A Younger Age for ALH84001 and Its Geochemical Link to Shergottite Sources in Mars

  title={A Younger Age for ALH84001 and Its Geochemical Link to Shergottite Sources in Mars},
  author={T. J. Lapen and Minako Righter and A. D. Brandon and Vinciane Debaille and Brian L. Beard and John T. Shafer and Anne H. Peslier},
  pages={347 - 351}
Less Old Martian Meteorite The oldest Martian meteorite known, ALH84001, was thought to be a remnant of primordial martian crust formed during solidification of an early magma ocean. Using isotope data, Lapen et al. (p. 347) revised the crystallization age of this meteorite from 4.51 billion years to 4.09 billion years ago, meaning that this rock cannot be a fragment of primordial crust that escaped the period of intense bombardment that occurred between 4.25 and 4.10 billion years ago. The… Expand
Core Formation and Mantle Differentiation on Mars
Geochemical investigation of Martian meteorites (SNC meteorites) yields important constraints on the chemical and geodynamical evolution of Mars. These samples may not be representative of the wholeExpand
The Source Crater of Martian Shergottite Meteorites
It is shown that the <5 million-year-old and 55km-wide Mojave Crater on Mars is the ejection source for the meteorites classified as shergottites, and the cratering-based age determination method for Mars is now calibrated in situ, and it shifts the absolute age of the oldest terrains on Mars backward by 200 million years. Expand
Two billion years of magmatism recorded from a single Mars meteorite ejection site
The spatial association of 327- to 2403-Ma depleted shergottites indicates >2 billion years of magmatism from a long-lived and geochemically distinct volcanic center near the ejection site. Expand
Solving the Martian meteorite age conundrum using micro-baddeleyite and launch-generated zircon
The presence of ancient, non-convecting mantle beneath young volcanic Mars is confirmed, an upper bound on the interplanetary travel time of the ejected Martian crust is placed, and a new approach to the geochronology of the inner Solar System is validated. Expand
Geochemistry of Martian basalts with constraints on magma genesis
Abstract Over the past decade, our knowledge of the geochemical and mineralogical diversity of Martian rocks has greatly increased. Rocks on the surface of Mars are older than most Martian meteoritesExpand
Combining meteorites and missions to explore Mars
The history inferred from martian meteorites conflicts with results from recent Mars missions, calling into doubt whether the igneous histor y inferred from the meteorites is applicable to Mars as a whole. Expand
Carbonate formation events in ALH 84001 trace the evolution of the Martian atmosphere
The results indicate the presence of a Ca-rich carbonate phase enriched in 18O that formed sometime after the primary aqueous event at 3.9 Ga, indicating that the Noachian atmosphere of Mars was substantially depleted in 13C compared with the modern atmosphere. Expand
The internal structure and geodynamics of Mars inferred from a 4.2-Gyr zircon record
The results imply that zircon is ubiquitous on the Martian surface, providing a faithful record of the planet’s magmatic history. Expand
Pre-4.0 billion year weathering on Mars constrained by Rb–Sr geochronology on meteorite ALH84001
Abstract The timing and nature of aqueous alteration of meteorite ALH84001 has important implications for the history of water on early Mars, the evolution of the Martian atmosphere, and theExpand
Uranium‐lead age of baddeleyite in shergottite Roberts Massif 04261: Implications for magmatic activity on Mars
[1] The issue of the duration of Martian magmatic activity is one of the controversial debates recently: whether the young radiometric ages of ∼180 Ma for shergottites, a class of Martian meteorites,Expand


Records of an ancient Martian magnetic field in ALH84001
Although Mars does not presently appear to have a global dynamo magnetic field, strong crustal fields have recently been detected by the Mars Global Surveyor above surfaces formed ∼3 or more Ga. WeExpand
Ages and Geologic Histories of Martian Meteorites
We review the radiometric ages of the 16 currently known Martian meteorites, classified as 11 shergottites (8 basaltic and 3 lherzolitic), 3 nakhlites (clinopyroxenites), Chassigny (a dunite), andExpand
Martian meteorite chronology and the evolution of the interior of Mars
Abstract The Earth, Moon, and Mars are the only three planets for which satellite and ground observations can be confronted with extensive chronological and geochemical observations of rock samples.Expand
Ar-Ar chronology of the Martian meteorite ALH84001: evidence for the timing of the early bombardment of Mars.
The experiments provide the first evidence of an event occurring on Mars coincident with the time of the late heavy bombardment of the Moon and may reflect a similar period of bombardment in the Southern Highlands of Mars. Expand
A petrogenetic model for the origin and compositional variation of the martian basaltic meteorites
The major element, trace element, and isotopic compositional ranges of the martian basaltic meteorite source regions have been modeled assuming that planetary differentiation resulted fromExpand
Rapid decrease in Martian crustal magnetization in the Noachian era: Implications for the dynamo and climate of early Mars
[1] The magnetic signatures and crater retention ages of the 19 largest (>1000 km diameter) impact basins on Mars are examined to constrain the history of the acquisition of crustal magnetizationExpand
The age of the carbonates in martian meteorite ALH84001.
The carbonate formation age is contemporaneous with a period in martian history when the surface is thought to have had flowing water, but also was undergoing heavy bombardment by meteorites, therefore, this age does not distinguish between aqueous and impact origins for the carbonates. Expand
The Lu–Hf isotope geochemistry of shergottites and the evolution of the Martian mantle–crust system
We report the first Lu‐Hf isotopic data from SNC (Martian) meteorites with high-precision analyses of five shergottites by plasma sector mass spectrometry. Hf isotopic compositions indicate theExpand
The history of Allan Hills 84001 revised: multiple shock events.
  • A. Treiman
  • Geology, Medicine
  • Meteoritics & planetary science
  • 1998
The geologic history of Martian meteorite Allan Hills (ALH) 84001 is more complex than previously recognized, with evidence for four or five crater-forming impacts onto Mars. This history of repeatedExpand
Origins of magnetite nanocrystals in Martian meteorite ALH84001
Abstract The Martian meteorite ALH84001 preserves evidence of interaction with aqueous fluids while on Mars in the form of microscopic carbonate disks. These carbonate disks are believed to haveExpand