The Open University's repository of research publications and other research outputs Solar noble bases in enstatite chondrites and implications for the formation of the terrestrial planets Conference Item

EH6 Chondrites: The two principal groups of en-statite chondrites differ in their proportions of petro-logic types. Among EL chondrites, ~20% are type 3 and ~60% are type 6, whereas among EH chondrites, ~75% are type 3 and ~3% are type 6. As of this writing , there are five EH6 chondrites listed in the Meteor-itical Bulletin Database (MBD): A-882039, Y-793225 (EH6-an), Y-8404, Y-980211 and Y-98...

All ten known aubrites (enstatite achondrites) as well as Happy Canyon and Mt. Egerton, related anomalous meteorites, have been studied in order to understand their origin and relationship to enstatite chondrites. Mineralogically, aubrites contain 75-9B% enstatite (En98.76-99.54), 1-16% plagioclase (Anl.S-B.:), O.Z-K.l^r diopside (Wo40.1-46.1). 0.3-10.07f olivine (Fo99.79-99,99), <0.l3.7% metal...

OH-defects in orthoenstatite were studied experimentally between 4 and 8 GPa at 1150 °C in the system CaO-MgO-Al2O3-SiO2-Cr2O3-Na2O, leading to phase assemblages enstatite ± forsterite ± diopside ± garnet. In enstatite coexisting with garnet, total OH is negatively correlated with pressure. Conversely, in Al-poor systems without garnet, total OH is positively correlated with pressure, and both ...

Data determined using a multianvil press are given for liquidus phase relations in the system diopside – forsterite – enstatite (CaMgSi2O6 – Mg2SiO4 – MgSiO3) and extend for a limited distance into the larger ternary system diopside – forsterite – quartz at 5.1 GPa. In the system diopside–enstatite, which cuts across the system diopside – forsterite – quartz and divides it into two smaller tern...

Introduction: Because they are dominated by enstatite, a nearly FeO-free pyroxene, and Si-bearing FeNi metal, along with minor amounts of unusual monosulfides such as niningerite (MgS), oldhamite (CaS) and alabandite (MnS), the enstatite chondrites have long been thought to have formed under extremely reducing conditions [1,2]. Like the ordinary chondrites, enstatite chondrites exhibit a range ...

sepiolite deposits have been recently discovered in northeastern iran. however, there is still little information about its physicochemical and mineralogical characteristics. therefore, the collapse of the sepiolite (with sizes of < 63 μm) structure induced by temperature elevation in an electric furnace at 350, 550, and 850 °c for 4 hours was studied using x-ray diffraction (xrd) in combinatio...

Enstatite is a ubiquitous phase in chondritic meteorites, interplanetary dust particles, and cometary samples. In equilibrium condensation models, enstatite predicted to condense via reaction between pre-condensed forsterite gaseous SiO. However, previous studies have shown that some enstatites chondrite matrices AOAs do not genetic relationship with forsterite, arguing against formation by the...

[1] EL chondrites exhibit larger average metal grain sizes than EH chondrites, a difference attributed by Easton [1983] to metamorphic coarsening, as most EL chondrites are equilibrated, and most EH chondrites are unequilibrated. In this paper, we present metal grain size data for three unequilbrated EL3 chondrites (PCA 91020; ALH 85119; MAC 88180) , and three EH3 chondrites (ALH 84170; PCA 910...