Stromatolies form	Contact structure						Turbulence low high	Under the tide Middle the tide On the tide
Stromatolies form							Turbulence low high	Under the tide Middle the tide On the tide
				√	√	√
	√	√	√		√	√
	√	√	√	√	√	√
	√	√		√
	√	√		√		√
	√	√	√
	√	√