Three major hypotheses have been proposed for the origin of the crustal dichotomy : endogenic ( by mantle processes ), single impact, or multiple impact.
12.
"' Umbriel "'is a endogenic processes, and the moon may have undergone an early endogenically driven resurfacing event that obliterated its older surface.
13.
One endogenic model proposes an early episode of plate tectonics producing a thinner crust in the north, similar to what is occurring at spreading plate boundaries on Earth.
14.
Hypotheses proposed to explain how the two primary tectonic events may have occurred are usually divided into endogenic and exogenic processes, both of which will be discussed in this article.
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Just ask how scarce the term is endogenic is not a term that even an informed amateur is going to immediately understand, and is particularly over-technical in a lead.
16.
Schultz suggested compositional differences or endogenic modification as possible causes of the color contrasts among the floor, wall, and rim areas of the dark-halo craters rays, although secondary craters are well preserved.
17.
The resurfacing may have been either endogenic in nature, involving the eruption of fluid material from the interior ( cryovolcanism ), or, alternatively it may be due to blanking by the impact ejecta from nearby large craters.
18.
A new theory based on the Southern Polar Giant Impact and validated by the discovery of twelve hemispherical alignments shows that exogenic theories appear to be stronger than endogenic theories and that Mars never had plate tectonics that could modify the dichotomy.
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However the smooth appearance of the plains together with their sharp boundaries ( impact shaking would have produced a wide transitional zone ) indicates that they formed by endogenic intrusion, possibly along the lines of weakness in the Tethyan lithosphere created by Odysseus impact.
20.
The geology of Pluto, for example, described by Ward and Brownlee as " without mountains or volcanoes . . . devoid of volcanic activity ", and mountain ranges like Norgay Montes and Hillary Montes comparable in relative size to those of Earth, and observations suggest the involvement of endogenic processes.
