DOI: 10.1016/J.CHEMGEO.2007.04.009 Corpus ID: 128902230; Chemical and isotopic relationships between peridotite xenoliths and mafic–ultrapotassic rocks from Southern Brazil
Listvenites form by metasomatic transformation of variably serpentinized peridotites to carbonate-quartz rocks due to extensive reaction with CO 2-bearing aqueous fluids.This transformation sequesters large amounts of carbon since listvenites commonly contain >30 wt% CO 2.Although volumetrically a rare rock type, they occur in many …
We call ultramafic rocks rich in olivine, peridotite. Those that are less than half olivine are pyroxenites. Other names, shown in the figure, divide peridotites and pyroxenites into smaller classes. Many …
Peridotites are dense, coarse-grained, dark-colored ultramafic plutonic rocks with at least 40% olivine by volume. Members are dunite, kimberlite, harzburgite, …
Agashev, A. M. et al. Metasomatism in lithospheric mantle roots: constraints from whole-rock and mineral chemical composition of deformed peridotite xenoliths from kimberlite pipe Udachnaya ...
Peridotite is the ultimate source of all chromium ore and naturally occurring diamonds, and of nearly all chrysotile asbestos. It is one of the main host rocks of talc deposits and …
Bits of these rocks—peridotite, dunite, lherzholite and others-- may be squeezed to the surface when continental plates collide with oceanic plates, or, less often, when the interiors of continents thin and develop rifts. Because of their chemical makeup, when the rocks are exposed to carbon dioxide, they react to form common limestone …
The vertical sequence of ophiolites, typically ranging from basal ultramafic to upper mafic rocks (Fig. 1), shares certain similarities with layered mafic-ultramafic complexes, and intrusive relationships between the basal and upper units are commonly observed in many ophiolites (e.g., Steinmann, 1927; Fig. 1).Consequently, the …
the rocks known, only the ultramafic rocks dunite, eclogite, and peridotite have geophysical properties that match those of the upper mantle. Most geologists have concluded from this and other evidence that the mantle itself is made up of ultramafic rock. Thus the peridotite nodules in oceanic
garnet peridotite) and lower crustal rocks (granulite, calc silicate rock and garnet gneiss) are locally present as tectonic slices, mostly along the ... al. (1995). The rock is composed of garnet-
Peridotite residue compositions are important functions of the pressures of initial and final decompression melting. At constant MgO, increasing pressure of initial melting will produce residues that are lower in FeO (), higher in Al 2 O 3 and higher in SiO 2 ().When the pressure of initial melting is 2–3 GPa, residues can be strongly depleted in …
The studied cratonic peridotites are characterised by three main modes of olivine; low (63–68%), medium (76–82%), and high (>93%), with low olivine peridotites having complementary high modal ...
The high TiO 2 and moderate Al 2 O 3 contents of chromite in the metamorphic rock are different from those of arc basalt, large igneous province (LIP), …
Peridotite is one of the main rock types that make up the Earth's mantle, which is the solid layer of the Earth that lies below the crust and extends to a depth of about 2,900 kilometers (1,800 miles). The occurrence and distribution of peridotite in the Earth's mantle are fundamental to our …
The extraction of abiogenic H 2 from the earth as an energy resource[1] is a possibility raised by the recognition that ultramafic rocks yield hydrogen in the course of serpentinization [2–5], through which water is reduced to H 2 as ferrous iron from peridotite minerals oxidizes. Given the straightforward oxidation of iron silicate to magnetite to …
The formation of sheared peridotite rocks and other mantle rocks containing unequilibrated features, such as strongly zoned minerals or deformation textures, is consistent with infiltration of the ...
González-Jiménez, J. M. et al. Transfer of Os isotopic signatures from peridotite to chromitite in the subcontinental mantle: insights from in situ analysis of platinum-group and base-metal ...
Sometimes extrusive igneous rocks cool so quickly that no crystals form. This is especially likely to happen if lava meets water. The result is a rock composed of volcanic glass called obsidian.Examples of obsidian appeared in Figures 1.21 (Chapter 1) and Figure 4.5 (Chapter 4). In other cases, different minerals may grow to distinctly different sizes.
Request PDF | Petrological evidence of an anhydrous carbonatitic peridotite source for the Xiaogulihe ultrapotassic volcanic rocks, northeastern China | This study presents new olivine and whole ...
They also propose to grind the peridotite rock and mix it with the liquefied carbon dioxide. "The process needs more research as drilling operations are very costly," Al Hashmi said.
The dominant rock type is peridotite (93%) that is cut by dykelets and dykes of coarse-grained magmatitc rocks (3.8%) comprising gabbro, gabbronorite, olivine gabbro, and troctolite (Cannat et al., 1997) …
Although a genetic link between high-Mg TTG and adakitic rocks and reaction of melt with mantle peridotite has been suggested based on studies of mantle xenoliths and experimental grounds (Yaxley and Green, 1998, Rapp et al., 1999, Thompson and Gibson, 2000, Scambelluri et al., 2006), physical evidence is scarce (Liu et al., …
A study of whole-rock chemistry of Expedition 357 peridotite (Whattam et al., 2022) showed that M0071 western serpentinite and M0069 central site peridotite exhibit trace element patterns akin to MOR serpentinite dominated by fluid–rock reactions, whereas the remaining central sites M0072 and M0076 and eastern site serpentinite …
Olivine usually occurs in igneous rocks such as basalt, dunite, gabbro, diabase, or peridotite, and it is often green in color. At surface levels, olivine is commonly found in dark-colored igneous rocks. …
The Xiaogulihe volcanic rocks are situated within the northernmost EWKX volcanic belt (Fig. 1 a) and have the highest K contents and most enriched Sr–Nd–Pb isotopic compositions (Fig. 2; Shao et al., 2009; Sun et al., 2014) of the rocks within the belt.This makes them ideal for examining the petrogenesis of the magmas that formed …
Another possible process for creating layers within the Horoman peridotite is melt-rock reaction with or without melting in an open system; for example, melt-rock reactions involving dissolution of garnet and pyroxenes and precipitation of olivine (Kelemen, 1990; Kelemen et al., 1992; Kelemen et al., 1995; Ozawa and Shimizu, 1995; Verniéres et ...
Figure 3 Sm-Nd Model age dating from garnet peridotite (Kadarusman et al, 2002) Figure 4 Mineral assemblages of peridotites, ... gneiss and eclogite-facies rocks (Kadarusman et al., 2005 ...
Data for the NCC lower crust and upper crust are from Jahn et al. (1999), the YC lower crust from Chen and Jahn (1998), the north Dabie mafic rocks from Jahn et al. (1999) and Li et al. (1998), the UCC from Jahn et al. (1988), Fangcheng basalts from Zhang et al. (2002), and Feixian basalt from Pei et al. (2004), the Cenozoic mantle peridotite ...
We selected five representative spinel lherzolite peridotite xenolith samples from Jeju Island for this study. Sample numbers, locations, field photographs, and xenolith photographs are provided ...
Peridotite is an ultramafic plutonic rock containing 40– olivine (from peridot, French for olivine); other essential minerals include clinopyroxene and orthopyroxene; common …
The abyssal peridotite compilation presented here includes samples from six major mid-ocean ridges, from a total of 282 sites at 35 transform fault and 18 ridge segment localities (Fig. 1).While the term abyssal peridotite can refer to any seafloor sample of ultramafic rock, samples from subduction zones have been excluded as their …
Pyroxene (either orthopyroxene or clinopyroxene), olivine, and (less commonly) plagioclase are the dominant minerals in these rocks. The IUGS system, shown in Figure 6.117, names ultramafic rocks based on their relative amounts of olivine, orthopyroxene, and clinopyroxene. We call ultramafic rocks rich in olivine, peridotite.
Here, the authors show that hydrothermal alteration and chemical weathering of ultramafic rock compensates for the low Ni and Cr concentrations of …
oxidized through prior water/rock reaction (Mayhew et al., 2018; Ellison et al., 2021), H 2 is continually being produced by modern ... peridotite rocks and fluids, and they exhibit highly variable rates of activity across geochemical gradients (Fones et al., 2019, 2022;
