In Cherokee Nation, the Court ruled that it lacked jurisdiction (the power to hear a case) to review claims of an Indian nation within the United States. In Worcester, the Court ruled that only the United States, and not the individual states, had power to regulate or deal with the Indian nations.
provides the conduits for air and water exchange and houses roots and microbes. Soil. porosity is the amount of pore volume (% of pore space). A medium textured, well-aggregated. soil contains about 50% pore space and is in good condition for plant growth when the pores. hold an equal distribution of air and water.
These rocks often have high porosity, and are usually âhigh permâ too. Porosity and permeability are absolutely necessary to make a productive oil or gas well. The petroleum geologist must stay focused on the porosity and permeability of the prospective reservoir. Porosity consists of the tiny spaces in the rock that hold the oil or gas. Permeability is a characteristic that allows the oil and gas to flow through the rock. You need both porosity and permeability to make a producing oil or gas formation. Porosity. Porosity of a rock is a measure of its ability to hold a fluid. Mathematically, porosity is the open space in a rock divided by the total rock volume (solid + space or holes).