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Angular, oriented microtubes in metamorphic plagioclase

1980; Geological Society of America; Volume: 8; Issue: 5 Linguagem: Inglês

10.1130/0091-7613(1980)8 2.0.co;2

1943-2682

Steven B. Shirey, Gene Simmons, Elaine R. Padovani,

Geomagnetism and Paleomagnetism Studies

Research Article| May 01, 1980 Angular, oriented microtubes in metamorphic plagioclase Steven B. Shirey; Steven B. Shirey 1Department of Earth and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Search for other works by this author on: GSW Google Scholar Gene Simmons; Gene Simmons 1Department of Earth and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Search for other works by this author on: GSW Google Scholar Elaine R. Padovani Elaine R. Padovani 1Department of Earth and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Search for other works by this author on: GSW Google Scholar Author and Article Information Steven B. Shirey 1Department of Earth and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Gene Simmons 1Department of Earth and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Elaine R. Padovani 1Department of Earth and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1980) 8 (5): 240–244. https://doi.org/10.1130/0091-7613(1980)8 2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Steven B. Shirey, Gene Simmons, Elaine R. Padovani; Angular, oriented microtubes in metamorphic plagioclase. Geology 1980;; 8 (5): 240–244. doi: https://doi.org/10.1130/0091-7613(1980)8 2.0.CO;2 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 SocietyGeology Search Advanced Search Abstract Angular, oriented microtubes are abundant in oligoclase in medium-grained gneiss from southeastern Pennsylvania. The microtubes are isolated, elongate voids that extend through the thin section with rectangular to square cross sections ∼2 μm on a side.The microtubes occur in planar sets of from 5 to 40 equal-sized individuals, spaced 2 to 5 μm apart; single occurrences have never been observed. The walls are either parallel or perpendicular to [010] of the host. Oligoclase also contains open intragranular cracks with zigzag morphology and matching, stair-step–shaped walls. We suggest that angular, oriented microtubes form by displacement and healing along zigzag intragranular cracks. This hypothesis explains unique properties of microtubes: regular spacing, equal size, rectangular cross section, crystallographically controlled orientation, and existence in sets. Angular, oriented microtubes are perhaps indicators of fracturing under conditions of low in situ confining pressure followed by release of shear stress along microcrack planes. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.