| Abstract:The Wanshan mercury deposit, a World-famous mercury district, possesses stratabound characteristics and is of sedimentary-transformed type with the mercury substance derived from wall rocks. The genesis of mercury substance is dealt with in this paper from such aspects as metallogenic series, sedimentary minerals and rocks, sedimentary textures and structures and fossils. The Wanshan ore district has a metallogenic series in Cambrian which consists mainly of P, Mo, V, Ag, K, Zn and Hg, being of sedimentary origin. There exist in Wanshan ore district some sedimentary minerals and rocks, i.e., pyrite, chert, bitumen and organic material , limestone a and ootitic dolomite, which all have fairly high mercury content (Table 3), belonging to sedimentary origin. Some findings may serve as evidence for sedimentary origin of mercury substance, e.g., the existence of micrograined cinnabar in core of sedimentary pyrite nodule, in chert nodule or between crustal laminae of lenses. The living things contain mercury in three different forms: (1) mercury in modern organisms; (2) mercury in biogenic or nonbiogenic deposits; (3) mercury in fossils. Modern creatures contain 0.75 ppm mercury while modern plants l.06 ppm on the average (Table 4); ore deposits also .have rather high mercury content (Table 5), and fossils contains a substantial amount of mercury (Table 6). The author holds the opinion that the above-mentioned low-content sedimentary mercury substance seems likely to have been the source of mercury in low-temperature hydrothermal ore forming stage. |
