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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

Passive margin

A transition between continental and oceanic crust that is not an active plate boundary. Many Atlantic margins developed after continental rifting. Sediment accumulation, subsidence and occasional earthquakes can still occur, so passive does not mean completely inactive.

What to look for

NOAA South Atlantic bathymetry. Colour represents seafloor depth, revealing continental margins, abyssal basins and the Mid-Atlantic Ridge.

Related labs

Wilson cycle →
NOAA bathymetry map of the South Atlantic showing continental shelves and the mid-ocean ridge.
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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.