Large Meteorite Impacts III
Original diameter and depth of erosion of the Popigai impact crater, Russia
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Published:January 01, 2005
Previous and recent geological, topographic, drilling, and geophysical data are summarized to acknowledge the 100 km original size of the relatively young and well-preserved multi-ring Popigai impact structure and to estimate the depth of its erosion. The relics of the bedrock rim are traced in the northern and western sectors of the crater, allowing the correct evaluation of the crater diameter. The depth of erosion varies in different crater sectors and concentric zones from 50 to 100 m to 300 m. The most significant erosion occurred on the crater rim. The crater rim has a complex inner structure and is composed of outwardly dragged and uplifted blocks of target rocks overlain by ejecta. During the 35 m.y. that have passed after the crater formation, ∼1000–1200 km3 of unconsolidated allogenic breccias were eroded from the ejecta blanket on the crater rim and from the upper layers of breccias and suevites of the central depression.