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Geolens

Glossary

417 words used in the labs.

Find a term from the labs, understand the process behind it, and see how it appears in the landscape. Each entry connects an explanation with a real observation and a model you can explore.

Term

Till

Unsorted sediment deposited directly by glacier ice, often containing a mixture from clay to boulders. Its poor sorting distinguishes it from many meltwater deposits reworked by flowing water. Till can form several types of glacial landform.

What to look for

A natural exposure of glacial till. Ice deposits a mixture of grain sizes directly, often without the sorting produced by flowing water.

Related labs

Glacial landforms →Mass movement →
An exposed bank of poorly sorted glacial sediment containing stones of several sizes.
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Explore further with USGS water glossary · USGS volcano glossary · NPS glacial geology · NASA Earth facts. Photograph acknowledgements are collected on the Image credits page.