Which series refers to rocks younger than the Nevadan Orogeny?

The series that refers to rocks younger than the Nevadan Orogeny is the Subjacent Series. The term "subjacent" generally indicates a position that is situated beneath something else, in this case, denoting rocks that are deposited after a significant geological event—in this context, after the Nevadan Orogeny which occurred from the Late Jurassic to the Early Cretaceous period.

This orogeny led to extensive mountain-building processes that shaped the geology of California, and the Subjacent Series consists of sedimentary and volcanic rocks that were formed in the geological timeframe following these orogenic events. Thus, identifying these as younger rocks appropriately relates to their chronological position in relation to the orogeny.

The other series mentioned do not accurately reflect the relationship to the Nevadan Orogeny as the Subjacent Series does. Understanding this geological relationship is crucial for geological mapping, stratigraphy, and understanding the tectonic history of the region.