Question

In placer deposits, you are likely to find which of the following minerals?
(A) Mica
(B) Gold
(C) Coal
(D) Bauxite

Answer 1

Hint: Certain minerals may happen as alluvial stores in sands of valley floors and the base of slopes. These stores are called 'placer stores' and by and large contain minerals, which are not eroded by water.

Complete answer:
There are a few assortments of placer stores: stream, or alluvial, placers; eluvial placers; seashore placers; and eolian placers. Stream placers, by a wide margin the most significant, have yielded the most placer gold, cassiterite, platinum, and gemstones. Crude mining most likely started with such stores, and their simplicity of mining and at some point, incredible wealth have made them the reason for a portion of the world's most prominent gold and precious stone "surges."

Stream placers rely upon quickly streaming water for their fixation. Since the capacity to ship strong material differs around the square of the speed, the stream rate has a significant impact; consequently, where the speed diminishes, substantial minerals are stored considerably more rapidly than the light ones. Instances of stream placers incorporate the rich gold stores of Alaska and the Klondike, the platinum placers of the Urals, the tin (cassiterite) stores of Malaysia, Thailand, and Indonesia, and the precious stone placers of Congo (Kinshasa) and Angola.

Eluvial placers structure on hillslopes from endured stores. They are not followed up on by streams however by precipitation and wind, which divert the light materials; consequently, they might be viewed as halfway in the development of stream placers. Models incorporate the prior worked gold stores of Australia and the cassiterite placers of Malaysia.

Therefore, the correct answer is option ‘D’.

Note:Placer stores are framed by surface enduring and sea, waterway or wind activity bringing about the centralization of some significant hefty safe minerals of financial amounts.