Titanium-rich oxide-bearing plagioclase-olivine inclusions in the unusual Ningqiang carbonaceous chondrite

Two plagioclase-olivine inclusions (POIs) from the unusual Ningqiang carbonaceous chondrite were studied to understand their mineralogy and crystallization history. In addition to the major phases plagioclase, spinel, olivine and pyroxene, Ningqiang POIs are characterized by interstitial assemblages composed of Ca-rich and Ca-poor pyroxenes, Ti-rich oxides and the other phases. The Ti-rich oxides include an unidentified titanium mineral series referred to as phase T, Ca-rich and Mg, Fe-rich armalcolites, geikielite, perovskite and rutile. This is the first reported occurrence of Ca-rich armalcolite and geikielite, and the second report of phase T in meteorites. Most of the constituent phases crystallized from the POI melts, and the Ti-rich oxides were the last phases in the crystallization sequence. Precipitation of the Ti-rich oxides may be related to the low abundance of Ca-rich pyroxene in the POIs