Question
How would a geologist use absolute dating to determine the age of sedimentary layers?
by dating the age of several radioactive elements in a sedimentary rock layer
by dating the age of intrusions and extrusions near a sedimentary rock layer
by comparing the relative ages of several sedimentary rock layers
by identifying fossils in nearby intrusion and extrusions and determining their age
by dating the age of several radioactive elements in a sedimentary rock layer
by dating the age of intrusions and extrusions near a sedimentary rock layer
by comparing the relative ages of several sedimentary rock layers
by identifying fossils in nearby intrusion and extrusions and determining their age
Answers
GPT-4o mini
A geologist would most commonly use **absolute dating by dating the age of intrusions and extrusions near a sedimentary rock layer** to determine the age of sedimentary layers.
While sedimentary rocks themselves cannot be directly dated using absolute dating techniques because they are composed of particles from older rocks, the layers can often be dated by looking at igneous intrusions (sills and dikes) or extrusions (volcanic eruptions) that cut through sedimentary layers. The age of these igneous rocks can be determined using methods such as radiometric dating (e.g., using isotopes of uranium, potassium, or rubidium). By determining the age of the intrusions or extrusions, geologists can then establish a maximum age for the sedimentary layers they intersect.
The other options mentioned—dating radioactive elements in sedimentary rocks, comparing relative ages of sedimentary layers, and identifying fossils—are not effective methods of absolute dating sedimentary layers. Relative dating techniques can give information about sequence but not absolute ages. Fossils can provide relative age but do not provide a precise date, unless they are associated with an igneous layer that can be dated directly.
While sedimentary rocks themselves cannot be directly dated using absolute dating techniques because they are composed of particles from older rocks, the layers can often be dated by looking at igneous intrusions (sills and dikes) or extrusions (volcanic eruptions) that cut through sedimentary layers. The age of these igneous rocks can be determined using methods such as radiometric dating (e.g., using isotopes of uranium, potassium, or rubidium). By determining the age of the intrusions or extrusions, geologists can then establish a maximum age for the sedimentary layers they intersect.
The other options mentioned—dating radioactive elements in sedimentary rocks, comparing relative ages of sedimentary layers, and identifying fossils—are not effective methods of absolute dating sedimentary layers. Relative dating techniques can give information about sequence but not absolute ages. Fossils can provide relative age but do not provide a precise date, unless they are associated with an igneous layer that can be dated directly.