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Questions and Answers
What processes contributed to the alteration of original rocks into metamorphic rocks in Ethiopia?
What processes contributed to the alteration of original rocks into metamorphic rocks in Ethiopia?
Which areas in Ethiopia predominantly expose Precambrian rocks?
Which areas in Ethiopia predominantly expose Precambrian rocks?
What was the dominant geological process during the Paleozoic Era?
What was the dominant geological process during the Paleozoic Era?
What geological feature was formed at the end of the Paleozoic Era due to denudation?
What geological feature was formed at the end of the Paleozoic Era due to denudation?
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During the Mesozoic Era, what type of geological activity predominated?
During the Mesozoic Era, what type of geological activity predominated?
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What was the primary impact of the sea during the late Triassic period in the Mesozoic Era?
What was the primary impact of the sea during the late Triassic period in the Mesozoic Era?
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Which rock types are predominantly found beneath the surface rocks in Ethiopia?
Which rock types are predominantly found beneath the surface rocks in Ethiopia?
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What geological event characterized the transition between the end of Precambrian and the Paleozoic Eras?
What geological event characterized the transition between the end of Precambrian and the Paleozoic Eras?
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Which geological feature was formed due to the uplifting of the Arabo-Ethiopian landmass?
Which geological feature was formed due to the uplifting of the Arabo-Ethiopian landmass?
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What type of geologic activity mainly characterizes the Cenozoic Era?
What type of geologic activity mainly characterizes the Cenozoic Era?
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During which epoch did the greatest uplift of the Arabo-Ethiopian landmass occur?
During which epoch did the greatest uplift of the Arabo-Ethiopian landmass occur?
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What is the thickness of the volcanic rocks formed on the Ethiopian plateau?
What is the thickness of the volcanic rocks formed on the Ethiopian plateau?
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What is the nature of the tectonic force responsible for the uplift of the Arabo-Ethiopian landmass?
What is the nature of the tectonic force responsible for the uplift of the Arabo-Ethiopian landmass?
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What is referred to as Trappean lava?
What is referred to as Trappean lava?
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Which of the following regions predominantly contains old marine sediments?
Which of the following regions predominantly contains old marine sediments?
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What significant geologic feature is associated with the outpouring of basalt during the Cenozoic Era?
What significant geologic feature is associated with the outpouring of basalt during the Cenozoic Era?
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What geological feature is primarily formed as a result of tensional forces in the Earth's crust?
What geological feature is primarily formed as a result of tensional forces in the Earth's crust?
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During which geological epochs did the major rifting of the African Rift System take place?
During which geological epochs did the major rifting of the African Rift System take place?
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The connection between the Red Sea and the Gulf of Aden was a result of which geological event?
The connection between the Red Sea and the Gulf of Aden was a result of which geological event?
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What is the predominant surface feature of the Ethiopian plateau where it is not dissected by erosion?
What is the predominant surface feature of the Ethiopian plateau where it is not dissected by erosion?
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What phenomenon resulted in the accumulation of thick saline materials in the Red Sea area?
What phenomenon resulted in the accumulation of thick saline materials in the Red Sea area?
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What is the approximate distance that the Great East African Rift extends?
What is the approximate distance that the Great East African Rift extends?
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What tectonic activity contributed to the formation of parallel fractures in the Earth's crust?
What tectonic activity contributed to the formation of parallel fractures in the Earth's crust?
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Which area represents the widest part of the Rift Valley?
Which area represents the widest part of the Rift Valley?
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What geological formations were primarily laid down during the Mesozoic Era in Ethiopia?
What geological formations were primarily laid down during the Mesozoic Era in Ethiopia?
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What are the primary materials deposited as the depth of the sea increased?
What are the primary materials deposited as the depth of the sea increased?
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How did the Adigrat sandstone and Hintalo limestone formations change from southeast to northwest in Ethiopia?
How did the Adigrat sandstone and Hintalo limestone formations change from southeast to northwest in Ethiopia?
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Which of the following processes contributed to the sedimentation during the regression of the sea?
Which of the following processes contributed to the sedimentation during the regression of the sea?
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Which geological layer is found above the Hintalo limestone?
Which geological layer is found above the Hintalo limestone?
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What percentage of the land mass of Ethiopia is covered by Mesozoic sedimentary rocks?
What percentage of the land mass of Ethiopia is covered by Mesozoic sedimentary rocks?
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What type of marine environment is associated with the deposition of lime during the Mesozoic Era?
What type of marine environment is associated with the deposition of lime during the Mesozoic Era?
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What geological factors caused variations in the age and thickness of the sandstone layers in Ethiopia?
What geological factors caused variations in the age and thickness of the sandstone layers in Ethiopia?
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Which mineral occurrence is found in the Western and South-western-greenstone belt?
Which mineral occurrence is found in the Western and South-western-greenstone belt?
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What is an example of a site in the Southern greenstone belt?
What is an example of a site in the Southern greenstone belt?
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Which of the following is NOT a mineral found in the Northern greenstone belt (Tigray)?
Which of the following is NOT a mineral found in the Northern greenstone belt (Tigray)?
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What type of raw material is Mesozoic limestone used for?
What type of raw material is Mesozoic limestone used for?
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Which of the following mineral occurrences is associated with the Southern greenstone belt?
Which of the following mineral occurrences is associated with the Southern greenstone belt?
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Which volcano is considered the most active in Ethiopia?
Which volcano is considered the most active in Ethiopia?
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What major climatic change occurred during the Quaternary period?
What major climatic change occurred during the Quaternary period?
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Which of the following describes lacustrine deposits?
Which of the following describes lacustrine deposits?
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Which type of deposits are formed on the banks of rivers and flood plains?
Which type of deposits are formed on the banks of rivers and flood plains?
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What event is associated with the 'Pluvial Rains' in Africa?
What event is associated with the 'Pluvial Rains' in Africa?
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Which areas in Ethiopia are primarily rich in Quaternary deposits?
Which areas in Ethiopia are primarily rich in Quaternary deposits?
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What geological features were formed due to the excessive surface flow from the Pluvial Rains?
What geological features were formed due to the excessive surface flow from the Pluvial Rains?
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During which geological era did the Quaternary period occur?
During which geological era did the Quaternary period occur?
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Study Notes
Introduction to Geology
- Geology studies Earth's evolution, materials, and processes acting on them.
- Key aspects involve understanding past events and features unseen on the surface.
- Geological knowledge relies on inferred conclusions from observable surface features and measured data.
- Methods such as geophysics, geochemistry, and geochronology are crucial.
Geological Processes
- Processes are grouped into internal (endogenic) and external (exogenic).
- Endogenic: Volcanic activity, tectonic processes (folding, faulting, orogenesis).
- Exogenic: Weathering, mass transfer, erosion, and deposition, modifying landforms.
- Earth's landmass results from the combined action of endogenic and exogenic processes.
Geological Time Scale
- Measures Earth's history using four main units: epochs, periods, eras, and eons.
- Epochs are the smallest, representing millions of years.
- Periods group multiple epochs, and eras group multiple periods.
- Eons are the largest units of geological time.
- Geological time categories aren't uniform in length.
- Time scale is largely based on life occurrences and evolution.
Age Dating Techniques
- Relative Dating uses fossil evidence and rock layering to determine comparative ages.
- Absolute Dating relies on radioactive decay rates in rocks to determine precise ages.
- Carbon-14 technique dates organic material.
- Potassium-Argon technique is used for dating rocks.
Precambrian Era
- This era comprises the majority of Earth's history (4.5 - 600 million years ago).
- Orogenesis is a key process that lead to mountain-building.
- Extensive denudation following orogenesis leads to near-level rock surfaces.
- Precambrian rocks in Ethiopia form the basement often covered by younger formations
Paleozoic Era
- Lasted about 375 million years from 600 million to 225 million years ago.
- Main process was denudation, with vast mountain ranges reduced to flat surfaces.
- Limited deposition in Ethiopia resulting in rare Paleozoic rocks
Mesozoic Era
- Lasted from 225 to 70 million years ago.
- Alternating periods of land sinking and rising (epeirogenesis) affected the entire Horn of Africa.
- Subsidence resulted in sea incursions and deposition of sedimentary rocks.
- Sedimentary rocks of sand and lime were formed in Ethiopia, primarily in Tigray and other regions.
Cenozoic Era
- The most recent era, covering 70 million years to the present.
- Notable uplift of the Arabo-Ethiopian landmass, related to tectonic processes.
- Formation of the Rift Valley associated with tectonic and volcanic activity.
- Intense volcanism and faulting created significant structural features.
- Recent volcanic eruptions and sedimentary deposition within the rift valley.
Quaternary Period
- Marked by climatic fluctuations(ice ages and wet periods).
- Extensive erosion and river activity led to the transport and deposition of sediments in lakes.
- Lacustrine deposits (lake deposits), fluvial deposits (river deposits) and aeolian deposits (wind deposits) are common
- Recent volcanic occurrences associated with the rift valley formation are seen
Ethiopian Mineral Resources
- Mineral occurrences are linked to Precambrian rocks.
- Gold, platinum, tantalum, and gemstones are important resources, often found in certain geologic formations.
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Description
Explore the fundamentals of geology, including Earth's evolution, materials, and the internal and external processes shaping the planet. Dive into the geological time scale and learn how different events in Earth's history are categorized. This quiz will test your understanding of key geological concepts and methods used in the field.
