Answer:
The counties of Michigan are organized in a grid pattern because the internal subdivision of the state followed the pattern of surveying established by the Land Ordinance of 1785, which established a rectangular division of the lands of the Northwest Territory, with the objective of facilitating an equal distribution between settlers who would be sent there to populate the region west of the Appalachians.
Thus, the Northwest Territory began to be subdivided into a rectangular shape, and the counties in this region began to take this shape. So when Michigan was established as a state, its counties (as well as those of the other Midwest states) continued to maintain this rectangular shape.
A. Eclipses only occur during full and new moons.
Answer:
potassium-argon dating
Explanation:
Potassium-argon (K-Ar) dating technique is the most appropriate dating method for establishing the age of a volcanic ash. It is most applicable for dating minerals and rocks more than 100,000 years old. It is based on measuring the product of the radioactive decay of an isotope of potassium (k) into argon (Ar). Since potassium is a common element found in many volcanic ash layer, the time since re-crystallization is calculated by measuring the ratio of the amount of argon 40 (Ar-40) accumulated to the amount of potassium 40 (K-40) remaining in these volcanic ashes.
