To what does the term “linkage” refer?

The term linkage is referred to economic geographic.  

Explanation:

This term refers portray interfirm interdependence.

For others authors Linkages are the interactions and relationships between tasks, functions, departments   and organizations.

In another context these kind of interactions do allow and promote the flow of information and ideas in achieving the objectives of the tourism business.  

the precambrian aged rocks could be found in australia. australia is a region that has a lot of ancient civilization history from million years ago. in this region, there are a lot of recognizable fossils buried in its land which is considered a precambrian-aged rocks