Folding

Folding


# Folding is the process through which crustal rocks are bent.
# It produces anticlines (upfolds) and synclines (downfolds).
# Folding can produce very large mountains such as the Himalayas and the Rockies.
# Orogenesis is the process through which mountains are created. There are 3 periods of recent mountain building:

1. Caledonian Period:310 million years ago. Most mountains created during this period have been destroyed through denudation. Remnants are the Scottish Highlands and the mountains of Scandinavia.
2. Hercynian Period:240 million years ago. Examples include the Cape Ranges of South Africa, the Appalachians of the United States and Welsh mountains of the UK.
3. Alpine Period:30 million years ago. Examples include the Alps and the Andes. Mountains created during this period are the highest because the have not yet been reduced by denudation.

# Folding takes place in three main stages:

1. Initial bending of rocks as plates come together
2. Simple Anticlines and Synclines are created.
3. Formation of fold mountains-asymmetrical folds.
4. Breaking of the folding results in faults/depressions.

# Peneplaination is the reduction of fold mountains to a level plain called a peneplain.