The Wentworth scale grain size measures the grain size of sedimentary rock.

Here's a breakdown:

* Sedimentary Rocks: Formed from the accumulation and cementation of sediments (like sand, silt, or clay).

* Grain Size: The size of the individual particles that make up the rock.

* Wentworth Scale: A classification system that categorizes sediment and sedimentary rocks based on their grain size.

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