Presentation is loading. Please wait.

Presentation is loading. Please wait.

Particulate trace metals Phoebe Lam Marine Bioinorganic Chemistry lecture November 22, 2011.

Published byWendy Armstrong Modified over 8 years ago

Similar presentations

Presentation on theme: "Particulate trace metals Phoebe Lam Marine Bioinorganic Chemistry lecture November 22, 2011."— Presentation transcript:

1 Particulate trace metals Phoebe Lam Marine Bioinorganic Chemistry lecture November 22, 2011

2 outline Why are particles important How do we sample for particulate trace metals (suspended, sinking) Techniques for analysis Sample profiles (bulk) Sample profiles (speciation)

3 Why are particles important to trace metal (TM) cycling? Source of lithogenic TMs (dust, mobilization of continental margin and benthic sediments) Participate in internal cycling of TMs: release some TMs into solution, provide surfaces for scavenging TMs out of solution; biological uptake and remineralization Are the ultimate sink of dissolved trace metals (vertical particle export and removal to sediments)

4 Sampling for suspended particles McLane battery- operated in-situ pump: <1000L, size fractionated MULVFS: Multiple Unit Large Volume in-situ Filtration System (ship power): <12,000L, 3 flow paths, size fractionated (Jim Bishop) GO-Flo filtration: 10L, size fractions hard Gas line to over- pressure 47mm or 25mm filter holder goes here 142mm filter holders 142mm 293mm 47mm

5 Sampling for sinking particles PIT-style surface-tethered sediment trap, adapted for trace metal clean collection (Carl Lamborg) Using 234 Th/ 238 U disequilibrium and particulate 234 Th:TM ratios (Weinstein and Moran 2005)

6 The basic analysis: applying crustal ratios to total digests Total digests using (sub)boiling strong acids with HF to dissolve aluminosilicates Sherrell and Boyle, 1992, after Taylor 1964 GCA

7 Nutrient(-like) dissolved profiles have mirror image particulate profiles Nozaki 2001 Dissolved profiles from N.Pacific Sherrell and Boyle 1992 Particulate profiles, BATS

8 Al, Fe: The “Major minors (nM)” Dissolved Al, Fe from BATS in 2008 (GEOTRACES IC1, Bruland website) Al Fe Particulate Al, Fe from BATS in 1987 (Sherrell and Boyle, 1992) Dissimilar dissolved profile shapes but similar particulate profile shapes--increase until ~1000m, then constant until nepheloid layer at bottom Strong nepheloid layers with concentrations 7x higher than water column profile

9 Mn, Co, Pb, Zn, Cu, Ni: the “Minor minors (pM)” (Sherrell and Boyle, 1992) At BATS, similar profiles: Generally low at the surface, increasing to max at 500m Authigenic Mn as host phase for scavenged metals? (not everywhere, see next slide) Nepheloid layers in most pTMs (Mn, Co, Zn, Ni), but not Pb, Cu, and not nearly as strong as for Fe, Al Mn CoPbZnCuNi

10 Mn, Co, (Pb,) Zn, Cu, Ni: the “Minor minors (pM)” Ohnemus et al. unpublished GEOTRACES data Off NW Africa, “minor minors” group differently: pMn and pCu min at surface, subsurface max (more like lithogenic) pCo, pZn, pNi max at surface (biogenic)

11 Lithogenic Tracers Bulk comparisons within the data Ohnemus et al. unpublished GEOTRACES data

12 Lithogenic contribution to pTMs (Sherrell and Boyle, 1992) % particulate Al: <10% Fe: ~50% Mn: <25% Co: <10% Zn: <5% Cu: <5% Ni: <5% Cd: <5% Pb: <5% Lithogenics are strong sources for Al, Fe everywhere, moderate for Mn and Co, not at all for Zn, Cu, Ni (?), Cd, Pb Fe has the highest %particulate

13 Motivation for size-fractionation: Particle dynamics (via geochemistry, USGT NAZT stn 11) 0 200 400 600 0 200 400 600 Depth (m) Part. PhosphorusPart. Barium Production of 1-51um P by photosynthesis near surface >51um P near surface from aggregate formation μm-sized barite particles formed in micro- environments of aggregates near surface  max in >51um Ba near surface As organic matter remineralizes (gradient in P), aggregates fragment and release barite into small size fraction Maximum in remineralization in P coincides with max in 1- 51um Ba Suspended (1- 51um) size fraction Sinking(>51u m) size fraction Unpublished US GT NAZT data from Dan Ohnemus

14 Modelling scavenging and removal (I) Small suspended particles Large fast- sinking particles Remineralization (biogenic particles only) Aggregation/repa ckaging disaggregation “Activity” on large particles “Activity” on small particles Dissolved “activity” adsorption desorption remineralization Aggregation/repa ckaging disaggregation sinking Marchal and Lam, submitted; after Murnane et al. 1990

15 Modelling scavenging and removal (II) (Sherrell and Boyle, 1992) Use slope of particulate 230 Th profile to estimate the mean particle sinking speed, S; Residence time, τ p =D/S F T =F S +F R F R =(Me P *D)/τ p = Me P *S How much of total flux (F T ) is due to sinking from the surface (F S ) vs. repacking (F R ) in the water column? D Suspended particle residence time

16 Modelling scavenging and removal (III) (Sherrell and Boyle, 1992) -repackaging flux (F R ) provides ~30% of total flux out of surface (except Cd: 80%, Zn: 10%); i.e. Most of total flux due to flux out of surface (F S )

17 Pools of particulate trace metals Biological Surface adsorbed Authigenic particles Lithogenic particles

18 Simplified Fe cycle Terrigenous (clays (dust), oceanic crustal material, volcanic sediments) Biota Atmospheric deposition Dissolved (Fe-L) Lateral transport (from rivers, continental margin) Authigenic (hydroxides) Uptake/scavenging Sinking Dissolved Pool Particulate Pool Remineral- ization

19 How to distinguish between different pools?? Leaching methods (not exhaustive!): “biogenic”: weak acid+mild reductant+heat (Berger et al. 2007); total-lithogenic (Frew et al. 2006) “surface adsorbed”: oxalate wash (Tovar-Sanchez et al. 2004) “authigenic”: mild reductant+acid (eg. Poulton and Canfield 2005) “lithogenic”: strong acid digest (w/ HF) and crustal Al:TM ratio (eg. Sherrell and Boyle 1992; Frew et al. 2006) Biological Surface adsorbed Authigenic particles Lithogenic particles

20 X-Ray Fluorescence (XRF) microprobe: spatial distribution of elements Incident x-rays Sample Detector Fluor- escent x-rays Wikipedia Incident beam of 10keV

21 Synchrotron X-Ray microprobe: spatial distribution of pTM 71m 1 mm Red=Fe Blue=Ca Lam et al. GBC 2006 Silicoflagellate (scale bar = 20 um) c/o Ben Twining Cellular scaleAggregate scale

22 Speciation from X-Ray Absorption Spectroscopy: valence EXAFS region Energy (eV) Absorption XANES region Position of edge depends on valence Energy (eV) Absorption Fe

23 Speciation from X-Ray Absorption Spectroscopy: mineralogy Fe EXAFS region Energy (eV) Absorption XANES region Clay Olivine Hydroxide Organic Fe

24 Chemical species mapping combines μXRF and XAS 7105eV 7117eV 7124eV7180eV 7105eV: background defined for all species 7117eV: pyrite (iron sulfide) has a distinct shoulder and is significantly higher than biotite (Fe(II)-silicate) or Ferrihydrite-2L (Fe(III)) 7124eV: Fe(III) is significantly lower than Fe(II) or pyrite 7180eV: all species are equal 7105eV 7117eV7124eV7180eV Lam et al. GCA, in revision

25 Northwest Pacific, Stn K2 550km from coast Eastern Tropical Atlantic Stn 3 550km from coast Fe(II) is much more important in the NW Pac Fe(III) is much more important in the E. Atl Total pFe Fe(III) Fe(II) Pyrite Acid-leachable pFe Total pFe Fe(III) Fe(II) Pyrite Acid-leachable pFe Lam et al. GCA, in revision

26 Chemical maps of potential endmembers Mauritanian sediments 39%pyrite, 20%Fe(II), 41%Fe(III) Saharan Dust 1%pyrite, 14%Fe(II), 85%Fe(III) Pyrite is a unique tracer of sedimentary source of Fe Lam et al. GCA, in revision

27 References

Download ppt "Particulate trace metals Phoebe Lam Marine Bioinorganic Chemistry lecture November 22, 2011."

Similar presentations

North Patch South Patch 1 28 3 4567 SAMPLE COLLECTION & ANALYSIS We deployed the Multiple Unit Large Volume in-situ Filtration System (MULVFS) during the.

North Patch South Patch SAMPLE COLLECTION & ANALYSIS We deployed the Multiple Unit Large Volume in-situ Filtration System (MULVFS) during the.
1 Carbon Cycle 9 Carbon cycle is critically important to climate because it regulates the amount of CO 2 and CH 4 in the atmosphere. Carbon, like water,

1 Carbon Cycle 9 Carbon cycle is critically important to climate because it regulates the amount of CO 2 and CH 4 in the atmosphere. Carbon, like water,
Concentartion of metals in the rivers of south part of Primorie, Russia. V. M. Shulkin, N. N. Bogdanova Pacific Geographical Institute RAS, Vladivostok.

Concentartion of metals in the rivers of south part of Primorie, Russia. V. M. Shulkin, N. N. Bogdanova Pacific Geographical Institute RAS, Vladivostok.
Particulate organic matter and ballast fluxes measured using Time-Series and Settling Velocity sediment traps in the northwestern Mediterranean Sea lead.

Particulate organic matter and ballast fluxes measured using Time-Series and Settling Velocity sediment traps in the northwestern Mediterranean Sea lead.
Lecture 3 Trace Elements in Seawater What are trace elements? Why are they important? Principal of Oceanographic Consistency. Profiles shapes as clues.

Lecture 3 Trace Elements in Seawater What are trace elements? Why are they important? Principal of Oceanographic Consistency. Profiles shapes as clues.
1 Nitrogen Cycle Most of Nitrogen is in the atmosphere. 14 N = 99.6% 15 N = 0.4% Air is standard for  15 N Range is –20 to +20 ‰

1 Nitrogen Cycle Most of Nitrogen is in the atmosphere. 14 N = 99.6% 15 N = 0.4% Air is standard for  15 N Range is –20 to +20 ‰
Abstract As part of the VERTIGO project (VERtical Transport In the Global Ocean) we used Thorium-234 ( 234 Th) as a natural proxy for particle export.

Abstract As part of the VERTIGO project (VERtical Transport In the Global Ocean) we used Thorium-234 ( 234 Th) as a natural proxy for particle export.
Metal concentrations in groundwater around disturbed and undisturbed massive sulfide deposits H. Pauwels, A. Lassin, J.C. Foucher,Y. Deschamps, M. L. Tercier-Waeber,

Metal concentrations in groundwater around disturbed and undisturbed massive sulfide deposits H. Pauwels, A. Lassin, J.C. Foucher,Y. Deschamps, M. L. Tercier-Waeber,
Rosie Chance, Alex Baker, Tim Jickells, Alina Marca

Rosie Chance, Alex Baker, Tim Jickells, Alina Marca
12.710 Intoduction to Marine Geology and Geophysics 11/1 Mid Term Sediments, Processes, and the Sedimentary Record 11/6 (McManus) Deep-sea sediments: composition,

Intoduction to Marine Geology and Geophysics 11/1 Mid Term Sediments, Processes, and the Sedimentary Record 11/6 (McManus) Deep-sea sediments: composition,
Nutrient dynamics in the deep blue sea – David M. Karl

Nutrient dynamics in the deep blue sea – David M. Karl
Lecture 10: Ocean Carbonate Chemistry: Ocean Distributions Controls on Distributions What is the distribution of CO 2 added to the ocean? See Section 4.4.

Lecture 10: Ocean Carbonate Chemistry: Ocean Distributions Controls on Distributions What is the distribution of CO 2 added to the ocean? See Section 4.4.
OCN520 Fall 2009 Mid-Term #2 Review Since Mid-Term #1 Ocean Carbonate Distributions Ocean Acidification Stable Isotopes Radioactive Isotopes Nutrients.

OCN520 Fall 2009 Mid-Term #2 Review Since Mid-Term #1 Ocean Carbonate Distributions Ocean Acidification Stable Isotopes Radioactive Isotopes Nutrients.
GeoSoilEnviroCARS 2002-02-28 Matt Newville, Steve Sutton, Mark Rivers Applications: XANES EXAFS Techniques: Near-neighbor distances and coordination environment.

GeoSoilEnviroCARS Matt Newville, Steve Sutton, Mark Rivers Applications: XANES EXAFS Techniques: Near-neighbor distances and coordination environment.
Particulate scavenging and lateral transport processes in the Kaoping River-Sea System based on 210 Po and 210 Pb distributions and disequilibrium Hung.

Particulate scavenging and lateral transport processes in the Kaoping River-Sea System based on 210 Po and 210 Pb distributions and disequilibrium Hung.
Trace Metals & Phytoplankton Gert Vlaming 24-01-2003.

Trace Metals & Phytoplankton Gert Vlaming
Information from stream sediments Measurement of concentration of metals present (as solids) in sediment Gives information on: 1.Background levels of contamination.

Information from stream sediments Measurement of concentration of metals present (as solids) in sediment Gives information on: 1.Background levels of contamination.
Lecture 3 Trace Metals in Seawater What are trace elements? Why are they important? Principal of Oceanographic Consistency. Profiles shapes as clues for.

Lecture 3 Trace Metals in Seawater What are trace elements? Why are they important? Principal of Oceanographic Consistency. Profiles shapes as clues for.
Cycling of Ocean Micronutrients: What do we Know and What do we Need to Know? Ed Boyle Earth, Atmospheric and Planetary Sciences Massachusetts Institute.

Cycling of Ocean Micronutrients: What do we Know and What do we Need to Know? Ed Boyle Earth, Atmospheric and Planetary Sciences Massachusetts Institute.
Paper Number OS 26A-06 At both sites, the majority of the vertical flux attenuation of components such as carbon occurred with the mesopelagic “Twilight.

Paper Number OS 26A-06 At both sites, the majority of the vertical flux attenuation of components such as carbon occurred with the mesopelagic “Twilight.

Similar presentations

Ads by Google