Varves form only in fresh or brackish water, because the high levels of salt in normal sea water coagulate the clay into coarse grains. Since the saline waters leave coarse particles all year, it is nearly impossible to distinguish the individual layers in salt waters.
An aspartate aminotransferase (AST) test measures the amount of this enzyme in the blood. AST is normally found in red blood cells, liver, heart, muscle tissue, pancreas, and kidneys. AST formerly was called serum glutamic oxaloacetic transaminase (SGOT). Low levels of AST are normally found in the blood. When body tissue or an organ such as the heart or liver is diseased or damaged, additional AST is released into the bloodstream. The amount of AST in the blood is directly related to the extent of the tissue damage.
Generally, the levels of AST ranges from 5 to 43 or 45 units per liter and of ALT from 7 to 56 or 60 units per liter. The upper level tends to be lower in females. A. The serum glutamic-oxaloacetic transaminase (SGOT), now referred to as aspartate aminotransferase (AST) and serum glutamic-pyruvic transaminase (SGPT), called alanine aminotransferase (ALT) are enzymes whose levels are tested to detect liver damage from any cause. They also rise in muscle and heart disease.