Data report: Chemical and isotopic (s, sr) composition of anhydrite from ODP Leg 193, PACMANUS hydrothermal system, manus basin, papua new guinea

Sr and S isotope data as well as trace element data for anhydrite samples from Sites 1188 and 1189 in the PACMANUS hydrothermal area are presented here. ⁸⁷Sr/⁸⁶Sr ratios range from 0.7050 to 0.7086, suggesting that the anhydrites precipitated from fluids that were variably influenced by entrained seawater (0%-89%). δ³⁴S values range between 18.1‰ and 22.5‰, indicating the main source of sulfate is seawater that may be affected to small extents by sulfide oxidation or magmatic sulfate input (δ³⁴S < 21‰) and minor sulfate reduction (δ³⁴S > 21‰). Rare earth element (REE) concentrations are highly variable, particularly at Site 1188. Chondrite-normalized REE pattern shapes comprise light REE enriched, light REE depleted, mid-REE enriched, and variable positive and negative Eu anomalies. Significant correlations between trace element and isotopic compositions are lacking. Anhydrite from Site 1188, a site of diffuse venting, has systematically lower δ³⁴S and higher Sr contents and somewhat lower average ⁸⁷Sr/⁸⁶Sr than anhydrite from Site 1189. This is possibly a consequence of the different fluid flow regime with diffuse flow at Site 1188 and focused flow at Site 1189.