What does the term 'loess' refer to?

The term 'loess' refers to a deposit made of fine clay and silt, which is typically formed by the accumulation of wind-blown dust. This type of soil is characterized by its rich mineral content and excellent fertility, making it ideal for agriculture. Loess deposits are often found in regions such as the Great Plains of the United States and parts of China, where they have been essential for supporting various agricultural practices.

Understanding loess is crucial in the context of world history, as the rich agricultural lands formed from these deposits have supported civilizations throughout history, influencing settlement patterns and economic development. The other options do not accurately define loess, as it is not related to artifacts, writing systems, or farming methods directly, but rather to the geological and agricultural significance of the soil itself.