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...

Introduction: The lunar meteorites Miller Range 05035 (MIL) and Meteorite Hills 01210 (MET) were collected during the 2005 and 2001 ANSMET (Antarctic Meteorite Search) field seasons [1,2]. MET is a 22.8 g regolith breccia composed primarily of basaltic material [3-6]. MIL is a 142.2 g coarse-grained basalt [2]. The bulk composition, mineral assemblage, and texture of MIL is similar to lunar met...

systematics of the ultra-high temperature Napier Complex, East Antarctica: Evidence for the early Archean differentiation of Earth's mantle" (2007). Related Publications from ANDRILL Affiliates. Paper 15. Figure 1. Outcrop map of the western Napier Complex, East Antarctica. Areas of outcrop are indicated in black. The approximate extent of UHT mineral assemblages (UHT-zone) is indicated by the ...

[1] Jarosite occurs within altered tephra from the saline‐alkaline paleolake deposits of Pliocene‐Pleistocene Olduvai Gorge, Tanzania. Zeolites (mainly phillipsite), authigenic K‐feldspar, and Mg/Fe‐smectites dominate the mineral assemblage, indicating saline‐ alkaline diagenetic conditions (pH > 9). As jarosite is ordinarily an indicator of acidic conditions on Earth and Mars, its association ...

for the first time, an unusual assemblage of talc-phengite-chlorite-k-feldspar was found in quartz schists from the sanandaj-sirjan zone in the nahavand area in western iran. the talc-bearing quartz schists occur as small bodies or lenses within pelitic schist layers and contain talc, phengite, chlorite, k-feldspar and quartz as major mineral constituents with subordinate amounts of calcite ...

Studies dealing with the response of the continental biosphere to the environmental perturbations associated with Cretaceous oceanic anoxic events (OAEs) are comparatively rare. Here, a quantitative spore-pollen record combined with clay mineral data is presented, which covers the entire early Aptian OAE 1a interval (Forcall Formation, Maestrat basin, east Spain). The well-expressed OAE 1a carb...