John Turbeville

MiraCosta College

 

Stop 2 is at the overview area to the middle of the sea-cliff on Trail #1.  At this stop, we will look at slumping in the Monterey Formation. The slumping (1) is progressively moving the sea-cliffs toward the campground, the railroad and I-5.  This type of mass wasting (slumping (2)is common in soft sediments.  

 

This shot is looking north-west from Trail#1. You can see the large slumps in the foreground. These areas are underlain by the very soft Monterey Formation. The Cristianitos Fault is located where you see the cliff as being near vertical directly INLINE with the nuclear powerplant. On the other side of the Cristianitos Fault, the sea-cliff is near vertical as the base is composed of the tanish San Mateo Formation.

 

This shot is looking south-east from Trail #1. This area is underlain by the very soft Monterey Formation. Large slumps dominate the landscape here. You can see some backwards rotation in the block that is in the middle of this picture.

 

Walking down the trail to the beach you pass some large exposures of alluvial deposits. These form the upper portion of the sea-cliffs in the San Onofre area. They are locally derived and very young deposits.

 

Notice how poorly sorted and angular the rock fragments are in the alluvial deposits.

Home Introduction Fieldtrip Stops Deliverables