why basalt contains rare earth

Role of recycled oceanic basalt and sediment in …

2007-12-20 · To calculate their initial isotope ratios at different times in Earth''s history, we assumed a linear relationship between the present-day isotopic ratios of average sediment and basalt and the ...

Basalt | Some Meteorite Information

Basalt is one of the most common rock types on Earth. Except for the coral, nearly all of the rocks of Hawaii are basalts. Much of Oregon and Idaho is covered with basalt. Basalt cobbles are commonly found on beaches, especially on volcanic islands (Hawaii, top). Most of the dark rocks in the bottom photo are basalts (Lake Superior).

Mobility of Rare Earth Elements in Basalt‐Derived Laterite …

2011-3-24 · Occurrence of florencite-(Ce) in a laterite profile derived from alkali basalt immobilizes REE (particularly LREE) and this leads the laterites to be enriched in LREE relative to the parent basalt. Few positive Ce anomalies in this profile suggest that florencite-(Ce) [(Ce)Al 3 (PO 4 ) 2 (OH) 2 ] formation was followed by CeO 2 precipitation ...

Basalt

Alkali basalt is a fine-grained dark color volcanic rock composed of phenocrysts of olivine, titanium rich and iron oxides (Fig. 4.40). Alkali basalt is relatively poor in silica and rich in sodium. It is silica unsaturated and contains feldspathoids (nepheline, leucite), alkali feldspar and phlogopite (magnesium mica) in the groundmass.

37. RARE EARTH AND OTHER TRACE ELEMENTS IN …

2007-5-11 · of the basalt is shown in Figure 3. In contrast to the basalts from Site 335, it shows relative enrichment of the lighter rare earths. The La/Sm ef is 2.13 and the Yb ef is 17.63. Both samples of plagioclase peridotite have RE contents below 1 ppm except for Yb and Ce which are slightly more than 1 ppm. Other trace element contents of the ...

basalt | Definition, Properties, & Facts | Britannica

basalt, extrusive igneous (volcanic) rock that is low in silica content, dark in colour, and comparatively rich in iron and magnesium. Some basalts are quite glassy (tachylytes), and many are very fine-grained and compact. It is more …

Mobility of Rare Earth Elements in Basalt‐Derived Laterite …

Mobility of Rare Earth Elements in Basalt-Derived Laterite at the Bolaven Plateau, Southern Laos. Kenzo SANEMATSU, ...,the occurrence of ion-adsorption type deposits appears to be scarce. In contrast, basalt contains abundant mafic minerals and volcanic glass, which are subject to alteration and weathering, with small amounts of insoluble ...

Basalt Rock | Formation, Properties, Composition, Uses

Basalt is the most common rock on Earth''s surface. Specimens are black in color and weather to dark green or brown. ... Basalt is an igneous rock that contains more than 45 and less than 52% of SiO2 and less than five percent of total alkalies (K2O + Na2O)3. Types of Basalt Basalt types: tholeiites vs alkali basalts. Tholeiitic basalt ...

The Rare Earth Content and Origin of Alkali-Rich Basalts

2020-9-5 · The rare earth content of alkali-rich, silica-undersaturated basalts erupted onto oceanic and continental plates is consistent with their derivation by slight amounts of partial melting of hydrous garnet peridotite at the top of the asthenosphere, within the low-velocity, low-Q zone of the mantle. The rare earths are fractionated during partial melting by retention of heavy rare …

The Rare Earth Content and Origin of Alkali-Rich Basalts

Basalt | Some Meteorite Information | Washington

Where is basalt in river sediments, and why does it matter ...

2014-12-1 · This strongly suggests that BR 938 contains anomalously high proportions of Al 2 O 3-rich clays and that its composition more likely reflects that of a suspended load. Finally, Fig. 2 shows that, compared to the Ganges sediments, suspended loads from the Chambal and Yamuna Rivers generally have lower Zr, Hf, Nb, Ta and Light Rare Earth Element ...