Minerals recovered from the deep mantle provide a rare glimpse into deep Earth processes. We report the first discovery of ferric iron-rich majoritic garnet found as inclusions in a host garnet within an eclogite xenolith originating in the deep mantle. The composition of the host garnet indicates an ultrahigh-pressure metamorphic origin, probably at a depth of ~200 km. More importantly, the fe...

The 465 Ma Svarthopen pluton in northcentral Norway was emplaced under middle-crustal conditions (~700 MPa) into metasedimentary rocks of the Helgeland Nappe Complex. The pluton is characterized by zones of mingling and mixing of gabbro/ diorite with peraluminous, garnet-bearing biotite granite. Variation in bulk-rock Sr and Nd isotope ratios are consistent with simple mixing; however, nonunifo...

Introduction: The presence of garnet in the lunar mantle has been debated from many years (e.g., [1-3]). Data from the Apollo seismic network were unable to unambiguously resolve a garnet signature in the lower mantle. For example, higher seismic velocities in the lunar mantle (>500 km) could be indicative of an increased proportion of Mg-rich olivine [2,4], or be due to the presence of garnet ...

This paper presents Garnet, a novel spatial hypertext interface to a digital library. Garnet supports both information structuring – via spatial hypertext – and traditional information seeking – via a digital library. A user study of Garnet is reported, together with an analysis of how the organizing work done by users in a spatial hypertext workspace could support later information seeking. Th...

The effects of exchange coupling on magnetic switching properties of all-garnet multilayer thin film structures are investigated. All-garnet structures are fabricated by sandwiching a magneto-soft material of composition type Bi1.8Lu1.2Fe3.6Al1.4O12 or Bi₃Fe₅O12:Dy₂O₃ in between two magneto-hard garnet material layers of composition type Bi₂Dy₁Fe₄Ga₁O12 or Bi₂Dy₁Fe₄Ga₁O12:Bi₂O₃. The fabricated ...

Many geochemical models of major igneous differentiation events on the Earth, the Moon, and Mars invoke the presence of garnet or its high-pressure majoritic equivalent as a residual phase, based on its ability to fractionate critical trace element pairs (Lu/Hf, U/Th, heavy REE/light REE). As a result, quantitative descriptions of mid-ocean ridge and hot spot magmatism, and lunar, martian, and ...

We report on magnetization dynamics triggered in a Co/garnet heterostructure by femtosecond laser pulses. Although laser excitation of a bare Co-doped yttrium iron garnet leads to magnetization precession, the phase of which strongly depends on the linear polarization of the light pulses, the deposition of an ultrathin Co layer on a top of a garnet film results in substantial changes of the las...

Quartz inclusion thermobarometry utilizes the pressureand temperature-sensitive Raman peak shifts of quartz inclusions in garnet to determine formation pressure and temperature (PT) conditions. The measured Raman shift indicates the pressure currently retained in the inclusions at ambient external conditions, such that entrapment PT conditions (i.e., P and T of garnet growth) can be determined ...

Temperature estimates obtained with various biotite-garnet thermometers are inconsistent in granulite facies rocks. Although the inconsistency lies partly in the lack of definition of equilibrium criteria, it still remains after rigorous selection of analyzed mineral pairs (isolated biotite and garnet cores for peak equilibrium conditions) and originate from minor element effects in garnet and ...

Mineral compositions and reaction textures found in migmatitic gneisses from near Gilsum, New Hampshire, constrain both peak metamorphic pressure (P) and temperature (T) conditions and the PT path. Large K-feldspar porphyroblasts indicate isobaric heating of the samples at P < 4 kb (Spear et al. 1999), and relict cordierite + garnet assemblages record the occurrence of biotite vapor-absent melt...