1. BIODEEP WP 2 Chemical characterization of seawater/brine/ sediments and related fluxes. A. watercolumn/brine analyses (UU) A. watercolumn/brine analyses (UU) B. susp.mat. major/minor elements; C,N (UU) B. susp.mat. major/minor elements; C,N (UU) key trace elements (Pb,Co,Zn,Cu,Cd) (UP) key trace elements (Pb,Co,Zn,Cu,Cd) (UP) C. sed.traps major/minor elements; C,N (UU) C. sed.traps major/minor elements; C,N (UU) microfossils / biogenic components (UM) microfossils / biogenic components (UM) radiotracers ( 210 Pb, 230 Th) (SOC) radiotracers ( 210 Pb, 230 Th) (SOC) D. sediments (major/minor elements; C,N) (SOC/UU) D. sediments (major/minor elements; C,N) (SOC/UU) key trace elements (Pb,Co,Cu,Zn,Cd) (UP) key trace elements (Pb,Co,Cu,Zn,Cd) (UP) E. pore water extraction/analysis (UU) E. pore water extraction/analysis (UU) WP2.1 CRETE- yr2

2. Aspects related to brine redox chemistry o N-species o S-species o Mn 2+ - MnO 2 cycling o Fe 2+ - Fe 2 O 3 - Fe,S cycling o SO 4 2 - - HS - cycling

3. N-species At interface seawater/brine: nitrate jumps from 5 to 0 uM, whereas ammonia goes from ~ 0.2 to 3600 uM In oxic seawater: org.mat. + O 2  106 HCO 3 - + 16 NO 3 - HPO 4 2- In anoxic brine: org.mat. + SO42-  106 HCO3- + 16 NH 4 + HPO 4 2- + 53 HS -

4. S-species: examplified by the most extreme case: URANIA Brine CH 4 + SO 4 2- -  HCO 3 - + HS - + H 2 O Likely dominant reaction in Urania :

5. Atalante Basin phosphate and DIC data (BD10CT); seawater/brine interface oyxgen en sulphide data (UM08CT)

6. WP2-CTD1

7. Bannock brines I/II (BD34CT): density and alkalinity Note rapid increase in alkalinity at seawater/brine I interface, and the rapid decrease at the brine I/II transition

8. Orca/AB interface comparison

9. 2060 2120 2180 2240 2300 2360 2420 Orca/AB- 2

10. Orca/Med.brines Major difference in interface thickness Major difference in interface thickness (~ 100 m vs ~ 100 cm) (~ 100 m vs ~ 100 cm) Major difference in redox-chemistry Major difference in redox-chemistry (Fe, S a.o.; see below) (Fe, S a.o.; see below) Orca relative to Mediterranean brine basins:

11. Manganese cycling: observations in other redox-dominated environment : o Tyro Basin

12. TB Tyro basin, eastern Mediterranean

13. Manganese cycling at seawater/brine Interface : (replotting data De Lange et al.)

14. At interface seawater/brine, Mn2+ concentration jumps from ~ 0.005 to 5 umole/kg, whereas HS- goes from 0.03 to 1800 umole/l BB-Mn/HS

15. Bannock and Orca brines dissolved Fe 2+, HS - (UU, Saager et al.; after Trefry et al.; Wiesenburg et al.) (note different scales !

16. 2004 Mn 2+ (uM) 0.33.000 HS - (uM) 30.00020 Fe 2+ (nM) BannockOrca BBvsOB Fe,S Major importance of: S > Mn > Fe

17. Brines average major elements

18. Interface Brine basin interfaces

19. Interface Conservative behaviour of Ca, Sr, K Diss. Mn and HS- may only be done if sampled and stored properly Bannock basin interface

20. Suspended matter How much material in suspension Composition of material: major and trace elements as well as C and N concentrations Major analytical problems because of very little sample material, and also because of extremely high salt contents of samples, …. Salt corretions are only very rough, so the results are high in error. Samples should be washed just after filtreation to remove the salt, this is vital for a reliable analysis

21. Suspended matter Average suspended material in different basins

22. Suspended matter 1062049143611506210B 774472 33628D B 502650542556112858U B 192976444108170211A B ppm mg/l SrSKCa susp. matter Average total mass and composition Mass and concentrations are corrected for salt influence

23. Suspended matter bdl

24. Sediment traps 3500ST3 2500ST2 1500ST1 Depth (m)Station BD03 Bannock basin

25. Sediment traps 3500ST3 2500ST2 1500ST1 Depth (m)Station BD03 Bannock basin

26. Sediment traps 3500ST3 2500ST2 1500ST1 Depth (m)Station BD03 Bannock basin 3500ST4 2800ST3 1500ST2 460ST1 Depth (m)Station PS 027 Urania basin

27. Sediment traps 3500ST3 2500ST2 1500ST1 Depth (m)Station BD03 Bannock basin 3500ST4 2800ST3 1500ST2 460ST1 Depth (m)Station PS 027 Urania basin

28. Methodology: Total destruction of samples for ICP-OES and ICP-MS analysis Subsampling during total destruction for Si analysis with photospectrometer C-total, C-organic and N contents with CNS- analyser

29. Total mass flux (average september-may)

31. Additional Si input in sediment: evidence for dust input

32. Urania basin oxic Bannock basin oxic 14,73,9 average mass flux (mg/m2/d)

33. 154.4353.71000.936.6134.8 anoxic 1.2 23.90.53.1 oxic Urania basin 24.71.073.03.218.9 anoxic 0.8 3.80.31.0 oxic (mg/m2/d) (µg/m2/d)(mg/m2/d) Bannock basin SiSMnFeCa Average elemental fluxes

34. Average chemical characterization of sediment 56,1Terr. 2,2OM 8,7SiO 2 extra 33,0CaCO 3 Wt%Comp. WP2.1 Bannock anoxic

35. Bannock anoxic 2001/2002

36. Average Si-flux Bannock anoxic

37. Average S-flux Bannock anoxic

38. Average Mn-flux Bannock anoxic

39. Average CaCO 3 -flux Bannock anoxic

40. Average C org -flux Bannock anoxic

41. Average N-flux Bannock anoxic

42. WP2-2 Chemical characterization of sediments & pore waters Chemical characterization of sediments & pore waters

43. WP2.1d BoxcoreSampling site BW sampleWinckler bottles PW extr. Glove- box water% samples BD19MCDBx XYES #1 BD21MCUB.ex XYES #1 BD26BCABx XYES #1 BD27BCnormalxx BD31BCnormalxx BD42BCBBx x YES #1 BIODEEP 2002 pore/water sampling

44. Chemical characterization of sediments Sediment preparation methods (+/- salt removal, prior to analysis; intercalibration,..) Sediment preparation methods (+/- salt removal, prior to analysis; intercalibration,..) Intercalibration (methods, Labs,…) (see Thomson) Intercalibration (methods, Labs,…) (see Thomson) Sediment composition Sediment composition

45. BD26BC (AB)

46. BD26BC (AB) Mg/Al Na/Al

47. BD26BC (AB) Ca/Al Mn/Al

48. BD41BC (BB)

49. BD41BC (BB) Ca/Al Mn/Al

50. UBcores BD07BC BD21MC Major differences occur between the core in E and W basin

51. BD21MC (UB east)

52. BD21MC (UB-east) porewater results Brine ?! Precip. ?!

53. BD21MC (UB-east) solid phase results

54. BD07BC (UB-west) sediment results

55. Clearly for some elements the total sediment is salt- dominated Clearly for some elements the total sediment is salt- dominated Corrections can be done from intercalibration results Corrections can be done from intercalibration results

56. UR2001 sed. Sediment composition (DB)

57. Sediment composition (DB)

58. BD19MC-Cl BD19MC (DB)

59. WP2.1e BD19MC BW

60. DB-sediment BD19MC porewater results

61. BD19MC

62. DBalls

63. Prelim. Composition: Ca 6 Mg 20 (SO 4 ) 6 Cl 13 (CO 3 2- ) x. y H 2 O

64. Future Perspectives Suspended matter (esp. at interfaces) Suspended matter (esp. at interfaces) Gas content of brines (pressure sampling!) Gas content of brines (pressure sampling!) Sediment traps Sediment traps Sediment work (Discovery basin) Sediment work (Discovery basin)