-An extensive depression called a geosycline is formed on the surface of the earth
-The geosycline is filled with water to form a sea
Diagram:
![testpaper13620211839.JPG](../Uploads/LessonImages/testpaper13620211839.JPG)
-The surrounding land masses are eroded and the resultant materials are deposited in the geosycline in layers
-Accumulation and weight of sediments causes the floor of the geosycline to subsidise further.
-Further subsidence of the geosycline triggers off compressional forces, drawing higher grounds close
-The layers of sediment in the geosycline are then
folded bedding upwards to form mountains
Diagram:
![testpaper1362021842.JPG](../Uploads/LessonImages/testpaper1362021842.JPG)