Twinning Definition
Twinning is the observed intergrowth of multiple crystals in a symmetrical fashion. This term applies to the examination of rock thin sections, in the field of optical mineralogy.
Twinning is the observed intergrowth of multiple crystals in a symmetrical fashion. This term applies to the examination of rock thin sections, in the field of optical mineralogy.

Facies Facies: In the field of geology, the term “facies” represents a mappable, areally restricted part of a rock body that has different fossils or lithology from other contiguous beds deposited at the same time.

Dilatancy “Dilatancy” is the increase in the bulk volume of a soil substance during deformation. Dilatancy is caused by the change from a close-pack structure to an open-pack structure.

Plutonic Rock (Igneous) Definition The term “Plutonic” in the field of geology refers to an igneous rock, wherein the magma had originally cooled, solidified, and crystalized underground. A plutonic rock is generally coarsely crystalline (phaneritic) and is formed during a massive geologic intrusion of magma. In fact, outcropping (or daylighting) plutonic rocks are geologic features…

Mesosphere Mesosphere: The mesosphere of a terrestrial planet is the third member of the atmosphere. On Earth, the mesosphere starts atop the stratosphere at approximately 50 kilometers above mean sea level and terminates roughly 85 kilometers above mean sea level. The mesosphere is where most meteors burn to determination. Like the stratosphere, the air in…

Silicates Definition In the fields of geology and mineralogy, the term “silicates” refers to compounds whose crystal structure contains SiO4 tetrahedra. Silicates are either isolated or joined to form groups, rings, single or double chains, sheets, or three-dimensional frameworks.

Effective Size (D10) “Effective Size” (D10) is an engineering geology term. Effective Size represents a diameter that directly corresponds to the percentage, by weight, of grains that equal to 10% on the grain-size diagram. To illustrate, 10% of the soil sample particles are finer-grained, and 90% of the sample particles are coarser than the “effective…