Palos Verdes Hills

Marine Terraces

Map Satellite

The Palos Verdes Hills, which in the Pleistocene were islands but now are connected to the mainland by sedimentation, are noted for the series of marine terraces that were visible on the slopes. Thirteen and possibly more terraces are present; however, erosion, sedimentation and development have destroyed visible evidence of several. The terraces were apparently formed by the repeated uplifting of the land rather than by the rising and lowering of the sea level.

The four areas included here exhibit samples of the first, second and fourth terraces. In the Lunada Bay area the first and second terraces are easily visible; the latter at an elevation of 40 meters (140 feet) is the widest and best preserved. Both are late Pleistocene in origin. East of Marymount College the fourth terrace is visible. To the north and east of the Portuguese and Inspiration Points region is the Portuguese Bend landslide which had been moving for a number of years and in 1956 slipped and destroyed or severely damaged some 150 houses.

At Second and Pacific is an exposure of the first terrace, which shows the upper Pleistocene Palos Verdes Formation, primarily marine sand and gravels, resting unconformably on the lower Pleistocene Timms Point silts and Lomita marl. This exposure dates the rise of the mountains to the north to the mid-Pleistocene.

Fossils abound, and the area is a classic locality for Pacific Coast Pleistocene molluscs, with over 450 species having been collected from the various terraces.

Integrity: Though disturbed and in the midst of intensive urban development, the areas noted retain identifiable characteristics.

Use: Research, education, observational. Some areas are private.

Ref: Woodring, W. P., et al. 1946. Geology and Paleontology of Palos Verdes Hills, California; U.S. Geo. Prof. Paper No. 207, 145 pp.

January 1977