Permineralization and carbonization are not methods of correlating rock units. Instead, they are fossilization processes that can help in understanding the composition and structure of ancient organisms.
Permineralization is a process in which minerals, such as silica or calcite, fill in the pore spaces of a fossil. This can preserve delicate structures within the fossil and provide clues about the environment in which the organism lived.
Carbonization, on the other hand, is a process in which an organism is compressed and heated over time, causing the organic material to be reduced to a thin layer of carbon. This can create a highly detailed impression of the organism in the rock.
To correlate rock units, geologists typically use a variety of techniques, such as analyzing the relative positions of rock layers, studying the types of fossils found in each layer, and examining the mineral content and age of the rocks. By comparing these characteristics, geologists can determine how different rock units are related to one another and create a geologic time scale that shows the relative ages of different rock layers.