Petrographic Thin-Section & SIMS Probe
Early Noachian Pre-Tharsis Crust
90°
Martian Meteorite Catalog
Discovery Insight: 4.476 Ga zircon clasts within NWA 7034 preserve primary mantle-crust differentiation. Hydrothermal alteration veins at 4.12 Ga exhibit an elevated D/H enrichment ratio (3.2× SMOW), confirming rapid planetary water inventory escape occurred during the pre-Noachian to Early Noachian transition.
SIMS Isotopic & Hydrothermal Telemetry
Microprobe Precision: ±14 Ma
Zircon U-Pb Age
4.476 Ga
²⁰⁶Pb/²³⁸U Crystallization
Alteration Age
4.120 Ga
Hydrothermal Matrix Veins
D/H Isotopic Ratio (δD)
3.20 × SMOW
Heavy Isotope Fractionation
Hydrothermal Temp
235 °C
Hydrous Apatite-Oxide Equil.
Planetary Atmospheric Escape & Hydrosphere Budget
Global Ocean Eq: 140.5 m
Atmospheric Escape Rate
2.40 kg/s
Hydrodynamic & Solar Stripping
Water Loss Fraction
58.0%
Depleted by 4.12 Ga Alteration
Isotopic Fractionation Ledger
| Target Clast | Lithology | U-Pb (Ga) | δD (SMOW) | Status |
|---|