Slow Heart Beat (Bradycardia) An abnormally slow sinus heart rate is called the âsick sinus syndromeâ and, if severe, results in symptoms of fatigue. In some such cases a permanent pacemaker is needed to be implanted to generate a normal heart rate. Many people with sick sinus syndrome also develop atrial fibrillation.
Petrified wood (from the Greek root petro meaning rock or stone; literally wood turned into stone) is the name given to a special type of fossilized remains of terrestrial vegetation. It is the result of a tree or tree-like plants having completely transitioned to stone by the process of permineralization.lements such as manganese, iron, and copper in the water/mud during the petrification process give petrified wood a variety of color ranges. Pure quartz crystals are colorless, but when contaminants are added to the process the crystals take on a yellow, red, or other tint.
The most famous locality for observing petrified wood is Petrified Forest National Park near the community of Holbrook in northeastern Arizona. About 225 million years ago this area was a lowland with a tropical climate and covered by a dense forest.n accumulation of petrified logs in a gulley at Petrified Forest National Park. At the top of the gulley a pedistal log is suspended on a column of Chinle Formation. When the Chinle weathers away the log will be lowered to the ground surface.