What Causes Landslides?
There are two primary categories of causes of landslides: natural and human caused. Sometimes, landslides are caused, or made worse, by a combination of the two factors. Natural Occurrences This … Read More
Kinking and chevron folding
Kink bands are common in well-laminated and anisotropic rocks rich in phyllosilicate minerals, and some field occurrences are shown in Figure 1. Kink bandsare centimetre to decimeter wide zones or … Read More
Silicate Versus Nonsilicate Minerals
It is worth noting that only eight elements make up the vast majority of the rock-forming minerals and represent more than 98 percent (by weight) of the continental crust (Figure). … Read More
Minerals Streak
The color of a mineral in powdered form, called streak, is often useful in identification. A mineral’s streak is obtained by rubbing it across a streak plate (a piece of … Read More
Artesian Systems
In most wells, water cannot rise without the use of pumps. If water is first encountered at a depth of 30 meters (100 feet), it remains at that level, fluctuating … Read More
Factors Influencing the Storage and Movement of Groundwater
The nature of subsurface materials strongly influences the rate of groundwater movement and the amount of groundwater that can be stored. Two factors are especially important: porosity and permeability. Porosity … Read More
Convolution
Convolute lamination or convolute bedding is a special type of intraformational deformation layering or lamination, characterized by meandering and winding laminates within a layer in concordant sequence with roof and … Read More
Kola Superdeep Borehole
The Kola Superdeep Borehole (Russian: Кольская сверхглубокая скважина) is the result of a scientific drilling project of the Soviet Union in the Pechengsky District, on the Kola Peninsula. The project … Read More
What Causes Rock to Deform?
Every body of rock, no matter how strong, has a point at which it will deform by bending or breaking. Deformation (de = out, forma = form) is a general … Read More
What Is Metamorphism?
Unlike some igneous and sedimentary processes that occur in surface or near-surface environments, metamorphism most often occurs deep within Earth, beyond our direct observation. Notwithstanding this significant obstacle, geologists have … Read More