Cretaceous Seawater Sulfur Isotopic Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Cretaceous Seawater Sulfur Isotopic Data LAST UPDATE: 8/2006 (Original receipt by WDC Paleo) CONTRIBUTOR: Adina Paytan, Stanford University IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2006-077 SUGGESTED DATA CITATION: Paytan, A. et al. 2006. Cretaceous Seawater Sulfur Isotopic Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2006-077. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Paytan, A., M. Kastner, D. Campbell, and M.H. Thiemens. 2004. Seawater Sulfur Isotope Fluctuations in the Cretaceous. Science, Vol. 304, pp.1663 - 1665, 11 June 2004. ABSTRACT: The exogenic sulfur cycle is tightly coupled with the carbon and oxygen cycles, and therefore a central component of Earth's biogeochemistry. Here we present a high resolution record of the sulfur isotopic composition of seawater sulfate for the Cretaceous. The general enrichment of isotopically light sulfur that prevailed during the Cretaceous may have been due to increased volcanic and hydrothermal activity. Two excursions toward isotopically lighter sulfur represent periods of lower rates of pyrite burial, implying a shift in the location of organic carbon burial to terrestrial or open ocean settings. The concurrent changes in seawater sulfur and inorganic carbon isotopic compositions imply short-term variability in atmospheric oxygen partial pressure. GEOGRAPHIC REGION: Global PERIOD OF RECORD: Cretaceous, 130 - 65 Million YBP. FUNDING SOURCE: National Science Foundation (USA). DESCRIPTION: Marine barite was used to reconstruct the seawater sulfate S isotope curve. Barite forms in the water column in micro-environment containing decaying organic matter, acantharian shells and siliceous remains. This authigenic barite forms microcrystals or aggregates, ranging from 0.5 to 5 mm. Marine barite crystals have been previously shown to accurately record the seawater S isotope ratio which due to the long residence time of S is at any given time is homogenous throughout the ocean. Barite was separated from several Deep Sea Drilling and Ocean Drilling Program cores from pelagic settings (Table S1) using a sequential leaching technique modified from Paytan et al. 1993 and Eagle et al. 2003. The procedure includes reaction with acetic acid, sodium hypochlorite, hydroxylamine, and an HF-HNO3 mixture. To avoid potential oxidation of sulfide to sulfate and precipitation as barite the procedure was done in a glove bag under a nitrogen atmosphere. Barite samples were thoroughly tested to exclude any barite suspected to be of diagenetic origin based on crystal structure and Sr isotopes. S isotopes were analyzed either by continuous-flow mass spectrometry or by conversion to silver sulfide and fluorinated to SF6. Sulfur isotope results are reported relative to the Canyon Diablo Troilite standard, with a standard deviation (2s) of + 0.3 per mil. Age models for the samples are based on a combination of biostratigraphy and Sr isotopes. DATA: Paytan et al. 2004 Cretaceous Seawater Sulfur Isotopic Data Leg 32 Site 305, 32º 00 N, 157º 51 E, 2921 m Core – Section, Interval (cm) Age d34S(‰) 15-2, 52-56 65.17 18.95 15-2, 136-14 65.23 18.94 16-2, 114-11 66.02 18.76 17-2, 31-37 66.75 18.8 19-2, 112-115 68.65 18.85 19-2, 112-115 duplicate 68.65 18.85 20-2, 14-131 70 18.82 21-2, 63-66 71.31 19.09 23-1, 60-70 74.19 19.14 23-2, 76-79 74.4 19.33 23-6, 56-59 75.62 19.3 24-4, 90-95 76.43 19.14 25-2, 108-110 78.75 19.14 26-2, 45-50 80.32 19.04 27-2, 80-85 81.97 18.87 28-2, 73-77 83.63 18.36 28-2, 85-90 83.7 18.4 31 CC 88.41 18.25 31 CC duplicate 88.41 18.08 42-1, 108-112 93 18.9 42CC 95.78 19.01 43-2, 120-125 97 19.1 47-1, 130-133 98.87 17.9 47-1, 130-133 duplicate 98.87 17.8 59-1, 25-28 112 16.56 59-1, 88-94 116 15.81 59-1, 88-94 duplicate 116 15.9 59 CC 120.5 18.7 61-1, 120-125 122.81 19.52 61-1, 120-125 duplicate 122.81 19.17 64-1, 113-118 126.65 20.01 66-1, 125-130 129.17 20.12 Leg 123, Site 766A, 19º 55 S, 110º 27 E, 3997 m Core – Section, Interval (cm) Age d34S(‰) 10 CC, 3-5 73 19.2 11-2, 106-108 75.33 19.4 13-1, 18-20 78.4 18.95 13-2, 106-108 83 18.24 13-3, 74-76 83.9 18.1 14-1, 51-53 85.6 18.34 14-2, 138-142 91 18.55 14 CC, 5-7 93.5 19.04 15-2, 96-98 95 19.22 15-3, 59-61 97 18.51 16-4, 121-123 100 16.32 18-1, 34-39 104 15.64 18-1, 34-39 duplicate 104 15.57 18-4, 112-116 107 15.65 19-1, 31-36 108 15.92 19-4, 113-115 109 16.05 20-3, 98-10 110 15.92 20 CC 111.1 16.09 21-1, 22-26 111.9 16.14 22-1, 27-33 112 16.04 24-1, 12-17 116.3 15.34 24-1, 12-17 duplicate 116.5 15.49 24-1, 110-113 116.5 15.52 26-1, 4-8 119.6 15.54 27-1, 40-44 120 17.23 27-2, 97-10 120.7 17.83 28-2, 112-115 125 19.7 Leg 80, Site 551, 134º 91º N, 13º 30 W, 3887 m Core – Section, Interval (cm) Age d34S(‰) 5-1, 145-148 93.4 19.1 5-2, 91-94 93.6 18.84 5 CC, 1-4 93.8 19.02 Leg 170, Site 1049C, 139º 72 N, 76º 06 W, 2670 m Core – Section, Interval (cm) Age d34S(‰) 12-1, 42-44 111.5 16.33 12-2, 127-129 112 16.29 12-3, 100-102 112.7 16.26 Leg 51, Site 417D, 25º 06 N, 68º 02 W, 5482 m Core – Section, Interval (cm) Age d34S(‰) 21-2, 110-113 119.8 16.4 Leg 51, Site 418B, 25º 02 N, 68º 03 W, 5514 m Core – Section, Interval (cm) Age d34S(‰) 30-2, 112-115 113.1 15.35 Leg 123, Site 765C, 15º 58 S, 117º 34 E, 5728 m Core – Section, Interval (cm) Age d34S(‰) 38-3, 24-28 115.97 15.5 Leg 86, Site 577, 32º 26 N, 157º 43 E, 2675 m Core – Section, Interval (cm) Age d34S(‰) 13-1, 110-113 65.531 19.11