CAJ | 학술논문

铜陵地区虎山岩体主要由石英二长闪长岩和花岗闪长斑岩组成，属高钾钙碱性系列中酸性侵入岩。本文对虎山岩体进行了LA-ICP-MS锆石U-Pb定年，结果表明，虎山石英二长闪长岩和花岗闪长斑岩侵入时代分别为(143.2±1.2)Ma和(145.3±1.2)Ma，属晚侏罗—早白垩世，与中国东部J-K岩浆事件相呼应，并且，虎山岩体存在两次岩浆侵入活动，早期形成的花岗闪长斑岩的年龄为(145.3±1.2)Ma，与铜陵矿集区瑶山花岗闪长斑岩的年龄(146.0±0.9)Ma在误差范围内一致，晚期形成的石英二长闪长岩为(143.2±1.2) Ma，与区内的铜官山和天鹅抱蛋山岩体的年龄(142±1) Ma和(141.7±1) Ma一致。岩石地球化学及矿物温压计计算结果表明，岩浆结晶的温度为768~838°C、压力为3.44×108~5.42×108 Pa，虎山岩体属幔源岩浆和壳源岩浆混合成因，且混合作用发生在11~18 km的浅位岩浆房。
동릉지구호산암체주요유석영이장섬장암화화강섬장반암조성，속고갑개감성계렬중산성침입암。본문대호산암체진행료LA-ICP-MS고석U-Pb정년，결과표명，호산석영이장섬장암화화강섬장반암침입시대분별위(143.2±1.2)Ma화(145.3±1.2)Ma，속만주라—조백성세，여중국동부J-K암장사건상호응，병차，호산암체존재량차암장침입활동，조기형성적화강섬장반암적년령위(145.3±1.2)Ma，여동릉광집구요산화강섬장반암적년령(146.0±0.9)Ma재오차범위내일치，만기형성적석영이장섬장암위(143.2±1.2) Ma，여구내적동관산화천아포단산암체적년령(142±1) Ma화(141.7±1) Ma일치。암석지구화학급광물온압계계산결과표명，암장결정적온도위768~838°C、압력위3.44×108~5.42×108 Pa，호산암체속만원암장화각원암장혼합성인，차혼합작용발생재11~18 km적천위암장방。
Mesozoic intermediate-acid intrusive rocks in Hushan intrusion of Tongling area belong to the high potassium (K) calc-alkaline series, with main rock types being quartz monzodiorite and granodiorite porphyry. LA-ICP-MS zircon U-Pb dating of Hushan intrusion shows that the emplacement age of quartz monzodiorite and granodiorite porphyry are (143.2±1.2)Ma and (145.3± 1.2)Ma respectively, belonging to Late Jurassic-Early Cretaceous. These data are consistent with eastern China’s J-K magmatic event. In addition, Hushan body has experienced two times of magma intrusion activities. The age of early granodiorite porphyry (145.3±1.2)Ma is consistent with the age of Yaoshan granodiorite porphyry (146.0±0.9) Ma in the Tongling ore district, and the age of late quartz monzodiorite (143.2±1.2)Ma is consistent with that of Tongguanshan and Tianebaodanshan (142±1)Ma,(141.7±1)Ma). From the study of geochemistry and plagioclase-hornblende thermobarometry, the authors conclude that the magma crystallization temperature and the corresponding pressure varied in the range of 768~838° C and 3.44 × 108~5.42 × 108 Pa, respectively. Hushan intrusion was derived from the mixture of the mantle magma and crustal magma, with their corresponding depths being 11~18 km.