Landslides, in fine-grained lake deposits of glacial Lake Hitchcock, Vermont, consist of blocks of material that moved downslope on a layer of fluidlike material. The main cause of these slope landslides was high pore-water pressures. The 6 months preceding the landslides were marked by above-average precipitation leading to saturated soils and elevated pore-water pressures. About the time of the landslides in late May 1984, there were 3 days of rain with an intensity of 1 to 3 in. per day. Many of the 1984 landslides occurred in the vicinity of old landslides.

The landslides have well-developed head scarps and are bounded by either lateral boundary shear planes or en echelon tension fractures. Tension fractures are common throughout the landslides, and in many places they divide the lower portions of the landslide into separate blocks. In many cases, the fluidlike soil from beneath the blocks squeezed into the fissures that developed between the blocks. Lobes of fine-grained, saturated material came out from beneath the slide blocks in the scarp area. These lobes have snouts similar to those found on debris-flow deposits.

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