Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia
<p>The Southern Mountains area holds records of early geologic history of the Java island including magmatism-volcanism events as results of subduction along the Java trench since early Tertiary. Many Oligocene-Miocene volcanic rocks have been identified but the exact locations and ages of the...
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| Format: | Article |
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[Yogyakarta] : Departemnts of Geological Engineering Faculty of E
2009
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| _version_ | 1797031629767573504 |
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| author | , L.D. Setijadji |
| author_facet | , L.D. Setijadji |
| author_sort | , L.D. Setijadji |
| collection | UGM |
| description | <p>The Southern Mountains area holds records of early geologic history of the Java island including magmatism-volcanism events as results of subduction along the Java trench since early Tertiary. Many Oligocene-Miocene volcanic rocks have been identified but the exact locations and ages of their source centers are still poorly defined. On-going efforts to compile and generate new radiometric ages from undated Tertiary volcanic centers is here reported. Special attention is at Central-East Java, especially areas east of the Kulon Progo dome.<br />
Two dating campaigns were done, the first using K-Ar method and the second Ar-Ar method. Both were done on mineral separates, i.e. hornblende and/or plagioclase. The results produced reliable ages for four Middle-Upper Miocene volcanic centers surrounding the Yogyakarta city, i.e. Ponorogo (9.6:f:0.3 Ma), Borobudur or Menoreh (l2.4-11.4:f:0.7 Ma), Selogiri (l2.5:f:0.9 - 11.9:f:0.7 Ma) and Wediombo (13.22:f:0.62Ma). The first three volcanic centers are located along the northern margin of the Southern Mountains that represent the transitional zones between Tertiary (Southern Mountains) and Quaternary volcanic arcs. Our results confirm the overall trend suggested in Java's Sunda Arc in which magmatism migrated northward (toward the backarc-side) during Tertiary to Quaternary. Existing data show that the youngest Tertiary volcano has the age 9.6:f:0.3Ma (Ponorogo, Upper Miocene) which is directly overlain by the Quaternary Lawu volcano. Pliocene volcanic centers are yet to be found, but their volcanic products are present as distal acidic tephra layers as well as volcanic glass within sedimentary rocks and probably remnants of volcanic edifice at Gendol. Pliocene volcanoes are likely now covered by the Quaternary volcanic rocks.</p> |
| first_indexed | 2024-03-13T22:25:01Z |
| format | Article |
| id | oai:generic.eprints.org:95187 |
| institution | Universiti Gadjah Mada |
| last_indexed | 2024-03-13T22:25:01Z |
| publishDate | 2009 |
| publisher | [Yogyakarta] : Departemnts of Geological Engineering Faculty of E |
| record_format | dspace |
| spelling | oai:generic.eprints.org:951872014-11-28T07:35:34Z https://repository.ugm.ac.id/95187/ Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia , L.D. Setijadji <p>The Southern Mountains area holds records of early geologic history of the Java island including magmatism-volcanism events as results of subduction along the Java trench since early Tertiary. Many Oligocene-Miocene volcanic rocks have been identified but the exact locations and ages of their source centers are still poorly defined. On-going efforts to compile and generate new radiometric ages from undated Tertiary volcanic centers is here reported. Special attention is at Central-East Java, especially areas east of the Kulon Progo dome.<br /> Two dating campaigns were done, the first using K-Ar method and the second Ar-Ar method. Both were done on mineral separates, i.e. hornblende and/or plagioclase. The results produced reliable ages for four Middle-Upper Miocene volcanic centers surrounding the Yogyakarta city, i.e. Ponorogo (9.6:f:0.3 Ma), Borobudur or Menoreh (l2.4-11.4:f:0.7 Ma), Selogiri (l2.5:f:0.9 - 11.9:f:0.7 Ma) and Wediombo (13.22:f:0.62Ma). The first three volcanic centers are located along the northern margin of the Southern Mountains that represent the transitional zones between Tertiary (Southern Mountains) and Quaternary volcanic arcs. Our results confirm the overall trend suggested in Java's Sunda Arc in which magmatism migrated northward (toward the backarc-side) during Tertiary to Quaternary. Existing data show that the youngest Tertiary volcano has the age 9.6:f:0.3Ma (Ponorogo, Upper Miocene) which is directly overlain by the Quaternary Lawu volcano. Pliocene volcanic centers are yet to be found, but their volcanic products are present as distal acidic tephra layers as well as volcanic glass within sedimentary rocks and probably remnants of volcanic edifice at Gendol. Pliocene volcanoes are likely now covered by the Quaternary volcanic rocks.</p> [Yogyakarta] : Departemnts of Geological Engineering Faculty of E 2009 Article NonPeerReviewed , L.D. Setijadji (2009) Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia. text. http://repository.ugm.ac.id/digitasi/index.php?module=cari_hasil_full&idbuku=3005 |
| spellingShingle | , L.D. Setijadji Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia |
| title | Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia |
| title_full | Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia |
| title_fullStr | Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia |
| title_full_unstemmed | Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia |
| title_short | Updated Age Data of Volcanic Centers in the Southern Mountains of Central-East Java Island, Indonesia |
| title_sort | updated age data of volcanic centers in the southern mountains of central east java island indonesia |
| work_keys_str_mv | AT ldsetijadji updatedagedataofvolcaniccentersinthesouthernmountainsofcentraleastjavaislandindonesia |