What is the mineral deposited in the sands of valley floors and the base of hills?

Option 2 is the correct answer: The mineral deposited in the soil of the lower hills and valleys in the sand are called Placer deposits.

• Placer deposits are formed by the concentration of a particular metal or mineral over a period of time.
• The river while flowing through the rocks extract the minerals from there and they are deposited downstream under the influence of gravity.
• These deposits are a result of depositions made by water, therefore placer deposits are found in or near subaqueous environments.
• They are found in or near water bodies also in the sands of ancient river channels, dried valleys, beaches and coasts.
• Generally, the inert metal like Gold and Platinum forms these kinds of deposits.
• The reaction resistant ores like magnetite, monazite, zircon and rutile are also found in placer deposits.
• The coastal plains of Alaska, India, NewZealand, Indonesia and South Africa are rich in placer deposits.