(see Fig. 1 and associated text in Chapter 1) Index map showing relationship of alluvium As concentrations in northernmost Carlin trend to bedrock, Crescent Valley-Independence Lineament (CVIL), and major mineral deposits in north-central Nevada (Theodore et al. 2003). [Reproduced with permission of the Society of Economic Geologists from Theodore et al. (2003), Econ Geol, Vol. 98, Fig. 1, p. 288.]
(see Fig. 2 and associated text in Chapter 1) Regional distribution of As in moss and O- and C-horizon soil samples in the Kola Project area. [Reproduced with permission of Elsevier from Reimann et al. (2009) Appl Geochem, Vol. 24, Fig. 9, p. 1158.]
(see Fig. 3 and associated text in Chapter 1) Global arsenic cycle. Redrawn and simplified from Matschullat (2000), Zhu et al (2014).
(see Fig. 15 and associated text in Chapter 5) Micro-XRF mapping of Fe-Mn ore sample from Val Ferrera sedimentary exhalative deposit, Switzerland. (a) 2.1 million pixel RGB image (3.3 × 4 mm2) shows As speciation as substitution in apatite (ap = apatite, Mn-cc = Mn-calcite, hem = hematite, rm=romeite). Grayscale oxidation state maps of As5+ (b) and As3+ (c) reveal small amounts of As3+ in this highly oxidized system. From Etschmann et al. (2010).
(see Fig. 14 and associated text in Chapter 5) (a–f): Results of bulk As-XAS analysis of low-SO4 (LS) and high-SO4 (HS) columns containing As5+ ferrihydrite and inoculated with a natural, anoxic Fe-reducing microbial consortium (realgar phase forms in HS experiments as shown in panel f); (g–j): qualitative μ-XRF speciation maps of Fe (g, i) and As (h, j) in sediment from LS column (g, h) and HS column …