Explain the formation of fold mountains (3 marks)

Fold mountains form on convergent (or collision) plate boundaries. They push up layers of accumulated sediment in the sea into folds. Examples are the Himalayas and Andes. The layers of sediment are accumulated in depressions (called geosynclines) on the sea floor over millions of years. The heavy weight of the water causes the layers of deposited sediment to compact into sedimentary rockThen as two continental plates move together at a convergent (or collision) plate boundary, the rock layers are compressed and are forced upwards. The peaks are called anticlines, and troughs are known as synclines.