Retrograde zoning in garnets of Elat-Wadi Magrish metamorphic rocks

Garnets of the progressively metamorphosed Elat-Wadi Watir metasediments show an inverse zonation; MnO concentration is relatively higher at the margins than in the center of the crystals while MgO shows the opposite trend. The zoning is probably caused by a retrograde metamorphism during which the garnet was partly replaced by chlorite. The control of the temperature from which garnets began to cool on zoning effectiveness is discussed.