In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. Divergent boundaries within continents initially produce rifts which eventually become rift valleys. Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges. Divergent boundaries also form volcanic islands which occur when the plates move apart to produce gaps which molten lava rises to fill.
The nearest star is Polaris.
Answer:
Basaltic magma -- SiO2 45-55 wt%, high in Fe, Mg, Ca, low in K, Na
Andesitic magma -- SiO2 55-65 wt%, intermediate. in Fe, Mg, Ca, Na, K
Rhyolitic magma -- SiO2 65-75%, low in Fe, Mg, Ca, high in K, Na
Explanation:
Answer:
Option (B)
Explanation:
The front often refers to the transition zone between the air masses that are comprised of different densities. It extends both vertically as well as horizontally. The passing of a front over a particular area depicts the change in its weather pattern. These fronts are responsible for the various weather events that cause hurricanes, tornadoes, and heavy rainfall.
There are basically 4 types of fronts, namely-
(1) Cold front
(2) Warm front
(3) Stationary front
(4) Occluded front
These front types occur when the air mass of variable densities moves from one place to another.
Thus, the correct answer is option (B).
