Sample Paper on Sedimentary Rocks

  1. What is sediment? Be sure to describe it in terms of geology.

Sediment can be referred to as a solid material moved from one location and deposited elsewhere(Sklar, Leonard and Dietrich 1088). Sediments can comprise minerals and rocks. Sediments move through a process called erosion through ice or water. This process leads to the formation of sedimentary rocks through various deposition and cementation of materials within water bodies and the surface of the earth. Therefore, sedimentation is a collective process that makes organic and mineral particles settle in an area. Before deposition, sediments are formed through erosion and weathering from their original location and later deposited in another place by ice, water and wind which are denudation agents.

 

  1. What is chemical weathering?In your response, include the following terms: biochemical and precipitate.

Chemical Weathering is the breaking down of minerals, rocks, and soil using contact with the atmosphere of the earth and waters (Hartmann 243). This process occurs with no movement. Therefore, it does not take place through erosion which embraces movement of minerals and rocks through agents like ice, water, snow, wind and waves. The weathering process happens through chemical and physical weathering. Physical or mechanical weathering entails the breakdown of soils and rocks by direct contact conditions of the atmosphere like water, heat, pressure and ice. The other classification is chemical weathering which takes place via direct effects on biochemically generated chemicals leading to the breakdown of minerals, rocks, and soils(Hartmann 247). On the other hand, physical weathering occurs in very dry or very cold conditions leading to a chemical reaction that causes the formation of precipitates. However, the two process tends to occur simultaneously as they accelerate each other.

 

  1. What is mechanical weathering?In your response, include the following terms: detrital and clastic.

This is an activity that aids mechanical forces in breaking down big rocks to become small. Often, mechanical weathering changes the size of a rock but does not alter its composition(Hartmann 250). The process invariably occurs in nature but at a slower rate that humans cannot detect. For instance, we usually feel temperatures change during the day and night. However, we cannot see rocks contract and expand as temperatures fluctuate. This movement eventually weakens the rocks leading to fracture and breakdown. Detrital particles comprise lithic fragments or mineral grains. Detritus fragments are referred to as a clastic rocks.

 

  1. How do clastic sedimentary rocks form? In your response, include the following terms: lithification, deposition, erosion, and compaction.

The clastic sedimentary rock is created through weathering process which leads to the breakdown of rocks into sand, pebble, and clay particles when exposed to water, ice and wind a process referred to as erosion. At the initial stage of deposition, they are regarded unconsolidated thus not considered to be a rock. Then lithification takes place to convert the unconsolidated sediments into rocks called sedimentary rocks. The process of lithification involves cementation and compaction.

 

  1. Name 4 grain sizes. To get you started, the largest size has been provided.
    1. Boulder
    2. Cobble
    3. Pebble
    4. Granule
    5. Sand

 

  1. What are rock strata? What are some things that make strata unique?

It refers to layers of sedimentary rocks stacked up. Although some other types of rocks have layers in them, the term strata are specifically meant for sedimentary rocks(Feng, Xia-Ting, and An 655). This implies that they have unique fragments. Geologists using this term to refer to many layers of rocks that appear in a large area. The term strata resulted from the study of rocks called stratigraphy. Referring to the sedimentation and layering also known as stratification.

 

  1. Name 4 sedimentary structures (a structure formed during deposition).
    1. Cross-Bedding
    2. Ripples
    3. Graded- Bedding
    4. Stratification

 

  1. Site your sources:

Feng, Xia-Ting, and Honggang An. “Hybrid intelligent method optimization of a soft rock replacement scheme for a large cavern excavated in alternate hard and soft rock strata.” International journal of rock mechanics and mining sciences 41.4 (2004): 655-667.

Hartmann, Jens. “Bicarbonate-fluxes and CO 2-consumption by chemical weathering on the Japanese Archipelago—application of a multi-lithological model framework.” Chemical Geology 265.3 (2009): 237-271.

Sklar, Leonard S., and William E. Dietrich. “Sediment and rock strength controls on river incision into bedrock.” Geology 29.12 (2001): 1087-1090.

 

  1. Using Google Draw, or a similar drawing program, sketch an image of a clastic sedimentary rock consisting primarily of fine gravel. You may insert your drawing at the end of this document or attach it separately to the assignment dropbox.

 

Using Google Draw, or a similar drawing program, sketch an image of a sedimentary structure (see Question 7) that could be created by the wind.  You may insert your drawing at the end of this document or attach it separately to the assignment dropbox