Comment: 05:15 - 06:03 (00:48)
Source: Annenberg/CPB Resources - Earth Revealed - 17. Sedimentary Rocks: The Key to Past Environments
Keywords: "Dee Trent", "sedimentary rock", "clastic sediment", deposition, water, river, mountain, canyon, valley, "coarse grained sediment", "fine grained sediment", sandstone, siltstone, ocean, sand, shoreline, mud, clay
Our transcription: Deposition typically occurs wherever there's a slowing of the running water.
A good example would be at the base of a steep mountain range, where the rivers are coming out of a deep canyon into a flat valley.
Now, the kinds of materials that would be formed there would be very coarse grained.
The further away you get from the front of the mountain range, the finer the grained is the sediment being carried.
Like consequently you would get finer grained sandstones or siltstones further away.
The same thing happens in an ocean.
Where a river enters the ocean, the first things that drop out are the course grained materials, generally sand size material.
Further out to sea there will be fine grained material.
Well, the sands are usually found on the coast shoreline areas, where the muds and the clays would be further offshore.
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