Using secondary minerals and hydrochemistry to trace geochemical processes in the deep subsurface
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Using secondary minerals and hydrochemistry to trace geochemical processes in the deep subsurface. Henrik Drake Linnaeus University, Sweden

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Using secondary minerals and hydrochemistry to trace geochemical processes in the deep subsurface

Using secondary minerals and hydrochemistry to trace geochemical processes in the deep subsurface

Henrik Drake

Linnaeus University, Sweden

Co-workers: LnU/SKB: Mats Åström, Olga Maskenskaya, Changxun Yu, Frederic Mathurin, Tobias Berger, Linda Alakangas, Birgitta Kalinowski, Ignasi Puigdomenech, Elsewhere: Eva-Lena Tullborg, Johan Hogmalm, Martin Whitehouse, Christine Heim, Magnus Ivarsson, Bill Wallin, Curt Broman, Thomas Zack, etc etc


Billion years of history
Billion years of history geochemical processes in the deep subsurface

Present Groundwaters

Deep Saline Glacial Marine Meteoric

>~500ka 14ka 4-8ka present recharge

Start of mix with brine at 10 Ma

Presently active bacteria

SRB, IRB etc

?

Past activity?

Salinity?

Redox?

Hydrothermal history

Possible Quaternary


Methodology geochemical processes in the deep subsurface

Microscope/SEM

Fluid inclusions

Trace elements

Biomarkers

Geochronology

Fracture orientations

Isotopes

Drake and Tullborg, 2009, AG

Drake et al., in press, AG

Mathurin et al., ES&T (2012)

Drake et al., 2012, GCA

Maskenskaya et al.,

submitted


Hydrothermal
Hydrothermal geochemical processes in the deep subsurface

References:

Drake et al. 2009 Lithos,

Drake and Tullborg, 2009 Appl. Geochem

Drake et al. 2012, GCA, 2013, GCA

Maskenskaya et al., submitted x 2


Hydrothermal1
Hydrothermal geochemical processes in the deep subsurface

Berger et al., 2013

Drake et al., 2013 GCA

Laaksoharju et al., 2009

Mathurin et al., in press GCA


Low temperature minerals
Low temperature minerals geochemical processes in the deep subsurface

  • Recent past conditions (0-10 Ma = minerals, and groundwater 0-0.5 Ma), 0-1000 m

  • Near-surface redox front

  • Fresh/saline interface and

  • Trace element variation/Trace element uptake into calcite

  • Activity of bacteria

    • Sulphate reducers

    • Methanogens

    • Methane oxidation

    • (Iron-reducers)

  • Pre-drilling, undisturbed conditions (minerals)


Redox front
Redox front geochemical processes in the deep subsurface

Can be detected examining redox sensitive minerals and elements


Ce geochemical processes in the deep subsurfaceIII CeIV

Oxides

Drake et al., in prep

Yu et al., in prep

Drake et al., 2009, Appl.Geochem

Drake et al., 2009 Appl.Geochem


Low temperature calcite and pyrite
Low temperature calcite and pyrite geochemical processes in the deep subsurface


TRACE METAL INCORPORATION (CALCITE) geochemical processes in the deep subsurface

Drake et al., (2012, GCA)

Maskenskaya et al., submitted

Also fracture-zone scale variability

Drake et al., (2013, Appl. Geochem.)


Sulphur isotopes in pyrite srb related
Sulphur isotopes in pyrite (SRB-related) geochemical processes in the deep subsurface


This study geochemical processes in the deep subsurface

Drake et al., 2013, GCA

Samples:

Groundwater

(δ34S, SO4, DOC, HCO3)

Pyrite (δ34S)

0 - >900 m depth

Mathurin et al., (2012)


Pyrite
Pyrite geochemical processes in the deep subsurface

  • huge variations across individual crystals (-32 to +73‰)

  • extreme minimum (-50‰) and

  • maximum (+91‰) values.

  • =>141‰ range!

  • SRB activity at all depths analysed, 0-900 m

  • intra-crystal δ34S pattern

  • Increase with growth

Drake et al., 2013, GCA


34 s rim 34 s centre vs so 4
δ geochemical processes in the deep subsurface34Srim- δ34Scentre vs.SO4

Drake et al., 2013, GCA


Ongoing future studies 1 traces of methane oxidation methanogenesis drake et al in prep
ONGOING/FUTURE STUDIES: geochemical processes in the deep subsurface1. TRACES OF METHANE-OXIDATION/METHANOGENESISDrake et al., in prep


Calcite ( geochemical processes in the deep subsurfaceδ13C, δ18O)

0 - >900 m depth

Drake et al.,in press

Appl. Geochem

SIMS10 µm in situ analysis

+ToF-SIMS/GC-MS


Methanogenesis geochemical processes in the deep subsurface

(up to c. +5 per mil)

Small organic influence

Min: -125‰

Influence of organic C, e.g. from plants

Anaerobic oxidation

of methane

(biomarkers are SRB-

specific of high AOM-specificity, ToF-SIMS+GC/MS data)

Drake et al., in prep


Methanogenesis geochemical processes in the deep subsurface

(up to c. +5 per mil)

Min: -125‰

Drake et al., in prep


Similar study from forsmark
Similar study from Forsmark geochemical processes in the deep subsurface

Methanogenesis

(to +12 per mil)

Anaerobic oxidation

of methane


Stable isotope variation and trace element uptake in recent 17y precipitates at sp
Stable isotope variation and trace element uptake geochemical processes in the deep subsurfacein recent, <17y, precipitates at Äspö

  • Micro-variation of sulphur isotopes in pyrite

  • Trace element uptake in calcite


PRECIPITATES ON BOREHOLE EQUIPMENT AT ÄSPÖ (-450 m) geochemical processes in the deep subsurface

Mathurin et al., ES&T (2012)

Drake et al., in prep


MICRO-SCALE S-ISOTOPE VARIATION geochemical processes in the deep subsurface

δ34Ssulphate +18 to +28‰

δ34Ssulphide -29 to -1‰

Iron isotopes to be added,

First SIMS results of fracture-

coating pyrite δ56Fe -0.9 to +2.8‰

Drake et al., in review


TRACE METAL INCORPORATION INTO CALCITE geochemical processes in the deep subsurface

+Ba, LREEs

(+Y, V)

(not shown)

Drake et al., in prep


Stable isotope variation in calcite
STABLE ISOTOPE VARIATION IN CALCITE geochemical processes in the deep subsurface

Drake et al., in review


Finally this area has
Finally, geochemical processes in the deep subsurfacethis area has

  • Most depleted δ13Ccalcite reported (-125‰)

  • Largest δ13Ccalcite range within a single crystal (109‰)

  • Largest range of δ13Ccalcite from single location (129‰)

  • Largest δ34Spyrite range from single location (141‰; Drake et al., 2013, GCA)

  • Thank you!

δ34S

δ13C


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