Final answer:
Most strata are composed of sediments that form slowly and uniformly through time. These sediments are typically found in sedimentary rocks and igneous rocks formed at the Earth's surface. These rock layers can provide valuable information about the age of the Earth.
Step-by-step explanation:
Most strata are composed of sediments that form slowly and uniformly through time. These sediments are typically found in sedimentary rocks and igneous rocks formed at the Earth's surface, such as lava flows and volcanic fragmental deposits. The layers in these rocks can range in thickness and shape.
These rock layers, also known as strata, can provide valuable information about the age of the Earth. Geologists and archaeologists use the structures of soils and rocks to date phenomena and determine relative positions in a region. They look for stratified layers of artifacts to determine human cultural contexts, with older layers found below cultural layers.