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.
Later d is the oldest because it’s at the very bottom and layer a is the youngest
Answer:
Immigration is the act of travelling from one country / nation to other countries and nation in order for an action to be taken.
Explanation:
During winter, the temperature of the water at the bottom of Lake Superior in the Northern United States is 4°C (which stands for Celsius). There is a simple explanation for this; in wintertime, the temperature of Lake Superior often stay above -30°F (which stands for Fahrenheit). Most of the time this lake is covered in ice, rendering a cold temperature but not cold enough for Lake Superior not to experience storms when months like October - December roll around the corner.
It’s A. Sorry if I was incorrect :)