CLAY MOBILITY IN LANDSLIDES, VENTURA, CALIFORNIA,
Abstract
Landslides cover about 345 acres or 45 per cent of the eastern producing area of the Ventura Avenue oil field, California. Slide movement is ordinarily slow, being measured in inches or a few feet per year. However, unbalanced forces may culminate in massive movements. The last slide of considerable magnitude occurred in January, 1968, involving more than a million cubic yards, traveling a hundred feet within a few minutes. Fortunately, large fast moving slides are not frequent and occur in limited areas. The oil field landslides occur, for the most part, in Middle Pico Formation (Pliocene), where massive granular sandstones are intercalated at irregular intervals with clay-bearing strata. The sandstone is a sub-angular porous arkose, granular, and poorly cemented. Clay strata are ordinarily thin but contain substantial amounts of less than 2-microns montmorillonite with some illite and an occasional minor content of kaolinite. The clay-water mixture is probably the most important factor in landslide mobility at Ventura, although slope, structure, and compaction require proper consideration. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1968
- Accession Number
- AD0691264
Entities
People
- Isabella M. Drew
- Paul F. Kerr
- Robert A. Stroud
Organizations
- Columbia University