Question

relative and absolute dating of fossils
classify the following characteristics depending on what type of dating is described. not all choices will be used.
relative dating
absolute dating
uses the radioactive decay of ^{14}c
dating is made possible by comparing the presence of index fossils with fossilized remains
uses k-ar to date newer remains
uses k-ar to date older remains
dating is made possible when a fossil is sandwiched between sediment layers which have fossils of a known age
uses radioactive decay of ^{14}c
based on the law of superposition
based on the law of sedimentarianism
accurate for fossils up to 600,000 years old
dating is made possible by comparing the isotopic ratios of living organisms to those of fossils

Explanation:

Relative Dating:

• Dating is made possible by comparing the presence of index fossils with fossilized remains: Index fossils are used to correlate the age of rock layers, a key part of relative dating.
• Dating is made possible when a fossil is sandwiched between sediment layers which have fossils of a known age: Relies on the position of fossils in sediment layers (with known - age fossils) to determine relative age.
• Based on the law of superposition: The law of superposition (older layers at the bottom, younger at the top) is fundamental to relative dating.
• Based on the law of sedimentarianism: (Assuming it's a typo for sedimentation - related principles) Related to how sediment layers form and are used in relative dating.

Absolute Dating:

• Uses the radioactive decay of \(^{14}\text{C}\): Carbon - 14 dating is an absolute dating method for relatively young fossils (up to ~60,000 years, though the option says 600,000 which might be a typo, but still a form of absolute dating).
• Uses the radioactive decay of \(^{40}\text{K}\) (assuming \(^{40}\text{p}\) is a typo for \(^{40}\text{K}\)): Potassium - argon (K - Ar) dating uses potassium - 40 decay, and K - Ar is used for older remains.
• Uses K - Ar to date older remains: K - Ar dating is suitable for dating older geological materials (including fossils in them).
• Accurate for fossils up to 600,000 years old: Carbon - 14 dating has a limit (more accurately ~60,000, but the option is given) and is an absolute method.
• Dating is made possible by comparing the isotopic ratios of living organisms to those of fossils: This is related to methods like carbon - 14 dating (comparing \(^{14}\text{C}\) ratios in living and fossilized organisms), an absolute dating technique.
• Uses K - Ar to date newer remains is incorrect for K - Ar (it's for older), so it should not be in absolute dating.

Answer:

Relative Dating:

• Dating is made possible by comparing the presence of index fossils with fossilized remains
• Dating is made possible when a fossil is sandwiched between sediment layers which have fossils of a known age
• Based on the law of superposition
• Based on the law of sedimentarianism

Absolute Dating:

• Uses the radioactive decay of \(^{14}\text{C}\)
• Uses the radioactive decay of \(^{40}\text{K}\) (assuming \(^{40}\text{p}\) is a typo)
• Uses K - Ar to date older remains
• Accurate for fossils up to 600,000 years old
• Dating is made possible by comparing the isotopic ratios of living organisms to those of fossils