Time scales of pluton construction at differing crustal levels: Examples from the Mount Stuart and Tenpeak intrusions, North Cascades, Washington 论文

详细信息

发表期刊/会议

Geological Society of America Bulletin

发表日期

2006-11-01

发表年份

2006

摘要

Research Article| November 01, 2006 Time scales of pluton construction at differing crustal levels: Examples from the Mount Stuart and Tenpeak intrusions, North Cascades, Washington Jennifer E.P. Matzel; Jennifer E.P. Matzel 1Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Samuel A. Bowring; Samuel A. Bowring 1Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Robert B. Miller Robert B. Miller 2Department of Geology, San Jose State University, San Jose, California 95192, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Jennifer E.P. Matzel 1Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Samuel A. Bowring 1Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Robert B. Miller 2Department of Geology, San Jose State University, San Jose, California 95192, USA Publisher: Geological Society of America Received: 26 Oct 2005 Revision Received: 09 May 2006 Accepted: 10 Jul 2006 First Online: 03 Oct 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2006) 118 (11-12): 1412–1430. https://doi.org/10.1130/B25923.1 Article history Received: 26 Oct 2005 Revision Received: 09 May 2006 Accepted: 10 Jul 2006 First Online: 03 Oct 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jennifer E.P. Matzel, Samuel A. Bowring, Robert B. Miller; Time scales of pluton construction at differing crustal levels: Examples from the Mount Stuart and Tenpeak intrusions, North Cascades, Washington. GSA Bulletin 2006;; 118 (11-12): 1412–1430. doi: https://doi.org/10.1130/B25923.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Deciphering the magmatic history of continental magmatic arcs, in general, and the growth history of individual intrusions, in particular, is key to understanding the complex history of magma generation, segregation, and transport that define the dynamics of crustal growth. We utilize high precision U-Pb geochronology to resolve a detailed magmatic history from two composite intrusions, the 2–4 kbar Mount Stuart batholith and the 7–10 kbar Tenpeak pluton, emplaced in the Cretaceous North Cascades arc. This temporal framework provides a way to evaluate models of pluton growth that explain common features of intrusions such as concentric compositional zoning and internal magmatic contacts. U-Pb zircon crystallization ages were obtained from 12 samples of the Mount Stuart batholith and 8 samples of the Tenpeak intrusion, representing the range of compositional diversity and geographical extent.These dates indicate that the Mount Stuart batholith was constructed over a ∼5.5 m.y. time period that was punctuated by four intervals of high magma flux. The durations of the high-flux periods are short (a few hundred thousand years) relative to the duration of the batholith. The consistent pattern of magmatic fabrics and the lack of distinct contacts in the batholith may be explained by the juxtaposition of melt-rich and mush zones with subtle contacts between mineralogically and texturally similar tonalite and time-transgressive magma fabrics.In contrast, the Tenpeak intrusion was constructed over a ∼2.6 m.y. time period, with magma influx distributed throughout the intrusive history and texturally distinct magma bodies. The Tenpeak intrusion lacks distinct age domains, which suggests that any magma reservoir was smaller in size and potentially more ephemeral.Although the distinct age domains and discrete compositional and textural phases indicate that pluton growth occurred incrementally, neither pluton bears resemblance to a purely end-member incremental growth model whereby a pluton is constructed from hundreds to thousands of discrete magma pulses that have little, if any, interaction. In particular, ages from the youngest domain of the Mount Stuart batholith indicate that a melt-rich magma reservoir of ≥520 km3 existed over a 170 ± 90 k.y. time span. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.