PETROLOGY OF HAKONE VOLCANO AND THE ADJACENT AREAS, JAPAN

Research Article| September 01, 1950 PETROLOGY OF HAKONE VOLCANO AND THE ADJACENT AREAS, JAPAN HISASHI KUNO HISASHI KUNO GEOLOGICAL INSTITUTE, TOKYO UNIVERSITY, JAPAN. Search for other works by this author on: GSW Google Scholar GSA Bulletin (1950) 61 (9): 957–1020. https://doi.org/10.1130/0016-7606(1950)61[957:POHVAT]2.0.CO;2 Article history received: 24 Jun 1948 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation HISASHI KUNO; PETROLOGY OF HAKONE VOLCANO AND THE ADJACENT AREAS, JAPAN. GSA Bulletin 1950;; 61 (9): 957–1020. doi: https://doi.org/10.1130/0016-7606(1950)61[957:POHVAT]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 SocietyGSA Bulletin Search Advanced Search Abstract Rocks of Hakone volcano and adjacent areas cover a wide range from basalt to dacite approximate to soda-rhyolite. They were erupted from various different centers during the period from older Miocene to Recent.Two different rock series are recognized, one characterized by the occurrence of monoclinic-pyroxene (a solid solution series from augite to iron-rich pigeonite) as the only pyroxenic phase of the groundmass; the other by the presence of hypersthene (sometimes together with augite) in the groundmass. They are designated as "pigeonitic rock series" and "hypersthenic rock series" respectively. The pigeonitic rock series was derived from a parental olivine-basalt magma through simple fractional crystallization; the hypersthenic rock series was formed from the same magma through contamination of acid igneous rocks (probably granitic).In the pigeonitic rock series, the crystallization of the groundmass pyroxenes took place over the clino- and orthopyroxene inversion temperatures, resulting in pigeonite. In the hypersthenic rock series, the crystallization temperatures were lowered by concentration of volatile substances due to the contamination; its crystallization took place always below the inversion temperature, resulting in hypersthene. Porphyritic hornblende appeared in the later stage of the crystallization of the latter series.The chemical compositions of the groundmasses of these rocks resemble those of basalts and dolerites of the tholeiitic magma-type of the world. 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.