Term 'Zwischengebirge' is associated with:

Question

Accepted Answer

The term 'Zwischengebirge' is associated with Kober's Geosynclinal Orogen theory because Kober used this term to describe the relatively undisturbed, rigid blocks or massifs that lie between the folded mountain ranges formed from geosynclines. In Kober's theory, geosynclines (long, narrow, subsiding troughs) accumulate sediments over vast periods. During orogenic (mountain-building) phases, these geosynclinal sediments are compressed and folded into mountain ranges. The 'Zwischengebirge' are the stable, resistant areas that remain relatively unaffected by the folding and faulting processes occurring in the geosynclines. They act as buttresses or resistant blocks around which the mountain ranges are formed.

Here's why the other options are incorrect:

1. **Thermal contraction theory of Jeffrey:** Jeffrey's thermal contraction theory focuses on the Earth's cooling and shrinking, leading to crustal wrinkling and mountain formation. It doesn't specifically use or define the term 'Zwischengebirge'. His theory is more about the overall mechanism of mountain building due to global cooling, not the specific structural elements like the stable blocks between mountain ranges.

2. **Daly's sliding continental theory:** Daly's theory proposes that continents slide over the Earth's mantle due to gravity. While it addresses continental movement and its potential role in mountain building, it doesn't incorporate the concept of 'Zwischengebirge' as a key element in its explanation. Daly's focus is on the large-scale movement of continents, not the specific structural features within orogenic belts.

3. **Radioactivity theory of Joly:** Joly's theory suggests that radioactive heat within the Earth causes periodic melting of the sub-crustal material, leading to crustal uplift and mountain building. While radioactivity is a factor in Earth's internal processes, Joly's theory doesn't directly relate to the concept of 'Zwischengebirge' as stable blocks within orogenic zones. His theory focuses on the driving force behind uplift, not the resulting structural features.