Abstract
Abstract The ∼4500-m-deep Iceland Deep Drilling Project (IDDP) borehole IDDP-2 in Iceland penetrated the root of an active seawater-recharged hydrothermal system below the Mid-Atlantic Ridge. As direct sampling of pristine free fluid was impossible, we used fluid inclusions to constrain the in situ conditions and fluid composition at the bottom of the hydrothermal convection cell. The fluid temperature is ∼600 °C, and its pressure is near-hydrostatic (∼45 MPa). The fluid exists as two separate phases: an H2O-rich vapor (with an enthalpy of ∼59.4 kJ/mol) and an Fe-K–rich brine containing 2000 µg/g Cu, 3.5 µg/g Ag, 1.4 µg/g U, and 0.14 µg/g Au. Occasionally, the fluid inclusions coexist with rhyolite melt inclusions. These findings indicate that the borehole intersected high-energy steam, which is valuable for energy production, and discovered a potentially ore-forming brine. We suggest that similar fluids circulate deep beneath mid-ocean ridges worldwide and form volcanogenic massive sulfide Cu-Zn-Au-Ag ore deposits.
Highlights
AND GEOLOGICAL BACKGROUNDThe Iceland Deep Drilling Project (IDDP) explores the economic potential of geothermal fluids in the deep roots of active geothermal systems (Friðleifsson et al, 2020)
The ∼4500-m-deep Iceland Deep Drilling Project (IDDP) borehole IDDP-2 in Iceland penetrated the root of an active seawater-recharged hydrothermal system below the M id-Atlantic Ridge
We suggest that similar fluids circulate deep beneath mid-ocean ridges worldwide and form volcanogenic massive sulfide Cu-Zn-Au-Ag ore deposits
Summary
The Iceland Deep Drilling Project (IDDP) explores the economic potential of geothermal fluids in the deep roots of active geothermal systems (Friðleifsson et al, 2020). This includes evaluation of the feasibility of exploiting supercritical fluid for energy production and/ or extracting economically valuable elements directly from this fluid (e.g., Maimoni, 1982; McKibben and Elders, 1985). The major-element composition of geothermal fluid recovered from shallower depths (
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
