The mazama ash has been dated at numerous locations in the western us to 6900 years old. this means that if anarchaeologist finds the mazama ash in a stratified context, he or she knows that everything above it is less than6900 years old, and everything below it is more than 6900 years old. the mazama ash is an example of a: colluvial sediment. soil horizon. marker bed. sedimentary deposit that has been disturbed, resulting in reversed stratigraphy.

The Mazama ash is an example of a marker bed.

Explanation:

Marker beds are distinct strata that are found in other sites in the same region. They can give evidence to age of sediments in a new site if they’ve been assigned a date in other sites. The Mazama ash is consisted of fragments that were ejected into the air by a volcanic eruption of the Mount Mazama, from Oregon Cascades. It blew up 6900 years ago and the ashes were carried by the wind. When the ash settled, it created a marker bed.

The correct answer is that the statement that best explained the city planning of Harappa is Option D: Harappa was built along the Indus river to encourage travel by water.

Explanation:

One of the things that made the city of Harappa stand out from other cities from the Middle East is that the drainage system would revolutionate the city.