Microbial abundance and diversity in deep subsurface environments is dependent upon the availability of energy and carbon. However, supplies of oxidants and reductants capable of sustaining life within mafic and ultramafic continental aquifers undergoing low-temperature water-rock reaction are relatively unknown. We conducted an extensive analysis of the geochemistry and microbial communities r...

The Kap Edvard Holm Layered Series forms part of the East Greenland Tertiary Province, and was emplaced at shallow crustal level (at depths corresponding to a pressure of 1-2 kbar) during continental break-up. It consists of two suites: a gabbro suite comprising olivine and oxide gabbros, leucocratic olivine gabbros and anorthosites, and a suite of wehrlites that formed from the intrusion of th...

NWA 2700 and NWA 2977 Paired With NWA 773: NWA 2700 is a 31.7 gram stone consisting of small gabbro clasts plus regolith breccia matrix (see Figure 1). The olivine gabbro contains ~50 vol.% olivine (Fa29.3-34.7; FeO/MnO = 94), pigeonite (Fs2228.3Wo5.6-10; FeO/MnO = 52), augite (Fs13.2Wo38.5), plagioclase and minor maskelynite (An89), Ba-rich alkali feldspar (Or92An4, BaO up to 8.9 wt.%), Crspin...

The Sonju Lake intrusion (SLI) is a 1200-m thick, sheet-like, tholeiitic layered intrusion located within the 1096 Ma Beaver Bay Complex of NE Minnesota. Its cumulus stratigraphy of Ol Pl+Ol Pl+Cpx+Ol Pl+Cpx+Ox±Ol Pl+Cpx+Ox+Ol+Ap indicates formation by closed-system fractional crystallization of a tholeiitic magma. In 1999, outcrop sampling revealed a stratiform PGE-enriched interval within oxi...

RATIONALE We report new (87) Rb-(87) Sr isochron data for the Duluth Gabbro, obtained with a laser ablation resonance ionization mass spectrometer that is a prototype spaceflight instrument. The gabbro has a Rb abundance and a range of Rb/Sr ratios that are similar to those of KREEP-rich basalts found on the nearside of the Moon. Dating of previously un-sampled young lunar basalts, which genera...

The Neoproterozoic rocks of the Bir Madi area, south Eastern Desert, comprise a metagabbrodiorite complex (GDC) and a tonalite-granodiorite suite (TGrS). The GDC has a weak tholeiitic to strong calc-alkaline character and is made up of olivine gabbro, hornblende gabbro, diorite and monzodiorite. The olivine gabbro is characterized by abundance of augite and labradorite with pseudomorphic serpen...

Ž . Gabbroic sills intruding dunite in the crust–mantle transition zone MTZ of the Oman ophiolite have textures and compositions very similar to those in modally layered gabbros that form the lower part of the gabbro section in the ophiolite, and different from those in non-layered gabbros near the dike–gabbro transition. The presence of gabbroic sills in the MTZ indicates that modally layered ...

the bikilal layered gabbro-complex is composed of zones/layers of olivine/ pyroxene gabbro and hornblende gabbro. within the hornblende gabbro, repeated lens-like thin and elongated bodies of hornblendite are found intimately associated with massive and disseminated ilmenite-magnetite bodies, in places with apatite. petrological examination of the hornblende gabbro shows 50-55% hornblende, 40-4...

[1] Abstract: Analysis of crystal size distributions (CSD) of plagioclase in gabbros from the Oman ophiolite indicates that cooling rates in the lower crust beneath a mediumto fast-spreading oceanic ridge did not vary smoothly with depth. Cooling rates in the upper half of the gabbro section were approximately 1.5–2 times faster than in the lower half of the gabbro section during igneous crysta...