Sign up to join our community!
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
✳️Cinnabar is a toxic mercury sulfide mineral with a chemical composition of HgS. 🔷It is the only important ore of mercury. It has a bright red color that has caused people to use it as a pigment, and carve it into jewelry and ornaments for thousands of years in many parts of the world. Its […]
🔷Kimberlites, named after the town of Kimberly, South Africa, where they were first described, are volcanic rocks that originate in Earth’s mantle.🔷They are mined exclusively for diamonds. The photo shows the “Big Hole” at Kimberly.🔷The Hole was mined from 1871 to 1914 and reached a depth of 240 m below the surface. Subsequently it filled […]
Geological Time Scale The geological time scale is a system of chronological measurement that relates geological events and geological time to a numerical scale. It is used to describe the timing and relationships between events that have occurred throughout Earth’s history. The time scale is divided into four main parts: Eons, Eras, Periods, and Epochs. […] Table of Contents Toggle Geological Time Scale
What are Rare Earths? The Japanese call them “the seeds of technology.” The US Department of Energy calls them “technology metals.” They make possible the high tech world we live in today – everything from the miniaturization of electronics, to the enabling of green energy and medical technologies, to supporting a myriad of essential telecommunications and defense systems. […] Table of Contents Toggle What are Rare Earths?Which Elements ...
Geology 101 is the study of the Earth and its materials, structures, processes, and history. It is a broad field that encompasses many different disciplines, including mineralogy, petrology, paleontology, and geophysics. Geologists study the Earth’s physical features, including its rocks, minerals, soils, and water. They also study the Earth’s internal structure and the processes that […] Table of Contents Toggle Why Study Geology?What Do GEOSCIENTISTS ...
What is Volcano I heard about the volcano before 🤔??….We all see volcanoes in movies and news, but did you ask yourself why or how do they happen? On our trip today, we will explore the volcano and see its formation, why it happens, and how.. Are you ready, hero ??Let’s start our journey The […] Table of Contents Toggle What is VolcanoOne ...
An unconformity is a surface of erosion or non-deposition that separates two rock units that have different ages. It represents a time gap in the geologic record, and it occurs when sedimentary rocks are tilted, uplifted, and eroded before new sediment is deposited on top of them. There are three types of unconformities: Disconformities A […] Table of Contents Toggle There are three types of unconformities:
Minerals are homogeneous, naturally occurring, inorganic solids that have a definite crystalline structure and chemical composition. In 1995, the World Minerals Organization put another definition saying that “a mineral is an element or a chemical compound that is naturally crystalline and formed as a result of geological processes.”Minerals have their own specific physical properties which […] Table of Contents Toggle Minerals are classified according to their chemical composition.
The difference between mineral, metal and ores Many people confuse three completely different classes of substances (minerals, ores, and metals), so that metal becomes a mineral, and all minerals become ores. Minerals Minerals are inorganic solids (elements or compounds) that have distinct physical properties. Each substance has a known atomic structure and a fixed chemical […] Table of Contents Toggle MineralsOres materialsMetals
Geology online Quizzes questions and answers. Free online quiz with multiple-choice questions (MCQ) without registration. Geology Multiple Choice Questions geology questions and answers | geology questions for competitive exams | geology exam questions. Geology quiz questions and answers.geology quizes. Geology online quiz.
In geology, an angular unconformity is a specific type of unconformity that represents a gap in the geological record between two sets of rock layers where the lower set of rock layers is tilted or folded, and the overlying set of rock layers is relatively horizontal. Angular unconformities are signRead more
In geology, an angular unconformity is a specific type of unconformity that represents a gap in the geological record between two sets of rock layers where the lower set of rock layers is tilted or folded, and the overlying set of rock layers is relatively horizontal. Angular unconformities are significant because they indicate a period of deformation, erosion, and non-deposition in the Earth’s geological history.
Key points about angular unconformities in geology:
1. **Formation:** Angular unconformities form when an older set of sedimentary rock layers undergoes deformation, such as tilting or folding, due to tectonic forces or other geological processes. Subsequently, these tilted or folded layers are exposed to erosion, resulting in the removal of some rock material.
2. **Erosion and Non-Deposition:** After the deformation and erosion, there is a period of non-deposition, during which sedimentary rock layers are not being deposited in the area. This non-deposition is often accompanied by erosion, which can remove significant portions of the previously deposited rock layers.
3. **Overlying Horizontal Layers:** Over time, the tectonic activity or other geological processes responsible for deformation cease, and new sedimentary rock layers are deposited horizontally on top of the eroded and tilted layers. These new layers are typically younger than the eroded layers.
4. **Angular Relationship:** The key characteristic of an angular unconformity is the angular relationship between the underlying tilted or folded rock layers and the overlying horizontal layers. This angular discordance represents a significant break in geological time.
5. **Geological Significance:** Angular unconformities are valuable indicators of geological history because they reveal episodes of mountain building, tectonic activity, or other events that caused deformation and erosion. They provide evidence of changes in geological conditions over time.
6. **Examples:** A classic example of an angular unconformity can be found in the Grand Canyon of the United States, where horizontally deposited sedimentary rock layers from the Paleozoic era overlie tilted and eroded layers from the Precambrian era. This angular unconformity represents a vast gap in geological time.
7. **Identification:** Geologists recognize angular unconformities through careful field observations, mapping, and the study of rock sequences. The contrast in orientation between rock layers is a key diagnostic feature.
Angular unconformities serve as important markers in the geological record, helping geologists reconstruct the Earth’s history, understand past geological processes, and analyze the effects of tectonics and erosion on the Earth’s surface.
See less