slickenside
1. A lineation on a fault or bedding plane caused by the frictional movement of one rock body against another. The plane may be coated by a mineral, often quartz or calcite, which itself shows striations in the direction of movement.

2. The polished surface left by the passage of a mud slide.

3. In soils, the natural crack surfaces produced by swelling and shrinkage in clayey soils that are high in swelling clays.

slickenside
1. A set of linear marks on a fault or bedding plane caused by the frictional movement of one rock body against another. The plane may be coated by a mineral (often quartz or calcite) which is also striated in the direction of movement.

2. The polished surface left by the passage of a mud slide.

3. In clay soils, the natural crack surfaces produced by swelling and shrinkage.