Pyroclastic rocks are the product of explosive volcanism. They are often felsic (high in silica). Pyroclastic rocks are often the result of volcanic debris, such as ash, bombs and tephra, and other volcanic ejecta.henocrysts are crystals that are larger than the matrix and are identifiable with the unaided eye. Rhomb porphyry is an example with large rhomb shaped phenocrysts embedded in a very fine grained matrix. Volcanic rocks often have a vesicular texture caused by voids left by volatiles trapped in the molten lava.
July 9, 2014. Frozen sperm must be stored in extremely cold temperatures (-196 F), but in order to ensure that the fewest possible sperm are damaged, the freezing must be gradual. Generally, the following procedure is followed:
How Long Can Sperm Live Inside the Body? The issue is often debated with all kinds of theories that support all sorts of arguments. But in actual sense, how long can sperm live inside the body? Depending on different situations, sperms can survive from hours to 7 days inside a female's body. When a man ejaculates inside a woman, very few sperms survive long enough to make an attempt at fertilization. In order to do this, they have to get as far as they can in the cervix. 1  If the sperms fail to make it into the cervix, the acidic conditions in the vaginal canal make it impossible for them to survive longer than a few hours; 2  If they manage to do that, they can survive for up to 3-4 days;