Continued from the previous post regarding the unusual and specific wordage of events that accompanied the destruction outlined in 3 Nephi and Helaman 14, and the earthquakes and volcanoes behind the destruction. The first ten were covered in the previous posts. Here we pick up with #15 below:
15. The rocks were split in half and broken into pieces on the face of the whole earth (3 Nephi 8:18)
Broken rock on the surface
• Earth’s crust, the outermost shell of the planet that makes up just 1% of Earth’s mass, is composed of igneous, metamorphic, and sedimentary rocks. The most abundant rocks in the crust are igneous, which are formed by the cooling of magma. Earth’s crust and lithosphere are mostly made up of igneous rocks such as granite and basalt. Metamorphic rocks have undergone drastic changes due to heat and pressure. Slate and marble are familiar metamorphic rocks. Sedimentary rocks are formed by the accumulation of material at Earth’s surface, with sandstone and shale being sedimentary rocks.
Earth’s layers constantly interact with each other, and the crust and upper portion of the mantle are part of a single geologic unit called the lithosphere. In the three layers of the earth—crust, mantle, and core—the crust is made of solid rocks and minerals. Beneath the crust is the mantle, which is also mostly solid rocks and minerals (punctuated by malleable areas of semi-solid magma). At the center of the Earth is a hot, dense metal core. These layers constantly interact with each other, and the crust and upper portion of the mantle are part of a single geologic unit called the lithosphere. The lithosphere’s depth varies, and the Mohorovicic discontinuity (the Moho), which is the boundary between the mantle and crust.
The breakup of rocks from huge blocks of rock occurs when environmental, gravitational or tectonic stresses act to sever molecular bonds within the rock, causing cracks to form or grow. As cracks intersect, smaller pieces of rock are separated. The process happens over and over again, releasing bedrock from the crust of the Earth and downsizing blocks of rock and boulders
To know how this happened in the Land of Promise, the Disciple Nephi stated: “And behold, the rocks were rent in twain; they were broken up upon the face of the whole earth, insomuch that they were found in broken fragments and in seams and in cracks, upon all the face of the land.”
An explanation of the meaning of his words are: “And behold, the rocks were rent in twain [broken in two]; they were broken up upon the face of the whole earth [both in the Land of Promise and beyond, possibility the entire planet], insomuch that they were found in broken fragments [small pieces], and in seams [a layer in the ground of a mineral or metal] and in cracks [called a fracture, which is any separation in a geologic formation, such as a joint or a fault that divides the rock into two or more pieces], upon all the face of the land [the Land of Promise]” (3 Nephi 8:18).
Showing both a Reverse Fault and an Oblique-Slip Fault
Further, a fault is a fracture or zone of fractures between two very large blocks of rock. Faults allow the blocks to move relative to each other. This means that fractures in Earth's crust cause the rocks on either side of the crack to slide past each other, which is the cause of earthquakes.
Thus, earthquakes are associated with tectonic activity—the movement along faults of divided blocks of rock that result when an oceanic plate dives under a continental plate. The more fractures, the more faults, the more faults, the more earthquakes, the more earthquakes, the more volcanic eruptions.
Most tectonic activity takes place at the boundaries of these plates, where they may collide, tear apart, or slide against each other. The movement of tectonic plates, which are huge slabs of rock, is made possible by thermal energy (heat) from the mantle (the solid rock plates float on top of a hot and semi-plastic mantle) part of the lithosphere, which makes the rocks of the lithosphere more elastic.
The most well-known feature associated with Earth’s lithosphere is tectonic activity—where huge blocks are subducted oceanic or continental plate broken down into giant slabs of rock “floating” on top of a hot and semi-plastic mantle.
This tectonic activity is the interaction of the huge slabs of lithosphere called tectonic plates, and all of this tectonic activity effects the Earth’s lithosphere, which is where most of Earth’s dramatic geologic events take place including orogeny (mountain-building) and deep ocean trenches, as well as earthquakes and volcanoes.
The Earth's Crust is like the skin of an apple—very thin compared to the other three layers, and only about 3-5 miles thick under the oceans and about 25 miles thick under the continents
Such tectonic activity can shape the lithosphere itself—both oceanic and continental lithospheres are thinnest at rift valleys and ocean ridges, where tectonic plates are shifting apart from one another. These plates usually move along smoothly but sometimes they stick and build up pressure until the rock bends and snaps—causing earthquakes.
This rocky lithosphere includes part of the upper mantle and crust, and when these blocks of rock are disturbed, or “divided in twain” (two pieces) and “broken up” into smaller pieces, it changes the dynamics of the lithosphere—which alters the topography and affects the land above.
In fact, a tectonic lithospheric plate is a massive, irregularly shaped slab of solid rock, whose size can vary greatly, from a few hundred to thousands of miles across—the Pacific and Antarctic Plates are among the largest. This rocky lithosphere varies from a thinner, crust-deep boundary at ocean ridges to thick, 124-mile boundary beneath cratons, the oldest and most stable parts of continental lithosphere.
While South America has tectonic plate movement along its entire west coast where the huge solid rock of the Nazca plate meets that of the South American plate; Mesoamerica is involved with very small plates, in the Cocos plate and the Caribbean plate. Where these plates meet is where most earthquakes originate. It should be noted that there are no plates connecting other plates in the Heartland or the Great Lakes locations within a thousand miles or more—the reason why they do not have earthquakes or volcanoes.
At these convergent plate boundaries between continental and oceanic lithosphere, the dense oceanic lithosphere, including the crust, always subducts beneath the continental. In South America, for example, the oceanic Nazca plate subducts below the South American plate.
Sometimes forces act to pull sections of the Earth's crust apart. At other times they are forced together. All this movement can cause rocks that were once underground to be brought up to the Earth's surface. This process is called uplift, with the rock cycle beginning all over again.
(See the next post, “Were there Really Earthquakes? – Part X, for more on the unusual and specific wordage of events that accompanied the destruction, and the understanding that earthquakes and volcanoes resulting in the destruction outlined in 3 Nephi).
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