矿床地球化学国家重点实验室知识库

This chapter compiles the geology and geochronology of numerous ores, including graphite, phosphorite, the Lake Superior type BIFs, marble, boron, magnesite, and lead-zinc deposits, hosted in 2.5–1.8 Ga stata from the North China Craton (NCC) and elsewhere, and thereby provides insights into understanding the mineralization of the early Paleoproterozoic metallogenic explosion in NCC. These mineralized records, accompanied with the blooms of biological photosynthesis (indicated by graphite, phosphorite deposits, organics in black shale), suggested different mineralizations, which responded to different stages of dramatic Earth’s environmental changes characteristic of the Great Oxidation Event (GOE). These changes includes that the early-stage hydrosphere oxidation (2.5–2.3 Ga), indicated by numerous development of the Lake Superior type BIFs; through the turnpoint from hydrosphere to atmosphere oxidation (2.3–2.25 Ga), indicated by the 2.29–2.25 Ga Huronnian Glaciation Event (HGE) and devoid of Rand-type Au–U deposits, to the late-stage atmospheric oxygenation, followed by 2.25–1.8 Ga sediments of thick-bedded carbonates strata and related deposits (e.g., marble, magnesite, boron, and lead-zinc deposits), the 2.25–1.95 Ga red beds, 2.22–2.06 Ga δ¹³C_carb positive excursion (Lomagundi/Jatulian Event), as well as the prevail of black shales at 2.0–1.7 Ga and disappear of BIFs at ca. 1.8 Ga.