tectonic plate map. Tectonic plates and their characteristics are responsible for the majority of geographic features in the worlds of Songs of the Eons.

The development of Songs of the Eons tectonics is complete, and thus is already a part of the game, but subject to revisions.

Topography and Geology in Songs of the Eons are generated using a sophisticated plate tectonics model, the variables of which can be manipulated by the player to generate realistic worlds to their liking. Some of the attributes of tectonic plates include their velocity, crust density, varying sizes and shapes, and a general direction. When combined together, they create a multitude of various features that we witness in the real world depending on the relative positions and characteristics of the plates.

Major Plate Characteristics

Velocity: Tectonic plates can move up to 1.25 cm's per year. When they collide with other plates, they create geographic features depending on the intensity and directness of the collision along with the density of the crust.

Crust Density: The density of the tectonic plate at a given location. Oceanic Crust tends to be composed of dense mafic material while Continental Crust tends to be composed of light, felsic material.

Plate Size: Plates come in 3 sizes. Super Plates, Major Plates, and Minor Plates. Larger plates have longer plate boundary features with "inactive" interiors. Smaller plates have shorter plate boundary features and most of the land and sea of smaller plates tends to be geologically active.

Direction: Plate direction directly determines what kind of features exist on a boundary. Plates that crash directly into one another cause convergent features, when they move away from one another they produce divergent features, and when their movement is parallel to one another, it produces a transform boundary (usually with few conspicuous features).

Plate Convergence Features

Land / Land Collision: When two portions of continental crust from two plates collide directly they produce large, rugged mountains on both sides of the plate boundary. A real world example of this orogeny type is the Himalayas.



Ocean / Ocean Collision: When two portions of ocean crust from two plates collide directly, the heavier plate subducts under the lighter plate. This produces a contiguous trench on the "heavier" side of the plate boundary and an arc of volcanic islands on the "lighter" side of the plate boundary. An example of this phenomenon is the fire islands along the Pacific Rim.



Land / Ocean: When the continental crust of one plate collides directly with the oceanic crust of another plate, the heavier ocean plate subducts under the lighter continental crust of the opposite plate. This results in mountain formation and active volcanoes on the crust side and a trench on the ocean side. A real world example of this phenomenon is the Andean Mountain range of South America.



Shallow Ocean / Shallow Ocean: When plates collide along large passive margins, new mountains form on either side of the plate boundary and usually contain significant amounts of ocean material as such material is backed up onto the land. A real world example of this phenomenon is the Alpine formation throughout the Mediterranean.



Plate Divergence Features

Land / Land Divergence: When two plates diverge in which both sides of the plate boundary are continental crust, "rifting" along the plate boundary occurs. Rifting produces mountains on either side of the boundary with a "gap" in between directly following the boundary itself. A real world example of rifting is the Great African Rift.



Ocean / Ocean Divergence: When two ocean segments of a plate diverge, it causes seafloor spreading and an oceanic "ridge." Real world examples of oceanic ridges include the Mid-Atlantic Ridge and the Chile Rise.



Transform Boundaries

Transform boundaries exist where two opposite plates "slide past" one another. The geologic features of transform boundaries are subtle, but transform boundaries can still result in significant earthquakes.

Old Mountains

Orogens that occurred in the past produce mountains which erode significantly with time. Old mountains can either be swallowed by new orogens or they can exist in geologically inactive areas. They tend to be shorter, less rugged, and can vary significantly in size.



Hotspots, aka Magma Plumes

Hot Spots are intensely hot regions of the mantle below tectonic plates. This additional heat can cause magma to puncture the crust and form volcanoes on the surface. Hot spots can vary significantly in intensity, which influences volcano size. As tectonic plates move along the surface of the planet, hotspots will puncture the crust in new areas, forming a line of volcanoes which gradually erode over time. Hot spots over ocean crust generate seamounts as well as islands like those of the Hawaii Archipelago. Hot spots over land typically create "volcanic fields" and--- powerful enough--- rifting.





Other Oceanography Features

Continental Shelves: Continental Shelves are technically sections of a plate which are continental crust but which have been submerged by ocean. The result is a lengthy stretch of ocean which is shallow and slopes at a very slow rate.



Continental Slopes: The boundary zone between continental crust and oceanic crust. When the continental shelf ends, it slopes quickly toward the Abyssal plains. Sometimes large segments of a continent can be submerged, resulting in large shallow seas like the North Sea.



Abyssal Plains: The regions of a plate which are composed of oceanic crust. These regions are very deep but are occasionally punctuated by sea mounts or volcanic islands that breach to the surface.



Active Margins: Active Margins are the leading edges of a continent wherein the plate is crashing into an ocean plate. As a result, there is very little continental shelf along the coast. In the case of a direct collision (as in Chile), the ocean along the coast abruptly slopes into a trench. In the case of a transform boundary (as in the case of California) the ocean along the coasts quickly slopes toward the abyssal plains.



Passive Margins: Passive Margins are geologically inactive, as they do not exist along plate boundaries. As a result, the continental shelf tends to be significantly broader along passive margins.



Coral Reef Banks and Limestone Islands: Coral reefs grow in tropical regions near the equator in relatively shallow water. Given that stony coral generates a calciferous skeleton while they grow, they leave behind their skeletons after death. Eons of coral growth results in an increase in elevation of the ocean floor in banks where reefs grow. When sea level drops, parts of these banks are exposed to the surface as islands.