Tectonic inclusions within the New Idria serpentine body contain jadeite in two distinct assemblages: (1) Lenslike inclusions containing a monomineralic green jadeite core surrounded by a calc-silicate rim. (2) Jadeite veins cross-cutting albite-crossite schist inclusions. In these veins jadeite coexists with low albite; green jadeite (Jd 75 Ac+Di+He 25) coexists with low albite within the host...

Metapelitic rocks in the Gasht area include micaschist, kyanite schist, andalusite schist, garnet schist, staurolite schist, cordierite schist and sillimanite schist. Tourmaline occurs as accessory mineral in all of these rock types. These schists are metamorphosed regionally and are affected by contact metamorpism subsequently. Based on the textural relations and the fact that CaO and TiO2 con...

S U M M A R Y A 2-D upper crustal structural profile with seven steeply dipping faults was constructed from the Los Angeles Region Seismic Experiment phase II (LARSE II) seismic refraction data recorded over the north central Transverse ranges and adjacent Mojave desert in southern California. The profile extends to a depth of approximately 4 km. The faults were identified from distinctive feat...

The pyroclastic rocks of "The Crater", South Island, New Zealand belong to the Miocene, alkaline basaltic Dunedin Volcanic Group and represent an individual eruptive center with possible multiple vents. Three pyroclastic units have been separated at the study area based on textural and compositional features as well as their stratigraphic positions. The central part of The Crater comprises basa...

A chloritoid schist from the Medvednica Mts. (Croatia, Zagorje-Mid-Transdanubian zone) is part of metasedimentary succession a Palaeozoic-Mesozoic Metamorphic Complex. The studied samples show mineral association chloritoid, chlorite, quartz and white mica. P-T pseudosection, combined with modal chemical isopleths, classical thermobarometric calculations yield peak metamorphic conditions 0.8 – ...

This paper investigates the monazite grains from Dibrova rare-earth-thorium-uranium (U-Th-REE) mineral deposit within Azov Megablock of Ukrainian Shield. U-Th-REE mineralization is associated with K-feldspar-quartz metasandstones and metagritstones (hereafter quartzites) pegmatoids. The latter possibly represent products ultrametamorphism/granitization initially sedimentary clastic rocks during...

In this article, we for the first time fully describe geology and petrography of iron quartzite formation, localized in Southeast Guinea Simandou mountain range. region, a meridional distribution belt banded magnetite quartzites (itabirite) Lower Proterozoic metamorphic series has been mapped. The rocks form an extended (210 km) narrow (0.4-7 complex synclinal structure background Archean grani...

The Pelona, Orocopia, and Rand Schists and the schists of Portal Ridge and Sierra de Salinas constitute a high–pressure-temperature terrane that was accreted beneath North American basement in Late Cretaceous–earliest Tertiary time. The schists crop out in a belt extending from the southern Coast Ranges through the Mojave Desert, central Transverse Ranges, southeastern California, and southwest...