Geography

Types and Characteristics of Metamorphic Rock

len Alfred Ajibola - 19th June, 2022 @ 04:01 PM

Topics in Geography

Environmental geography explained with its branches Igneous rock explained with its types and textures Characteristics of Igneous Rock What are Sedimentary Rocks? Formation and Types of Sedimentary Rock Characteristics of Sedimentary Rock Types and Characteristics of Metamorphic Rock Physical geography explained with its branches Geography Scheme of Work, SS1, First Term Geography Scheme of Work, SS1, Second Term Geography Scheme of Work, SS1, Third Term Classification and types of planets with their characteristics Planets of the solar system explained with their characteristics Functions of the Atmosphere Layers of the Atmosphere Solar System in Geography Composition of the Atmosphere Human geography explained with its branches What are metamorphic rocks? Formation of metamorphic rock?


Academic Questions in Geography

Please check out our Test Your Knowledge page to see all Questions and Answers

Earth's distance from the sun is approximately _____ million kilometers.

  • A. 147

  • B. 85

  • C. 40

  • D. 220

  • E. 309

  • F. 400

Which of the following is not a branch of physical geography?

  • A. Economic Geography

  • B. Religious Geography

  • C. Social Geography

  • D. Resource Geography

  • E. Settlement Geography

  • F. Industrial Geography

Water resource geography is a branch under physiography.

  • A. True

  • B. False

With regards to ozone, which of the following is incorrect?

  • A. Ozone is a triatomic molecule

  • B. Ozone layer aids in preventing excess ultraviolet radiation from reaching the earth

  • C. Ozone is a natural greenhouses gas

  • D. Ozone comprises of oxygen molecules only

  • E. Ozone layer brings about a global warming on earth

  • F. Ozone is present in the stratosphere

The atmosphere makes the followings possible on earth except _____.

  • A. Photosynthesis

  • B. Respiration

  • C. Rain

  • D. Ultraviolet rays

  • E. Global communication

  • F. Weather

The interface forming a boundary between the stratosphere and mesosphere is termed _____.

  • A. Mesoface

  • B. Mesopause

  • C. Mesostart

  • D. Stratoface

  • F. Stratopause

  • F. Stratostart

Which layer of atmosphere is closest to the earth?

  • A. Thermosphere

  • B. Mesosphere

  • C. Stratosphere

  • D. Ionosphere

  • E. Troposphere

  • F. Exosphere

Argon makes up _____ percent of the atmosphere.

  • A. 0.93

  • B. 0.002

  • C. 0.0005

  • D. 0.00009

  • E. 0.00005

  • F. 0.036

LEN ACADEMY SMART SCHOOL SOFTWARE

Image

Read more on its smart academic features here


Types of Metamorphic Rock:

Metamorphic rocks make up about 12% of the earth crust. Their formation requires the transformation of an existing rock or original rock called protolith. The protolith may be an igneous rock, a sedimentary rock or another older metamorphic rock.

Please read the introduction to metamorphic rock here.

We have two basic type of metamorphic rocks based on their appearances. They are:


  • Foliated metamorphic rocks: They have a layered or banded appearance. Foliation in metamorphic rocks imply that they have parallel arrangement of certain mineral grains which results into a striped appearance of the rock.

    Foliation results into a metamorphic rock when it is is put under pressure. This squeezes, flattens or elongates the minerals, thus making them align. This ultimately give the rock a layered, banded and platy (or sheet-like appearance), after the pressure application.

    Granite, gneiss and schist are examples of foliated metamorphic rock.

Please read igneous rock explained with its types and textures here.


The image below shows a foliated and non-foliated metamorphic rock:

Foliated and Non-Foliated Metamorphic Rock


  • Non-foliated metamorphic rocks: These metamorphic rocks are neither flat, layered, elongated nor banded in appearance. Also, they do not have a platy or sheet-like structure as seen foliated rocks.

    Regardless the amount pressure applied to the grains of non-foliated metamorphic rock, it will still not align. Marble, quartzite and limestones are examples of non-foliated metamorphic rock.

Please read on sedimentary rock explained with its formation here.

 

Characteristics of Metamorphic Rock

  1. Metamorphic rocks are crystalline in nature.

  2. Metamorphic rocks are always more dense and also less likely to be broken down by erosion when compared to igneous and sedimentary rocks.
    Please read the characteristics of sedimentary rocks here.

  3. Minerals are always present in metamorphic rocks. Some of these minerals include garnet, staurolite, kyanite, sillimanite and andalusite. Each mineral is only steady within certain limits which are dependent on the approximate temperature and pressures experienced by the rock during metamorphosis. In this regard, these minerals are termed ‘index minerals’.

  4. Some metamorphic rocks have foliated or banded texture while others do not (non-foliated).

  5. Metamorphic rocks are typically buried in the earth crust with its upper layers above it.
    You can read on physical and environmental geography here.

  6. Metamorphic rocks have a more coarse texture than their parent rock (protolith).

  7. Cataclastic metamorphism occurs alongside the tectonic plate faults where the rocks get rubbed with each other, leading to their reduction in grain size.

  8. Metamorphic rocks generally have higher density and lower porosity when compared to their parent rock.
    Please read on the characteristics of igneous rocks here.

  9. In low-grade metamorphic rocks, the protolith are condensed in a similar manner as in the composition of slate from shale.

  10. Metamorphic rocks are characterized with a variety of precious metals and stones.

  11. They make up about 12% of the earth crust.

Need more answers to this topic? Please enter your search below:

Kindly share this article via the links below:


len

Alfred Ajibola is a Medical Biochemist, a passionate Academician with over 10 years of experience, a Versatile Writer, a Web Developer, a Cisco Certified Network Associate and a Cisco CyberOps Associate.


Please click here to follow Len Academy on Google News.

Please like and follow our official facebook page here for great educational write-ups.

You can follow Len Academy on twitter here.Thank you.


Please Register here or Login here to contribute to this topic by commenting in the box below.


Amazing facts in Geography

Pumice - Len Academy

Pumice is a rock that floats on water

There are more stars in space than there are grains of sand on a beach

Africa on the globe hemispheres - Len Academy

Africa is the only continent with land in all four hemispheres of the globe

Venus is the only planet that spins in a clockwise direction

Black holes aren't black. They only give off a dark glow because they are constantly consuming matter

The world's quietest room is located at Microsoft's headquarters in Redmond, Washington. This Microsoft's laboratory room measures a background noise of -20.35dBA; and that's a deafening silence

The universe has a color named cosmic latte

An earthquake is more likely to happen in Japan than any other country

Only 2 countries have the color purple in their national flag. Both countries are:

Nicaragua and Dominica

With 221,800 islands, Sweden is believed to have more islands than any other country in the world.


NOTABLE POINTS IN Geography

The atmosphere consists of gases that surround the entire surface of the spherical shaped earth. The compositions of these gases are as follows:

Composition of the Atmosphere -Len Academy

  • Nitrogen (N2): 78.09%
  • Oxygen (O2): 20.95%
  • Argon (Ar): 0.93%
  • Carbon(IV)oxide (CO2): 0.036%
  • Neon (Ne): 0.002%
  • Krypto (Kr): 0.001%
  • Helium (He): 0.0005%
  • Xenon (Xe): 0.00009%
  • Hydrogen (H2): 0.00005%
  • Water Vapour: Variable

All of these gases (listed above) make up the atmosphere and are generally called air.

Please read more on the atmosphere and it's composition here

Human Geography focuses on the study of human beings, their origin, race, and how they are affected by the earth.

Human geography can be divided into the following branches:

  • Economic Geography: This aspect of human geography looks into the distribution of goods and services. Distribution of wealth across the globe is also considered here.

    Instances of economic geography include a study or research done on the richest nations on earth. During thus research, the processes accounting for their wealth are ascertained.


  • Religious Geography: It studies the origin and spread of religious groups including their beliefs.

    Instances of religious geography include the study of the Christian or Islamic religion as seen in documentaries.


  • Medical Geography: It studies the processes and events that bring about diseases and epidemics with regards to their geographical location, origin and distribution.

    As an instance, you may have heard about the geographical study and distribution of the disease 'COVID-19'. (Coronavirus is a case study here).

    Please read more on the branches of human geography here.

We have 3 main types or classes of rock based on how they are formed. These are:

1. Igneous Rock

Igneous Rock - Len Academy

 

2. Sedimentary Rock

Sedimentary Rock - Len Academy

 

3. Metamorphic Rock

Metamorphic Rock - Len Academy

Igneous rocks are formed when molten substances below the earth surface cools down and solidifies. These molten substances are called magma or lava. Magma can be derived from melting of existing rocks on the earth crust.

The solidification of molten magma into igneous rock may be below the earth's surface (intrusive) or on the earth's surface (extrusive), giving rise to the two types of igneous rock.

  • Intrusive Igneous Rock: These are igneous rocks that crystallizes below the earth’s surface. They generally cool slowly during the process of solidification and tend to produce large crystals.

    Intrusive Igneous Rocks are also referred to as plutonic igneous rocks. Examples are gabbro, granite and pegmatite.

  • Extrusive Igneous Rock: They are igneous rocks that form when molten magma erupts on top of the earth's surface. They cool down and solidify quickly, producing small crystals in the process. Sometimes, the molten magma cools so quickly, allowing no time for crystals to grow. This rapid cooling results in the formation of an amorphous glass.

    Extrusive Igneous Rocks are also referred to as volcanic igneous rocks. Examples are basalt, rhyolite and scoria.

Sedimentary rocks amount to about 76% of the earth's surface. They can be formed in different ways. These are:

  • By the deposition of the weathered remains of pre-existing rocks and their subsequent transportation and deposition. Sedimentary rocks formed in this way are known as clastic sedimentary rock.

  • By the accumulation and lithification of sediment or detrital rock.

  • By their precipitation from solution. Sedimentary rocks formed in this way are known as chemical sedimentary rock.

  • As a result of biogenic activities. Sedimentary rocks formed in this way are known as organic sedimentary rock.

Please read more on types of rocks here