You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "what does each layer of the grand canyon represent?" whose answer is age.
Each document should contain about 30 words, and these documents should contain useful information.

Query: what does each layer of the grand canyon represent
Useful Output:

Doc 1: Carved through sedimentary layers of limestone, sandstone and shale, and into the bedrock of schist and granite, this great chasm stretches 277
Doc 2: Above the Redwall are several other major layers (Supai Group, Hermit Shale, Coconino Sandstone, Toroweap Formation, and Kaibab Limestone, as
Doc 3: In Grand Canyon, TGU is represented where the horizontal layers of the Tapeats Sandstone rest directly on top of the crystalline and more
Doc 4: Rock layers, or strata, in the Grand Canyon illustrate geological time through their individual characteristics and relative positions.
Doc 5: Each letter in the word “dude” represents the first letter of each of the steps in the Grand Canyon's formation. D stands for deposition