<h2>Phenocrysts and Porphyritic texture
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Explanation:
- The early formed crystals are of phenocrysts and the texture of these crystals is porphyritic texture.
- This crystallization occurs when early-forming plagioclase crystals which are rich in calcium start coating with plagioclase crystals which are rich in sodium.
- On cooling, the magma is then processed in a volcanic eruption, after the eruption the liquid which is left behind will start cooling and forms a porphyritic texture.
Molality is the moles of solute per kg of solvent.
Moles of NH₄Cl = 2.4 / (14 + 4 x 1 + 35.5)
= 0.0448 mole
Molality = 0.0448 / (19.4 / 1000)
= 2.31 m
Barrier islands typically have sand in the beach zone and dune field, and mud in the back-barrier. Overwash deposits sand in the back-barrier.
Barrier islands form in three ways. They can form from spits, from drowned dune ridges or from sand bars. Longshore drift is the movement of sand parallel to the shore caused by the angle of the waves breaking on the beach. ... When a storm such as a hurricane digs an inlet through the spit a barrier island is formed.