慶南 東南部地域 鐵鑛床의 成因에 關한 硏究

• 영문명: Genesis of iron ore deposits in the south-eastern part of Gyeongnam Province, Korea
• 발행기관: 대한자원환경지질학회
• 저자명: Young Kyun Woo(禹榮均)
• 간행물 정보: 『자원환경지질』21권 1호, 45~56쪽, 전체 12쪽
• 주제분류: 자연과학 > 지질학
• 파일형태: PDF
• 발행일자: 1988.02.28

영문 초록

Many hydrothermal skarn-type iron ore deposits including Mulgeum, Yangseong, Maeri and Kimhae mines are distributed in the south-eastern Gyeongnam Province, Korea. The deposits are magnetite veins which occurred in propylitized andesitic rock near the contact with late Cretaceous Masanite. Symmetrical zoned skarns are commonly developed around the magnetite veins. The order of the skarn zones from the vein is garnet-quartz skarn, epidote skarn, and epidote-orthoclase skarn. The garnets include isotropic or anisotropic andradite(Ad100~70), and the epidotes are composed of pistacite(Ps21~31) Fe contents of the epidotes generally increase toward the magnetite veins. Epidotes and garnets often show compositional variations from grain to grain, that is, their Fe and Al contents vary inversely. This suggests that the variations depend mainly upon fo₂ during the skarnization. Oxygen and carbon isotope analyses of minerals from andesitic rock, micrographic granite, major skarn zones and post-mineralization zones were conducted to provide the information on the formation temperature, the origin and the evolution of the hydrothermal solution forming the iron ore deposits. Becoming more distant from the ore vein, temperatures of skarn zones represent the decreasing tendency, but most δO¹⁸ and δO¹⁸H₂O values of skarn minerals represent no variation trend, and also the values are relatively low. Judging from all the isotopic data from the ore deposits, the major source of hydrothemal solution altering the skarn zones and precipitating the ore bodies was magmatic water derived from the more deeply seated micrographic granite. This high temperature hydrothermal solution rising through the fissures of propylitized andesitic rock was mixed with some meteoric water, and the extensive isotopic exchange occurred with the propylitized andesitic rock. During this process, the temperature and δO¹⁸H₂O value of hydrothermal solution were lowered gradually. At the stage of iron ore precipitation, because after all the alteration was already finished, the oxygen isotopic exchange with the wall rock was nearly not taken. The relatively high δO¹⁸ and δ O¹⁸H₂O, and relatively low δC¹³ values of calcites of post mineralization stage, are the results of leaching of the high δO¹⁸ chert xenolith in the andesitic rock and low δC¹³ andesitic rock.

목차

Abstract

序言

地質

鑛床

流體包有物硏究

酸素 및 炭素同位元素比 分析硏究

考察

結言

參考文獻