Unique and Rare Features
Geologists who studied The Irvine Ranch for the Natural Landmark designation identified many unique and rare features - including fossils of hadrosaurian, or "duckbilled," dinosaurs in the Blind Canyon area. Regionally, the land is an outstanding illustration of the complicated and unique geologic history of the southwestern continental margin of North America.
The exceptionally wide variety of rock types and diversity of fossils exposed on the land captures changing landscapes and evolutionary events with remarkable completeness for a span of nearly 80 million years. The terrain ranges from picturesque coastlines subject to modern erosion and other natural processes, to rugged, uplifted mountains where the geologic history of Southern California is exposed from the late Cretaceous period (65 million to 80 million years ago) to the late Pleistocene period (less than 1 million years ago) and largely intact.