Aperçu des sections
chapter 1
The rock cycle describes the continuous process of formation, alteration, and transformation of rocks on Earth's surface. It involves the interplay of igneous, sedimentary, and metamorphic rocks through various geological processes like weathering, erosion, deposition, heat, and pressure.
Sedimentary rocks are formed from deposits of pre-existing rocks or pieces of once-living organism that accumulate on the Earth's surface. If sediment is buried deeply, it becomes compacted and cemented, forming sedimentary rock.
chapter 2
Getting a sedimentary rock involves transforming sediment into rock through diagenesis processes. Diagenesis is all the physical and chemical changes a sediment undergoes after deposition in a sedimentary basin under relatively low pressure and temperature conditions that prevail at shallow depths. Diagenesis stops where metamorphism begins.
Chapter 3
Rocks are classified into different categories based on the origin of their elements or their composition.
Diagenesis transforms loose sediment into a consolidated rock; this is lithification. It's a relatively simple process: if water flowing through sediment, like sand for example, is oversaturated with certain minerals, it causes these minerals to precipitate in the pores of the sand, which then bind the sand particles together; resulting in a sedimentary rock known as sandstone. The degree of cementation can be low, creating a brittle rock, or it can be extensive, leading to a very solid rock.
Chapter 4
Introduction:
A sedimentary rock is a rock formed by the deposition of sediments. These sediments accumulate in a sedimentary basin (= accumulation site) in a marine or continental environment. This sedimentation takes place on the Earth's surface (a sedimentary rock is an exogenous rock). Sedimentary rocks result from the accumulation of sediments, usually deposited in layers or overlapping beds called strata. This is followed by diagenesis (= a set of physico-chemical processes) which leads to the hardening of the sediment and thus the formation of a rock. They result from the accumulation of various sediments, solid elements, and precipitation from solutions.