on April 15, 2022
What are joints and bedding planes?
Regional SpecificsJoints are usually vertical. Joints are considered to be lines of weakness at right angle to the bedding planes. If you take a look at picture 1, you can see a number of joints. 2. Bedding planes are the horizontal junction between the layers of rocks. What is a bedding plane? Definition of bedding plane
on April 15, 2022
What are the four categories of magma?
Regional SpecificsBecause many of the properties of a magma (such as its viscosity and temperature) are observed to correlate with silica content, silicate magmas are divided into four chemical types based on silica content: felsic, intermediate, mafic, and ultramafic. What are 3 types of magma and what is their viscosity? Three general types are recognized: Basaltic
on April 15, 2022
How do minerals form from hydrothermal solutions?
Regional SpecificsHydrothermal mineral deposits are accumulations of valuable minerals which formed from hot waters circulating in Earth’s crust through fractures. They eventually create metallic-rich fluids concentrated in a selected volume of rock, which become supersaturated and then precipitate ore minerals. How can hydrothermal solutions form new minerals? hydrothermal mineral deposit, any concentration of metallic minerals formed
on April 15, 2022
Are all mountains fold mountains?
Regional SpecificsFold mountains are the most common type of mountain. The world’s largest mountain ranges are fold mountains. These ranges were formed over millions of years. Fold mountains are formed when two plates collide head on, and their edges crumbled, much the same way as a piece of paper folds when pushed together. Which mountains are
on April 15, 2022
How did the Archean period end?
Regional SpecificsWhat happened at the end of the Archean eon? In the Archean Eon, oxygen-filled in the atmosphere, and most of the world’s iron ore was deposited. Because the Earth’s conditions stabilized, eukaryotic and multicellular life could finally emerge in the Proterozoic Eon. When did the Archean era began and end? Etymology and changes in classification
on April 15, 2022
What are flute marks?
Regional SpecificsWhat is the flute mark? Typically, flute marks are bilaterally symmetrical heel-shaped hollows eroded into mud beds by debris-laden currents, acting either on prior defects on or within the bed, or on self-created defects, if the mud is insufficiently strong. Mud ripples closely resemble two-dimensional forms of current ripple. How do Flute marks form? Flute