Till

It is deposited some distance down-ice to form terminal, lateral, medial and ground moraines.

[4] It has been known since the careful statistic work by geologist Chauncey D. Holmes in 1941 that elongated clasts in tills tend to align with the direction of ice flow.

Till may also contain lenses of sand or gravel, indicating minor and local reworking by water transitional to non-till glacial drift.

[8] Early researchers tended to prefer the term boulder clay for the same kind of sediments, but this has fallen into disfavor.

[10] Glacial till is mostly derived from subglacial erosion and from the entrainment by the moving ice of previously available unconsolidated sediments.

Bedrock can be eroded through the action of glacial plucking and abrasion, and the resulting clasts of various sizes will be incorporated to the glacier's bed.

[15] Supraglacial deposits and landforms are widespread in areas of glacial downwasting (vertical thinning of glaciers, as opposed to ice-retreat.

They typically sit at the top of the stratigraphic sediment sequence, which has a major influence on land usage.

[18] As a glacier melts, large amounts of till are eroded and become a source of sediments for reworked glacial drift deposits.

Subglacial lodgement tills are deposits beneath the glacier that are forced, or "lodged" into the bed below.

Subglacial deformation tills refer to the homogenization of glacial sediments that occur when the stresses and shear forces from the moving glacier rework the topography of the bed.

Rather than being the product of basal melting, however, supraglacial meltout tills are imposed on top of the glacier.

Initially, the darker colored debris absorb more heat and thus accelerate the melting process.

Properties of flow tills vary, and can depend on factors such as water content, surface gradient, and debris characteristics.

Matching beds of ancient tillites on opposite sides of the south Atlantic Ocean provided early evidence for continental drift.

The same tillites also provide some support to the Precambrian Snowball Earth glaciation event hypothesis.