Melanesian arc far-field response to collision of the Ontong Java Plateau: geochronology and petrogenesis of the Simuku Igneous Complex, New Britain, Papua New Guinea

Holm, Robert J., Spandler, Carl, and Richards, Simon W. (2013) Melanesian arc far-field response to collision of the Ontong Java Plateau: geochronology and petrogenesis of the Simuku Igneous Complex, New Britain, Papua New Guinea. Tectonophysics, 603. pp. 189-212.

[img] PDF (Published Version) - Published Version
Restricted to Repository staff only

View at Publisher Website: http://dx.doi.org/10.1016/j.tecto.2013.0...
 
16
2


Abstract

Understanding the evolution of the mid-Cenozoic Melanesian arc is critical for our knowledge of the regional tectonic development of the Australian-Pacific plate margin, yet there have been no recent studies to constrain the nature and timing of magmatic activity in this arc segment. In particular, there are currently no robust absolute age constraints at the plate margin related to either the initiation or cessation of subduction and arc magmatism. We present the first combined U–Pb zircon geochronology and geochemical investigation into the evolution of the Melanesian arc utilizing a comprehensive sample suite from the Simuku Igneous Complex of West New Britain, Papua New Guinea. Development of the embryonic island arc from at least 40 Ma and progressive arc growth was punctuated by distant collision of the Ontong Java Plateau and subduction cessation from26 Ma. This change in subduction dynamics is represented in the Melanesian arc magmatic record by emplacement of the Simuku Porphyry Complex between 24 and 20 Ma. Petrological and geochemical affinities highlight genetic differences between 'normal' arc volcanics and adakite-like signatures of Cu–Mo mineralized porphyritic intrusives. The contemporaneous emplacement of both 'normal' arc volcanics and adakite-like porphyry intrusives may provide avenues for future research into the origin of diverse styles of arc volcanism. Not only is this one of few studies into the geology of the Melanesian arc, it is also among the first to address the distant tectono-magmatic effects ofmajor arc/forearc collision events and subduction cessation on magmatic arcs, and also offers insight into the tectonic context of porphyry formation in island arc settings.

Item ID: 29388
Item Type: Article (Research - C1)
ISSN: 0040-1951
Keywords: Papua New Guinea; Melanesian arc; U-Pb geochronology; Arc geochemistry; Adakite; Ontong Java Plateau
Date Deposited: 18 Sep 2013 23:25
FoR Codes: 04 EARTH SCIENCES > 0403 Geology > 040313 Tectonics @ 30%
04 EARTH SCIENCES > 0403 Geology > 040304 Igneous and Metamorphic Petrology @ 40%
04 EARTH SCIENCES > 0403 Geology > 040303 Geochronology @ 30%
SEO Codes: 97 EXPANDING KNOWLEDGE > 970104 Expanding Knowledge in the Earth Sciences @ 80%
84 MINERAL RESOURCES (excl. Energy Resources) > 8401 Mineral Exploration > 840199 Mineral Exploration not elsewhere classified @ 20%
Downloads: Total: 2
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page