Question

Elaborate on the stages of the process of lithification associated with the formation of sedimentary rock. please extent it up to 200 words.
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Answer 1

The rock cycle is a basic concept in geology that describes transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous. Each rock type is altered when it is forced out of its equilibrium conditions. For example, an igneous rock such as basalt may break down and dissolve when exposed to the atmosphere, or melt as it is subducted under a continent. Due to the driving forces of the rock cycle, plate tectonics and the water cycle, rocks do not remain in equilibrium and change as they encounter new environments. The rock cycle explains how the three rock types are related to each other, and how processes change from one type to another over time. This cyclical aspect makes rock change a geologic cycle and, on planets containing life, a biogeochemical cycle.

Answer 2

Lithification is the process that turns loose, unconsolidated sediment into solid sedimentary rock. Learn about the three ways lithification is accomplished, including compaction, cementation and recrystallization, in this lesson.

Lithification

Sedimentary rocks are created when little pieces of sediment, such as pebbles, sand and clay, join together. Okay, that seems simple enough, but how do these little pieces of sediment stick to each other to form a solid rock?

If you think about it, you could go down to the beach and pick up a handful of sand and try to squeeze the sand grains together really hard, but once you open your hand, the sand will run through your fingers. You could try wetting the sand with water. This would hold the sand together for a short time, but once that water evaporated, the sand grains would once again separate.

So, there must be some trick to get sediments to combine and form solid rock. In this lesson, we will learn about something called lithification, which is the process by which sediments combine to form sedimentary rocks.

Three Ways Lithification Occurs

The term lithification is derived from the Greek language. And it might help you to remember the meaning of this term if you recall that the prefix 'lithos' is Greek for 'rock.' So, we are really looking at the making of rock when we study lithification. There are two main ways that lithification occurs: compaction and cementation. We will also touch on a third way that is important to some sediments, called recrystallization.

Compaction

Compaction is the consolidation of sediments due to the intense pressing weight of overlying deposits. Compaction happens when sediments get buried. This literally squishes the sediment grains together, compressing them into a mass. With sufficient pressure and the passage of time, the grains get rearranged and more organized, much like winning a game of Tetris where the majority of the falling tiles fit snuggly together. As the sediments consolidate, the original pore space that divided them is reduced and any water that was in those spaces is squeezed out.