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Paper No. 7
Presentation Time: 8:00 AM-6:00 PM

MATERIALS BY OCEAN IMPACTS


MIURA, Yasunori, (Science Division), Yamaguchi University, Chuou 4-chome 1-23, Yamaguchi, 753-0073, Japan, yasmiura@yamaguchi-u.ac.jp

Introduction: Main impact materials are studied on dry lands which can be applied to water-less Moon, Mars and Asteroids. The present purpose is to elucidate microscopic evidences of ocean-water impacts which are formed during ocean-water condition of salty water and sea-bottom rocks.

Compositions and materials at impact on ocean water: Materials from compositions at ocean–impact are classified as 1) original meteoroids (by smaller impacts obtained in sea-sediments), 2) spherules with meteoritic compositions formed during air collision (collected in sea-sediments), 3) carbon-rich materials (including carbonates) from carbonate sea bottom-rocks on pre-formed rock of breccias, and 4) chlorine-rich materials (including halite minerals) from Na, Cl-bearing sea-water during evaporation-solid process. New materials formed after sea-impact condition of the above 3) and 4) are discussed in this paper.

Micro-size of impact materials: Almost all impact materials on dry and ocean-bottom impacts are remained as impact rocks of breccias in naked-eye sizes. However impact materials formed during dynamic reaction with quenched process are normally less than 1μm in size which should be analyzed by special electron microscopy with EDX analyzer unit for analyses of nano-materials for 100nm size.

Carbon-bearing impact materials: Nano-materials of carbon-bearing with various-range compositions with carbon and meteoritic elements are formed from shallow sea-bottom carbonate rocks as target rocks or mixed rocks during impact.

Chlorine-bearing impact materials: Nano-materials of chlorine-bearing with various-range compositions with chlorine and meteoritic elements are formed from salty sea-water composition during evaporation of impact, which are remained in quenched glassy spherule and breccias.

Example for ocean impact with carbon- and chlorine-bearing particles: Fine carbon- and chlorine-bearing particles as ocean-impacts are founds in samples of the drilled core and glasses of the Takamatsu (Kagawa, Japan), the Akiyoshi (Yamaguchi, Japan), Libyan desert silica glasses LDSG (Libya, Africa), Congo diamond (Congo, Africa) and the KT and PT geological boundary samples (Spain and Meishan China) .

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