کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4698455 1637560 2015 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ultra-depleted melts in olivine-hosted melt inclusions from the Ontong Java Plateau
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Ultra-depleted melts in olivine-hosted melt inclusions from the Ontong Java Plateau
چکیده انگلیسی


• The Ontong Java Plateau (OJP) is the largest large igneous province on Earth.
• We report the first major, trace and volatile element data on OJP melt inclusions.
• Some of the OJP melt inclusions exhibit ultra-depleted trace element patterns.
• These are the first ultra-depleted melts found in the OJP.
• These melts require the presence of a highly depleted mantle source beneath OJP.

The Ontong Java Plateau (OJP) represents the largest large igneous province (LIP) preserved in the geologic record. The most voluminous volcanic types of the OJP—the Kroenke and Kwaimbaita groups, which dominate the accessible portions of the plateau—have relatively flat primitive mantle normalized rare earth element (REE) patterns. With the exception of relatively small volumes of late-stage melts—referred to as the Singgalo group—that are characterized by slightly enriched REE patterns relative to a chondritic pattern, the volcanic groups that dominated the eruptive history of the OJP exhibit remarkably homogeneous, flat REE patterns. Here we isolate, for the first time, olivine-hosted melt inclusions from the OJP. We show that the melt inclusions have two clear populations defined by distinct trace element characteristics. The first population has relatively flat trace element patterns that are similar to those observed in whole rock lavas from the most voluminous volcanic groups (Kroenke and Kwaimbaita) recorded in the OJP. In contrast, a second group of melt inclusions, referred to as UDM (ultra-depleted melt) inclusions, exhibit (light-REE) LREE-depleted patterns relative to a chondritic pattern; these trace element patterns are far more depleted than any previously reported lava from OJP. The UDM have unique trace element signatures that preclude an origin by re-melting the depleted mantle source left over after melt extraction during construction of the OJP. We interpret the new UDM compositions to be the result of melting a previously unrecognized (in lavas) ultra-depleted component hosted in the OJP mantle source.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Geology - Volume 414, 30 October 2015, Pages 124–137
نویسندگان
, , , , , , ,