Quartz, zircon, magnetite, gold are major constituents of littoral placers in Shandong province, while shell, ballstone, ilmenite, rutile being secondary.
As he and his colleagues show in a paper posted on arXiv, an online repository, littoral islands may actually exacerbate, rather than diminish, the effects of these waves.
Not many of the strictly littoral animals, or of those which lived on naked submarine rocks, would be embedded; and those embedded in gravel or sand would not endure to a distant epoch.
The explanation, no doubt, is that the littoral and sub-littoral deposits are continually worn away, as soon as they are brought up by the slow and gradual rising of the land within the grinding action of the coast-waves.