volcano and pillow lava

Volcano:
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.The volcano has got lot of parts and each one has another function.

VOLCANO PARTS:

-Ash: Fragments of lava or rock smaller than 2mm in size that are blasted into    the air by volcanic explosions

-Lava flow: The far that the lava travels depends on the temperature of the flow

-          Lava dome:  Roughly circular month-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano.

-Lava: Molten rock that erupts from a volcano that solidifies as it cools

-Vent: Are the locations from which lava flows and pyroclastic material are erupted.

-Tephra: Fragments of rock that are produced when magma or rock is explosively ejected.

-Crater: Mouth of volcano – surround a volcanic vet

-Lahar: Is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water.

-Fissure: Is a linear volcanic vent trough with lava erupts, usually without any explosive activity.

-Dike: Magmatic dikes form when magma intrudes into a crack then crystallizes as a sheet intrusion, either cutting across layers of rock or through an unlayered mass of rock.

-Magma: Molten rock beneath Earth´s surface

-Magma chamber: A magma chamber is a large pool of liquid rock found beneath the surface of the Earth

WHAT IS A PILLOW LAVA?

Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava under water. Pillow lavas in volcanic rock are characterized by thick sequences of discontinuous pillow-shaped masses, commonly up to one metre in diameter.

FORMATION:

They are created when magma reaches the surface but, as there is a large difference in temperature between the lava and the water, the surface of the emergent tongue cools very quickly, forming a skin. The skin cools much faster than the inside of the pillow, so it is very fine-grained, with a glassy texture. The magma inside the pillow cools slowly, so is slightly coarser grained than the skin, but nevertheless it is still classified as fine grained.

As a whole, the Cantabrian Mountains are remarkable for their intricate ramifications, but almost everywhere, and especially in the east, it is possible to distinguish two principal ranges, from which the lesser ridges and mountain masses radiate. One range, or series of ranges, closely follows the outline of the coast; the other, which is loftier, forms the northern limit of the great tableland of Castile and León, and is sometimes regarded as a continuation of the Pyrenees. In some parts the coastal range rises sheer above the sea, and everywhere has so abrupt a declivity that the streams which flow seaward are all short and swift.