This paper reports the detailed examination of three basalt clasts from Apollo 16 breccia 60639 that represent a new variant of high-Ti basalt returned from the Moon by the Apollo 16 mission. Mineral chemistry and whole-rock analyses were conducted on aliquots from three clasts (breccia matrix, basalt, and basalt + breccia matrix). The basalt clasts, which are not overtly porphyritic, contain c...

Harrat Lunayyir is a basaltic volcanic field in NW Saudi Arabia. Lava flows are basaltic to basanitic in composition, and the Holocene flows are alkali olivine basalts. The volcanic field contains about 50 cones that were constructed on Precambrian crystalline rocks along an N-S axis. The dominantly basaltic lavas of Harrat Lunayyir have been divided based on their erosion characteristics into ...

Introduction: Until recently, the SNC meteorites represented the only source of information about martian igneous processes [1]. This changed with the Mars Exploration Rovers which have analyzed basalts on the surface of Mars in both Gusev Crater and Meridiani Planum. These basalts are thought to be much older than the basaltic SNC meteorites [2] and have significantly different bulk chemistry ...

In the southeast of bam, there is a collection of volcanic rocks with andesite, basalt and trachy andesite composition. The texture of these rocks are often porphyritic with microlithic, porphyric cavity, and sometimes glomerulophorphuri, sore throat trachytic. Main minerals include Olivine, Clinopyroxene, Plagioclase and secondary minerals including opaque minerals, Iodenzyte, secondary Biotit...

This paper presents new U–Th/He crystallization and He exposure ages on olivine for a suite of basalt samples from the Snake River Plain, Idaho. The results provide the first demonstration that U–Th/He geochronology can be successfully applied to Late Quaternary basalts using measurements of olivine phenocrysts as opposed to U-rich minerals. The approach employs abrasion to remove the outer rin...

Small-scale assimilation of limestone during the intrusion of an olivine basalt feeder dyke into an Eocene argillaceous, siliceous biomicrite in the Tokatoka area has resulted in the incorporation of large amounts of calcium into the parent magma. Initial effects of assimilation have caused partial resorption of the earlyformed igneous mineralogy and the precipitation of calcic, iron-rich clino...