LO1

1.1 A   Modes of  formation of rocks :-

Soil and rock are the two most common solid earth component that we witness everywhere. Rocks are made of one or two minerals and require a high amount of energy to break and turn into soil particles. It requires less energy to break the particles that are loosely packed.

Rock is the natural substance which is an aggregate of mineral or mineraloids which could be separated after using a high amount of energy.

Various Processes that Played a Role in Bringing Different Types of Rocks

• The crystallization process: -Beneath the surface of the earth in the high pressure and heat reside the rock-forming minerals in a form known as magma which reaches to the surface of the earth through the volcano eruption. After meeting the cold environment the magma starts solidifying into the igneous rock. As the magma cools down it leads toward the different form of rock crystals.
• Erosion and Sedimentation:-Weathering breaks down earth’s surface into smaller pieces which are called sediments. Factors like gravity, running water, and ice transport these sediments into different places through erosion. In the sedimentation process, the sediments are deposited or buried down in the earth which give birth to other rock type known as sedimentary rock. Due to the higher pressure many sediments gets buried and cemented which gives the rise to another class of rock. Majority of the rocks were originated from this one process.
• Water participations :-In this process, hot water collides with the sulfide minerals and create the rock form. The hot water breaks the anion of the sulfide mineral and turns it into the rock.
• Metamorphism process:-It is the process where the rock is exposed to the utmost heat and light. Due to this, the rock gets salted and ended up becoming the rock with different characteristics. One of the group of rocks that falls under this category is the granite group of minerals.
• Solution Precipitates:- Sometimes, the calcite carbonates, oxides, and gypsum get dissolved into the water and could be solidified through the inorganic and biogenic activities.

1.1. B   Types of Rocks :-

1. Igneous rocks :-

Igneous rocks are formed by cooling down the magma that emerges from the volcano eruption. For scientists, it is a very important category of rocks as they can study them to study temperature, pressure, and composition that exist in the core of the earth. There are basically two types known as:

• Intrusive igneous rock: – This type of rock is formed when magma cools down and crystalized below earth’s surface. This slow cooling down process forms large size crystals. The intrusive igneous rock type includes pegmatite, granite, peridotite, diorite, and gabbro.
• Extrusive igneous rock: – This type of rock is formed when a volcano erupts on the surface of the earth and forms small crystal forms after cooling down. Magma that cools down fast after encountering the surface often form amorphous glass. The extrusive igneous rocks include basalt, obsidian, rhyolite, andesite, scoria, and tuff.

Use of Igneous Rocks in ancient and modern civilization

Igneous rocks come with lots of varieties and can be used in several places. The igneous rocks were also used by ancient Egyptians for statues and buildings. The researchers also found the vase made of diorite which leads to the conclusion that use of igneous rock was common in the ancient civilization.

In the modern civilization granite which is also an igneous rock type used in both construction and remodeling. It is considered as an ideal choice for the kitchen countertop. Apart from this peridotite is also used in jewelry.

Sedimentary Rocks:-

As mentioned earlier, this type of rock forms due to deposition and solidification of sediments. The Erosion and Sedimentation cycle moves continuously due to wind, air, glacier, river, and waves. There are two main ways by which sediment can be lithified:-

• Cementation: – In this process, layers of sediments are squeezed together by putting sediments on top of them for the excessive pressure. Through this process, non-organic sediments turn into the clastic rocks and if the sediments contain any organic material then, it turned out to be bioclastic rocks.
• Compaction: – In this, fluid is filled in the empty gaps that exist in the loose particles of sediments and later crystallized to create rocks.

Types of Sedimentary Rocks:-

• Clastic sedimentary rocks: – This type of rock is produced by weathering process which actually breaks down the rock into smaller particles such as sand, pebbles, and clays through exposure of wind, ice, and water. Clastic sedimentary rocks are only one member of the rock family that also contains the fossils as well the indicators of climate change such as ripple marks, raindrops, and the mud cracks. It is strongly believed by the scientists that it is one of the ancient types of rocks. Sedimentary rocks that are composed of large sediments known as conglomerate sedimentary rocks.

• Sedimentary rocks which are basically made of silt are called siltstone. Silt is actually a granular material which exists in rocks in between1/16 and 1/256 mm in diameter.
• Shale is a grained sedimentary rock that forms from the clay. The clay is sediment which comes in 1/256 mm in diameter.
• Mudstone is the equal mixture of both clay and silt.

Metamorphic rock

Metamorphic rock has been modified into the igneous or sedimentary rocks due to continuous exposure to extreme heat and pressure while buried down to the earth. The term metamorphic defines the formation Meta refers to the change and morphic means form. Hence, it is the rock that changes forms.

Types of Metamorphic Rock

There are two types of metamorphic rocks known as Regional metamorphism and Contact metamorphism rock.

• Regional Metamorphism: – This type of metamorphic rock appears when rocks are buried into earth’s crust. The heat and pressure that forced them to convert is caused by the convergence of plates thus, this type of rocks are common information of mountain range.

When extreme pressure and heat put on the conglomerate, their large fragment shrinks down and took over the oval shape. This new type of rock is called Meta conglomerate. Most common examples of the Meta conglomerate are schist, slates, schist, phyllite.

Contact Metamorphism: – This type of rocks is the result of the changes that took place when the molten rock comes into the contact of solid surrounding rocks. The heat that emerges from other rocks alters the rock but no melting was there in the entire process.

1.2   What are the common rock-forming minerals:-

 

Characteristics called luster. The luster can be divided, two classes:

1. Metallic luster
2. Non-metallic luster

 

The Sensitivity of Minerals to Weathering:-

Weathering is a chemical and mechanical process in which minerals of a rock react with the water, air, ice, and heat and breaks down into smaller pieces. There are several factors that affect the rate of weathering and exposure to the atmosphere is one of them. Rocks buried down the upper surface of the earth are naturally protected by the external environment in comparison to the rocks that can be found on the upper layer, exposed to the ever-changing environment and climate.

1.3   The common usage of rocks:-

Rocks can be used everywhere from the foundation of a strong building to a small carpenter shop, it is everywhere. There are several sleek and shiny countertop remodeling businesses that depend on the rocks. The common forms of rocks such as clay, sand, gravel is used for

constructing buildings, strong dams, roads and more. Slate which is a form of rock is used to build sheet and roof to construction purposes. Magnetite is a rock mineral rock and the main iron ore used for making steel, building ships, kitchen appliances, highways and more.

LO1.1 Classifications of aggregates on the basis of size:-

The aggregate exists in various sizes. The size distribution of aggregates is called grading. Following are the two main categories of aggregates:

1. Fine aggregates: –When aggregates are sieved through 4.75 mm sieves are fine aggregates. Example of fine aggregates is sand, clay, and silt.
2. Coarse aggregates: – When aggregates are sieved through 4.75 mm but are less in size are coarse aggregates.

The task for LO1.1 a) Give an overview of the characteristics of aggregates for both sub base and mixing base in concrete.

LO1.1 A) Major Characteristics of Aggregates

Aggregates are generally inexpensive and don’t enter into the chemical reactions with water. Therefore, it can be used as an inert filter for concrete and mortar. The shape and texture of the aggregates certainly affect the fresh concrete properties more than the hardened one. Hence, the concrete is more practical when used with the round and smooth aggregates. So, rather than going with the rough and angular one. Natural sand and gravels from the rivers work perfectly fine as an aggregate. The grading of aggregates according to the size is important as it determines the paste required for the concrete.

LO2

2.1. Soil description for in-situ and sample material:-

In-situ is the process of remedying of the polluted site through natural ways. The compaction of soil is done when it started losing its fertility.

• Soil Classification:-

The soil classification differs from one continent to another but they serve one single motive which is gaining information about the nature and behavior of soil.

Classification of soil on the basis of grain size

The soil can be classified as clay, gravel, sand, silts, and gravels on the basis of the size of the grain.

Textural classification.

When it comes to using the soil for the construction purposes the texture also matters. The texture indicates the physical properties of soil and how it will work. Soil with high sands are light whiles soil with high in clay is the heavy one.

• American association of state highway and transport officials (AASHTO) .

 

1. Description of basic soil properties:-

Soil contains minerals, organic matter, particles, water, and air. The combination of these determines the structure, porosity, texture, chemistry, and color. Basic properties of soil include:

Soil texture

The soil is made of different particles and minerals. The soil texture refers to the size of the particle it has made of. The texture determines whether the soil is free draining or not. The soil texture could be determined in percentage which depends on the weight of the particles like silt (0.002 to 0.05 mm), sand (particles between 0.05 to 2.0 mm), clay (<0.002 mm).

Soil structure

The soil structure can be defined by how different particles of soils are clumped together. The structure of the soil changes according to the time.

Soil porosity

It refers to the total number of pores in the soil. The more pores the greater the soil will be.

Soil chemistry

Soil also contains positive and negative energy depending on their type. For instance, potassium and ammonium carry negative charges while soil with organic matter contains positive energy.

2. The product calculation and graphs related to the soil:-

Learning soil texture with the help of graph:-

Which soil texture covers the largest area?

Ans. Clay

Does sand actually a composition of 100% sand, 0% clay and 0% silt?

The soil has the 100% silt and 100% sand.

1. Sand porosity

The soil porosity is the ratio of the volume of voids and sand. The amount of porosity of clay in the soil can be in-between 50% to 30%.