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Geology is a multifaceted science that encompasses the study of the Earth’s materials, processes, and history. Here’s a more detailed exploration of various aspects of geology: 1. Branches and Specializations in Geology A. Mineralogy B. Petrology C. Paleontology D. Structural Geology E. Geophysics F. Geochemistry 2. Processes Studied in Geology A. Plate Tectonics B. Rock […]Table of Contents Toggle 1. Branches and Specializations in Geology
The provided document contains a series of questions and answers related to geology, petrology, mineralogy, and soil science. It covers topics such as types of rocks, geological processes, elements in the Earth’s crust, and notable geological landmarks. Other subjects include historical figures in geology, notable geological events, and specific gemstones and minerals. Additionally, there are questions about geographical features and plate tectonics.
Unveiling the Mysteries of Igneous Rocks Introduction: Igneous rocks, born from the fiery depths of the Earth, hold a unique place in the geological tapestry. Formed through the solidification of molten magma or lava, these rocks play a pivotal role in shaping our planet’s crust. Let’s delve into the fascinating world of igneous rocks, exploring […]
Metamorphic rocks are classified based on their texture, mineralogy, and composition. The facies classification of metamorphic rocks is based on the conditions of temperature and pressure under which the rock formed. The following are the facies classification of metamorphic rocks: Each of these facies reflects a specific range of conditions under which the metamorphic rocks […]
Sand dunes are dynamic landforms created by the wind-driven accumulation of sand. They are typically found in deserts, coastal areas, and even some inland regions. Sand dunes can take on various shapes and sizes, influenced by factors such as wind direction, sand supply, and vegetation. Types of Sand Dunes: Formation of Sand Dunes: Sand dunes […]Table of Contents Toggle Types of Sand Dunes:Formation ...
What the meaning of Bauxite ? Bauxite is the most important aluminum ore. This type of rock consists mainly of the minerals gypsite Al(OH)3, bohemite γ-AlO(OH), anddiaspore α-AlO(OH) in a mixture that usually includes iron oxide goethite,hematite,the clay mineral kaolin, and small amounts of titanium minerals such as anatite, TiO2,ilmenite, and FeTiO3. , and FeOTiO2. […]Table of Contents Toggle What the meaning of Bauxite ?
The mineralogical, chemical, and structural adjustment of solid rocks to physical and chemical conditions which have generally been imposed at depth below the surface zones of weathering and cementation, and which differ from the conditions under which the rocks in question originated. Metamorphism means to “change form,”. In other words, metamorphism is a process that […]Table of Contents Toggle Process of MetamorphismWhat are ...
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
✳️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 […]
Introduction Piping is a phenomenon in geotechnical engineering where subsurface erosion occurs, leading to the formation of channels or pipes within soil. This can result in significant structural failures, especially in embankments, dams, and levees. Understanding the causes, effects, and mitigation strategies for piping is crucial for ensuring the stability and safety of geotechnical structures. […]Table of Contents Toggle IntroductionCauses of Piping
Soil classification tests are methods of determining the physical and engineering properties of soils, such as moisture content, specific gravity, grain size distribution, Atterberg limits, and shear strength. These tests are important for geotechnical design and construction, as they help to identify the soil types, behavior, and reactivity on a site. Soil classification tests can […]
The Earth’s crust is divided into two major types: oceanic crust and continental crust. These two types of crust differ significantly in composition, structure, thickness, and other physical and chemical properties. Understanding the differences between oceanic and continental crust is fundamental to geology, as it helps explain various geological processes, such as plate tectonics, mountain […]Table of Contents Toggle 1. Composition2. Thickness
In geology, “trend” and “plunge” are terms used to describe the orientation of linear geological features, such as fold axes, mineral veins, or lineations. They are crucial for understanding the spatial orientation and behavior of these features in three-dimensional space.
Trend
Definition: The trend of a linear geological feature is the direction in which the feature extends horizontally across the Earth’s surface. It is measured as a compass bearing.
Measurement:Trend is expressed as a compass direction (e.g., N30°E), indicating the general direction of the feature when viewed from above.
Usage: Trend is used to describe the horizontal projection of linear features such as fold axes, fault lines, or mineral veins.
Example: If a fault line extends from the northwest to the southeast, its trend might be described as NW-SE.
Plunge
Definition: The plunge of a linear geological feature is the angle at which the feature inclines relative to the horizontal plane. It describes how steeply the feature dips into the ground.
Measurement: Plunge is measured as an angle from 0° (horizontal) to 90° (vertical) and is usually combined with the trend to fully describe the orientation of the feature. The trend gives the direction of the line in the horizontal plane, while the plunge gives the angle of inclination.
Usage:Plunge is used to describe the vertical angle of inclination of linear features like fold axes, lineations, or the intersection line of two planes.
Example: If a fold axis trends N30°E and plunges 45° to the northeast, the feature extends in a northeast direction and dips into the ground at an angle of 45°.
Combined Usage
To fully describe the orientation of a linear feature in three-dimensional space, both trend and plunge are used together. This provides a complete understanding of the direction and angle at which the feature is oriented.
Example:Consider a fold axis with a trend of N45°E and a plunge of 30°. This means the fold axis extends in a northeast direction (N45°E) and dips into the ground at an angle of 30° from the horizontal.
Summary
Trend: The horizontal direction or compass bearing of a linear geological feature as it extends across the Earth’s surface.
Plunge: The angle of inclination of a linear feature relative to the horizontal plane, indicating how steeply the feature dips into the ground.
These terms are essential for geologists when mapping and analyzing the geometry of geological structures, as they provide a precise description of the orientation and behavior of linear features in the subsurface.