Rhenium and osmium concentrations and osmium isotopic ratios of group IIA, IIIA, IVA, and IVB iron meteorites were determined by negative thermal ionization mass spectrometry with modified digestion and equilibration techniques. Precise isochrons are defined for all four groups. An absolute age of 4558 million years is assumed for group IIIA irons, leading to closure ages of 4537 ± 8, 4456 ± 25, and 4527 ± 29 million years for the group IIA, IVA, and IVB irons, respectively. The initial osmium-187/osmium-188 ratios of the IIA, IIIA, and IVA groups, as a function of crystallization age, suggest that the rhenium/osmium ratio of the parental materials to these asteroidal cores was similar to that of ordinary chondrites. Data for IVB irons, in contrast, indicate a different mode of formation and derivation from a distinctly nonchondritic osmium reservoir.

https://science.sciencemag.org/content/sci/271/5252/1099.full.pdf

Re-Os Ages of Group IIA, IIIA, IVA, and IVB Iron Meteorites

The composition of the primitive mantle derived here shows that Earth was assembled from material that shows many of the same chemical fractionation processes as chondritic meteorites. These processes occurred at the initial stage of the solar system formation, under conditions thought to be present in the solar nebula. But the stable isotope record excludes chondritic meteorites as the ‘building blocks’ of Earth. Meteorites formed in local environments separated from that part of the inner solar system where much of the material forming the terrestrial planets was sourced.

https://booksite.elsevier.com/brochures/treatiseongeochemistry/contents/sample2.pdf

Cosmochemical Estimates of Mantle Composition

Results by Neukum et al. (2001) and Ivanov (2001) are combined with crater counts to estimate ages of Martian surfaces. These results are combined with studies of Martian meteorites (Nyquist et al., 2001) to establish a rough chronology of Martian history. High crater densities in some areas, together with the existence of a 4.5 Gyr rock from Mars (ALH84001), which was weathered at about 4.0 Gyr, affirm that some of the oldest surfaces involve primordial crustal materials, degraded by various processes including megaregolith formation and cementing of debris. Small craters have been lost by these processes, as shown by comparison with Phobos and with the production function, and by crater morphology distributions. Crater loss rates and survival lifetimes are estimated as a measure of average depositional/erosional rate of activity.

/pdf/cratering-chronology-and-the-evolution-of-mars-15gbue0bfh.pdf

Cratering Chronology and the Evolution of Mars

Zolensky ME, and McSween, HY Jr (1988) Aqueous alteration. In Meteorites and the Early Solar System (JF KCITIdge, MS Matthews cds) Univ. of Ari zona, Tucson, 114143 Zoicnsky ME, Score R, Schutt JW, Clayton RN, Mayeda TK (1989a) Lea County 001, an H5 chondrile, and Lea County 002, an ungrouped type 3 chondrite. Meteoritics 24:227-232 Zolensky ME, Barrett R, Prinz M (l989b) Petrography and mineralogy of Yamalo-86720 and Belgica7904. 14th Syrup Ant Meteorites 24-26 Zolensky ME, Barrett R, Prinz M (1989c) Petrography, mineralogy and matrix composition of Yamato82162, a new el2 chondrite (abstr). Lunar Planet Sci XXVL1253-1254 Zolensky ME, Prinz M, Lipschutz ME (199 1) Mineralogy and thermal history of Y-82162, Y-86720, B7904, Abstr Symp Antarct Met 16:195-196 Zolensky ME, Hewins RH , ~ittlefehldt DW, Lindstrom MM, Xiao X, Lipschutz ME (1992) Mineralogy, petrology and geochemistry of carbonaceous chondritie clasts in the LEW 85300 polymiet eucrite. Meteoritics 27:596-604 Zolcnsky ME, Barrett T, Browning L (1993) Mineralogy and composition of matrix and chondrule rims in carbonaceous chondrites. Geochim Cosmochim Acta 57:3123-3148 Zolcnsky ME, Weisb~g MK, Buchanan PC, Mittlcfehldt DW (l996a) Mineralogy of carbonaceous chondrite clasts in HED achondrites and the Moon. Met Planet Sci 31 :518-537 Zol ensky ME, Ivanov AV, Yang V, Mittlefehldt DW, Ohsumi K (l996b) The Kaidun meteorite: Mineralogy of an unusual CM 1 lithology. Meteoritics 31 :484-493 Chapter 4

Non-chondritic meteorites from asteroidal bodies

http://www.geo.arizona.edu/%7Ereiners/Leeetal2009.pdf

Constraints on the depths and temperatures of basaltic magma generation on Earth and other terrestrial planets using new thermobarometers for mafic magmas

Constraints on Martian differentiation processes from RbSr and SmNd isotopic analyses of the basaltic shergottite QUE 94201

Chronology and petrogenesis of young achondrites, Shergotty, Zagami, and ALHA77005 - Late magmatism on a geologically active planet

Crystals of halite and sylvite within the Monahans (1998) H5 chondrite contain aqueous fluid inclusions. The fluids are dominantly sodium chloride-potassium chloride brines, but they also contain divalent cations such as iron, magnesium, or calcium. Two possible origins for the brines are indigenous fluids flowing within the asteroid and exogenous fluids delivered into the asteroid surface from a salt-containing icy object.

https://science.sciencemag.org/content/sci/285/5432/1377.full.pdf

Asteroidal water within fluid inclusion-bearing halite in an H5 chondrite, Monahans (1998)

https://meteoritegallery.com/wp-content/uploads/2014/01/The-age-of-Dar-al-Gani-476-and-the-differentiation-history-of-the-martian-meteorites-inferred-from-their-radiogenic-isotopic-systematics.pdf

The age of Dar al Gani 476 and the differentiation history of the martian meteorites inferred from their radiogenic isotopic systematics

The age of secondary carbonate mineralization in the martian meteorite ALH84001 was determined to be 3.90 +/- 0.04 billion years by rubidium-strontium (Rb-Sr) dating and 4.04 +/- 0.10 billion years by lead-lead (Pb-Pb) dating. The Rb-Sr and Pb-Pb isochrons are defined by leachates of a mixture of high-graded carbonate (visually estimated as approximately 5 percent), whitlockite (trace), and orthopyroxene (approximately 95 percent). 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.

/pdf/the-age-of-the-carbonates-in-martian-meteorite-alh84001-3aihlych1k.pdf

Henry Wiesmann

Papers

Constraints on Martian differentiation processes from RbSr and SmNd isotopic analyses of the basaltic shergottite QUE 94201

Chronology and petrogenesis of young achondrites, Shergotty, Zagami, and ALHA77005 - Late magmatism on a geologically active planet

Asteroidal water within fluid inclusion-bearing halite in an H5 chondrite, Monahans (1998)

The age of Dar al Gani 476 and the differentiation history of the martian meteorites inferred from their radiogenic isotopic systematics

The age of the carbonates in martian meteorite ALH84001.