Adsorption on hydrothermal chimneys

Task 6 – Adsorption and condensation on hydrothermal chimneys

Task leader Isabelle Daniel & Muriel Andreani
Participants LGL LRS PhENIx LIEC JHU

Objectives

  • Evaluation of biomolecule condensation reactions and adsorption on representative hydrothermal chimneys sampled at vent fields corresponding to type 1 (Lucky Strike, 37°N), type 2 (Rainbow, 36°N) and type 3 (Lost City, 30°N) hydrothermal systems along the Mid-Atlantic Ridge:
    • at ambient pressure,
    • under the pressure corresponding to their original depth, under a common high-pressure of 50 MPa for comparison.
  • Identifying the type of hydrothermal system, which is the most suitable to condensation, adsorption and polymerization of biomolecules
  • Recognizing the series of minerals that control condensation, adsorption and polymerisation of biomolecules.

Description of work

  • Detailed characterization of chimney mineralogy
  • Measurement of adsorption isotherms
  • Characterization of adsorbed biomolecules and mineral surfaces after hydrothermal reaction (microRaman and micro-IR spectroscopies, XPS, NAP-XPS, AFM, STXM, synchrotron XRD)
  • Desorption of biomolecules, identification in solution by MALDI-TOF analysis

Role of participants

M. Andreani: selection, characterization and preparation of the hydrothermal chimneys. Their availability will be facilitated by her involvement in many international (IODP) and national oceanographic cruises.
I. Daniel: design of the experiments and adsorption experiments
U. Pedreira-Segade: adsorption of selected nucleotides and aminoacids on Lost City- and Rainbow-type hydrothermal chimneys associated with serpentinization of ultramafic basement
Postdoctoral fellow: adsorption of selected nucleotides and aminoacids on Lucky strike type hydrothermal chimneys in mafic (basaltic) high-temperature venting systems.

Risks and contingency plan

Extremely limited

  • The experimental risk has already been assessed in task 4
  • The most famous samples might not be ultimately available, such as the Lost City ones. However, M. Andreani has been on many IODP cruises and is qualified to request and recognize closely related samples, such as the structures produced at low-temperature in ophiolites.

Deliverables / milestones

D6.1 – biomolecule adsorption isotherms on hydrothermal chimneys at ambient pressure
D6.2 – biomolecule adsorption isotherms on the hydrothermal chimneys under hydrothermal conditions
D6.3 – the mineral and/or type of hydrothermal system that played a key role in the origin of life
M6.1 – collection of chimney samples (m12)
M6.2 – adsorption isotherms at ambient conditions (m24)
M6.3 – adsorption isotherms under hydrothermal conditions (m36)
M6.4 – Comparison of the results: role of thermodynamic conditions, role of the different minerals and hydrothermal settings (m42)