Composition of chromian diopside megacryst in DSDP Leg 37 basalts (Table 2, 3)

• Main Authors: Donaldson, Colin H, Brown, Roy W
• Format: Dataset
• Language: English
• Published: PANGAEA 1977
• Subjects: 37-332A; 37-332B; 37-335; Aluminium oxide; Calcium oxide; Chromium; Chromium(III) oxide; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; DSDP/ODP/IODP sample designation; Elevation of event; Enstatite; Event label; Ferrosilite; Glomar Challenger; Iron oxide; Fe2O3; FeO; Latitude of event; Leg37; Lithology/composition/facies; Longitude of event; Magnesium number; Magnesium oxide; Manganese oxide; North Atlantic; North Atlantic/VALLEY; Potassium oxide; Sample code/label; Silicon dioxide; Sodium oxide; Titanium dioxide; Wollastonite; Greenland; Pacific
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.708792; https://doi.org/10.1594/PANGAEA.708792

Refractory megacrysts of olivine, plagioclase, chromian diopside and Cr-Al spinel, which were not in equilibrium with the host oceanic tholeiite on eruption, are present in samples from several dredge sites and DSDP drill sites in the Atlantic and Pacific Oceans. They have multiple origins: (1) cognate or accidental mantle fragments; (2) relict fragments from fractional crystallization of parental liquids considerably more primitive than oceanic tholeiite; and most commonly (3) the fractional crystallization products of such liquids mixed with oceanic tholeiite magma. Melt inclusions in chrome-spinel phenocrysts provide evidence for this postulated Mg- and Ca-rich magma which has counterparts in the Scottish Tertiary Province and in west Greenland.