Question

Arrange the following in the correct sequence. i. Top soil with humus and vegetation
ii. Parent rock
iii. Weathered rock material
iv. Sub soil with sand, silt and clay
Options
A. i iv, iii, ii
B. ii, iii, i, iv
C. iii, iv, i, ii
D. I, iii, iv, ii

Answer 1

Answer:

Top soil with humus and vegetation-The uppermost horizon is called the topsoil layer. The topsoil layer is a mixture of sand, silt, clay and broken down organic matter, called humus. Humus is rich, highly decomposed organic matter mostly made from dead plants, crunched-up leaves, dead insects and twigs.

Parent rock, also referred to as substratum, refers to the original rock from which something else was formed. It is mainly used in the context of soil formation where the parent rock normally has a large influence on the nature of the resulting soil. ... Parent rocks can be sedimentary, igneous or metamorphic.

A single type of weathered rock often produces infertile soil, while weathered materials from a collection of rocks is richer in mineral diversity and contributes to more fertile soil. Soils types associated with a mixture of weathered rock include glacial till, loess, and alluvial sediments.

Subsoil is the layer of soil under the topsoil on the surface of the ground. Like topsoil, it is composed of a variable mixture of small particles such as sand, silt and clay, but with a much lower percentage of organic matter and humus,and it has a small amount of rocks which are smaller in size mixed with it.

Explanation:

In the earth sciences, parent rock, also sometimes substratum, is the original rock from which younger rock or soil is formed.

Weathering is the breaking down of rocks, soils, and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms.

Subsoil is the layer of soil under the topsoil on the surface of the ground. Like topsoil, it is composed of a variable mixture of small particles such as sand, silt and clay, but with a much lower ...

Answer 2

The correct sequence is - A. i iv, iii, ii

i. Top soil with humus and vegetation

iv. Sub soil with sand, silt and clay

iii. Weathered rock material

ii. Parent rock

i. Top soil with humus and vegetation:

• The topsoil layer is the highest horizon.
• The topsoil layer is made up of a combination of sand, silt, clay, and humus, or decomposed organic material.
• Rich, deeply decomposed organic mass known as humus is primarily consisting of dead plants, crumpled leaves, dead insects, and twigs.

iv. Sub soil with sand, silt and clay:

• The layer of soil beneath the topsoil on the ground's surface is known as the subsoil.
• Similar to topsoil, it is made up of a fluctuating mixture of small particles including sand, silt, and clay, but it contains significantly less humus and organic matter.
• It also contains a minor number of smaller pebbles.

iii. Weathered rock material:

• While weathered materials from a variety of rocks are richer in mineral diversity and contribute to more fertile soil, a single type of weathered rock frequently results in unproductive soil.
• Glacial till, loess, and alluvial deposits are three soil forms connected to a mixture of worn rock.

ii. Parent rock:

• Parent rock may be metamorphic, igneous, or sedimentary.
• The parent rock (or protolith) in the context of metamorphic rocks refers to the original rock before metamorphism took place.

#SPJ3