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coral growth lines

coral growth lines All corals that have a calcified outer wall display minute growth lines on their outer surfaces. The carbonate is secreted by symbiotic algae (zooxanthellae) which, responding to day and night, create a series of diurnal growth increments. Studies on Devonian isolate corals indicate a 400-day year and, therefore, a 22-hour day. Post-Devonian data confirm a near-linear deceleration of the Earth's rotational velocity towards the present 24-hour day. The number of daily growth lines can therefore be used in a crude way to calibrate the geologic record.

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"coral growth lines." A Dictionary of Earth Sciences. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"coral growth lines." A Dictionary of Earth Sciences. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/coral-growth-lines

"coral growth lines." A Dictionary of Earth Sciences. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/coral-growth-lines

coral growth lines

coral growth lines Minute growth lines on the outer surfaces of all corals that have a calcified outer wall. The carbonate is secreted by symbiotic algae (zooxanthellae) which, responding to day and night, create a series of diurnal growth increments. Studies on Devonian isolate corals indicate a 400-day year and, therefore, a 22-hour day. Post-Devonian data confirm a near-linear deceleration of the Earth's rotational velocity towards the present 24-hour day. The number of daily growth lines can therefore be used in a crude way to calibrate the geologic record.

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"coral growth lines." A Dictionary of Ecology. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"coral growth lines." A Dictionary of Ecology. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/coral-growth-lines-0

"coral growth lines." A Dictionary of Ecology. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/coral-growth-lines-0