Nature and Evolution of the Ore-Forming Fluids from Nanmushu Carbonate-Hosted Zn-Pb Deposit in the Mayuan District, Shaanxi Province, Southwest China

Figure 4

Photographs of mineralization characteristics of the Nanmushu Zn-Pb deposit. (a) Vein-type bitumen (Bit(s)) occurs parallel to the country rock. (b) Breccia-type ore, dolomite breccia with Py(s) cemented by later hydrothermal mineral. (c) Breccia-type ore, yellow sphalerite + quartz (stage I) and brown sphalerite + quartz (stage II) are cemented by the dolomite breccia. (d) Vein-type ore, assemblages of coarse-grained galena with minor sphalerite as a vein (stage II) crosscut the early sphalerite vein (stage I). (e) High-grade massive ore, assemblages of coarse-grained galena and sphalerite (stage II). (f) Bit(a) associating with contemporary sphalerite occurs in vein (stage II). (g) Later Py(b) surround the early Sp(b) in stage II. (h) Sphalerite and galena as breccia (stage II), cemented by late barite + calcite + quartz + bitumen (stage III). (i) Abundant Bit(b) filled in the interspace of quartz in stage III. Bit, bitumen; Brt, barite; Cal, calcite; Dol, dolomite; Gn, galena; Py, pyrite; Qz, quartz; Sp, sphalerite.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)