The investigative process by which geologists identify and match sedimentary strata (and other rocks) of the same ages in different areas is called correlation.

Here's a breakdown:

* Correlation: This is the process of establishing the age equivalence of rock units in different locations.

* Stratigraphy: This is the branch of geology that studies rock layers (strata) and their relationships. Correlation is a key part of stratigraphy.

Methods used for correlation:

* Lithological Correlation: Matching rock types and their sequences.

* Fossil Correlation: Matching fossils, especially index fossils, which are unique to specific time periods.

* Geochemical Correlation: Using chemical fingerprints and isotopic dating.

* Paleomagnetic Correlation: Matching magnetic signatures within rocks that reflect the Earth's magnetic field at the time of formation.

Correlation allows geologists to:

* Construct regional geological maps: This helps in understanding the distribution of rock units and their history.

* Reconstruct past environments: Understanding the environment in which rocks formed.

* Identify and understand geological events: Correlation helps in understanding events like volcanic eruptions, tectonic plate movements, and mass extinctions.

Let me know if you'd like more details on any specific correlation technique.