Chapter 6, Problem 1RQ

To determine

The formation of clastic sedimentary rock from its unweathered parent rock.

Answer to Problem 1RQ

The process of formation of clastic sedimentary rock from its unweathered parent rock occurs with the weathering and erosion of the parent rock followed by of these transportation and deposition of these sediments through natural agents and finally the lithification sediments forming a complete rock.

Explanation of Solution

The erosion, transportation and deposition and subsequent compaction of sediments by the natural agents such as wind, water etc form the sedimentary rocks mostly. Calstic sedimentary rocks are the ones in which the loose clasts(individual minerals or rock pieces) are grouped together and are compacted.

Clastic sedimentary rocks are formed from its unweathered parent rock through multiple steps of transformations.

• Weathering is a phenomenon in which the bedrock disintegrates into grains due to physical or chemical processes.
• Erosion of weathered particles takes place in where, the pieces of rock or surface debris is detached from the surface. This is acted upon by the natural agents such as air, water or ice.
• These natural geological agents transport the eroded particles acting as a medium of transport. The rate of transportation depends on many factors such as viscosity, velocity of the medium etc.
• The deposition of these sediments take place when the velocity of the transportation medium totally slow down.
• Liithification is a process of transformation of these loose sediments into a solid rock. At first compaction of sediments takes place followed by the cementation of these sediments by the cementing materials such as quartz or calcite mostly. These are formed by the precipitation of groundwater and fills the remain space between the sediments, binding them together.