geosynclines
/ˌdʒioʊˈsɪnˌklaɪnz/
noun
- Plural of geosyncline; large, long, deep depressions in the Earth's crust where thick layers of sediment accumulate.
- Several geosynclines existed along the edges of ancient continents.
- Geosynclines are often filled with marine sediments and volcanic material.
- The study of geosynclines helps explain how mountain belts develop.