Under which condition below would you expect a coarse grained extrusive rock like dacite to form? a. lava slowly flowing out of a fracture in the earth's surface b. 25km beneath earth's surface c. within a zone of fractured rocks below earth's surface d. quick cooling of lava occurring underwater

Option (A)

Explanation:

Dacite is an igneous rock that is light in color and is usually fine-grained in nature. These rocks contain porphyritic texture where the larger grains are surrounded by the smaller grains. They are mostly found to be present in the lava flows and domes, sills, and in case of some pyroclastic materials. These are commonly found on the continental crust just above the subduction zones.

They are also found as extrusive rocks when magma exerts the force upward and comes out to the earth's surface through the fractures, forming lava. And due to the fast rate of cooling, these Dacite rocks are coarse-grained in nature. They are mostly associated with volcanic activities.

Thus, the correct answer is option (A).

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true