tailieunhanh - Tuổi đồng vị U-Pb zircon các thành tạo magma xâm nhập phía bắc mỏ Pác Lạng, huyện Ngân Sơn, tỉnh Bắc Kạn và mối liên quan với quặng hóa vàng - thạch anh - sulfua

Bài viết trình bày những kết quả nghiên cứu mới về tuổi đồng vị U-Pb zircon và đặc điểm thạch học của các thành tạo xâm nhập phía bắc mỏ Pác Lạng cũng như mối liên quan giữa chúng với quặng vàng-thạch anh-sunfua khu vực. Kết quả nghiên cứu cung cấp nhưng thông tin quan trọng cho việc đánh giá toàn diện hơn về lịch sử tiến hóa địa chất vùng Pác Lạng | 42 Journal of Mining and Earth Sciences Vol. 63 Issue 2 2022 42 - 51 U-Pb ages of zircon from an intrusion located at the northern part of Pac Lang deposit Ngan Son district Bac Kan province and its relation to mineralization of gold- quartz - sulfide Dat Van Nguyen 1 Tin Duc Quach 1 Luong Duc Pham 2 Hieu Trung Pham 3 Tung Dinh Ta 1 1 Viet Nam Institute of Geosciences and Mineral Resources Vietnam 2 Vietnam Union of Geological Sciences Vietnam 3 Faculty of Geology VNUHCM - University of Science Vietnam ARTICLE INFO ABSTRACT Article history The geological investigation indicated that the structure of Pac Lang gold Received 13th Nov. 2021 mining has been constrained by a small intrusion about 1200 m in length Accepted 24th Feb. 2022 and 150 200 m in wide which elongates east - west along the provincial Available online 30th Apr. 2022 highway of DT209. This block includes two intrusive phases in which 1 Keywords the first phase consists of grabrodiabas and 2 the second phase is Isotopes U-Pb porphyry granitic rock. According to the geological map of Bang Khau - Zircon Yen Lac at a scale of 1 it has been considered Ban Sieu complex µD3 bs1 containing gabbro grabrodiabas semplaced during the Late Intrusion located Devonian. A U-Pb LA-ICP-MS zircon age of 250 270 Ma mean Gold - quartz - sulfide ores Ma was obtained for a sample of porphyry granitic and Ngan Son Bac Kan. 250 257 Ma mean Ma was obtained for a sample of gabrodiabas . These results have pointed out that the timing emplacement of magma intrusion in this study is much younger than that in previous studies. It is close to the ages of intrusive rocks found in Song Hien interior rift and the ages of intrusive rocks found in the Song Hien interior rift proposed by other geologists. Therefore it can be classified into the late Permian - early Triassic P3-T1 Cao Bang complex of ultramafic - mafic - felsic of Song Hien interior rift. Based on the hydrothermal transformation