Answer: It depends on the degradation process and layers of strata above the fossil.
Step-by-step explanation:
The fossil deep beneath the 100 year old strata is expected to contain more amount of mineral content because of the deposition of dead and decaying matter. The chemical conformation of the organism will remain within the upper few layers of the strata, which can be used to analyze the chemical makeup of the organism but the chemical make up is less likely to be traced from organism whose fossil was 200 years old. As the organism is degraded and decomposed to an extent that few traces are likely to be expected which can be used to trace the chemical composition.