Table 2. Positions of Features Related to Hydrated Silicates (e.g., Clay Minerals) in Samples From the Bulk Rock Compared With Band Centers for End-Member Smectite Compositionsa Sample 2nuOH (mum) nuOH + Deltam-OH (mum) 2nuOH (mum) nuSi-O (cm-1) Delta(Al,Si)-Si-O (cm-1) hvalfj011 1.415 2.297, 2.319 2.76 1038 527sh, 472 hvalfj017 1.415 2.215 2.76 1045 520, 466 hvalfj025 1.425 2.293 2.792 1061 519, 448 hvalfj054 1.42 2.298 (broad) 1042-1034 538sh, 460 icel009 1.410, 1.440 2.302 2.81 1053, 987 500, 453 icel010 1.410, 1.440 2.302 2.81 1185, 1024 - Nontronite 1.43 2.28-2.29 2.80 1056-1068 510-515, 455-440 Saponite 1.38-1.39 2.31-2.32 2.72 1037 475-480 Montmorillonite 1.41 2.21 2.76 1055-1070 (1137) 525-535, 470-475 aBand centers were determined from continuum removed spectral data.