Shale often contains fossils of leaves.
Question: If the gastropods listed in line 3 and line 6 were collected from shale containing leaf fossils what would their possible age be?
Question: Could you use radiocarbon dating to assign a numerical date/age to this rock unit? Explain.
To determine the possible age of the gastropods collected from shale containing leaf fossils, we can make use of relative dating techniques. Relative dating is a method that allows us to determine the age of a fossil or rock unit relative to other fossils or rock layers.
In this case, since shale often contains fossils of leaves, we can assume that the gastropods found in line 3 and line 6 were collected from the same shale formation that also contains leaf fossils. Therefore, their possible age can be determined by looking at the age of the shale formation.
There are several methods to establish the age of a shale formation, such as biostratigraphy, lithostratigraphy, and radiometric dating. Biostratigraphy involves comparing the fossil assemblages found in the shale unit with known fossil sequences to estimate its age. Lithostratigraphy, on the other hand, relies on the examination of the sedimentary layers and their characteristics to correlate them with known age sequences.
Radiometric dating, however, may not be applicable in this case to assign a numerical date or age to the shale unit. Radiocarbon dating, which is the most widely known radiometric dating method, is suitable for determining the age of organic materials that are up to about 50,000 years old. However, shale formations usually contain inorganic materials such as clay minerals, silt, and fossilized organic matter, which are not suitable for radiocarbon dating.
Instead, radiometric dating methods like uranium-lead dating or potassium-argon dating could be used to assign a numerical age to the shale unit if applicable minerals are present. These methods rely on the decay of radioactive isotopes within the minerals to estimate the age of the rock. However, the availability of these suitable minerals for dating would depend on the specific composition and characteristics of the shale formation.
In summary, to estimate the possible age of the gastropods collected from the shale containing leaf fossils, relative dating methods like biostratigraphy or lithostratigraphy would be more suitable. Radiocarbon dating would not be applicable for providing a numerical age for this particular rock unit, but other radiometric dating methods could be employed if appropriate minerals are present in the shale formation.