Mount Hampton Explained
Mount Hampton is a shield volcano with a circular ice-filled caldera. It is a twin volcano with Whitney Peak to the northwest and has erupted phonolite rocks. It is the northernmost of the volcanoes which comprise the Executive Committee Range in Marie Byrd Land, Antarctica and was active during the Miocene.
Geography and geology
Mount Hampton is the northernmost volcano of the Executive Committee Range in Marie Byrd Land, Antarctica. It has the form of a symmetrical uneroded shield volcano[2] with an "impressive" appearance and an ice-filled[3] 6.5x wide caldera.[4] Like other volcanoes in the Executive Committee Range, it is a paired volcano[5] with the northwesterly high Whitney Peak and the southeasterly high Marks Peak, which is the main summit of Mount Hampton.[6] The northwesterly summit is associated with its own caldera, which is partly cut by the Mount Hampton caldera on the southeastern flank and buried by the lava flows from the latter.[7] The centres of the two calderas are about apart.[8] Based on outcrops, it appears that most of the volcano is formed by flow rocks[9] but cinder and lava bombs occur at parasitic vents.[10]
The mountain rises about above the surface of the West Antarctic Ice Sheet[11] which buries most of the edifice, and moraine ridges are found at its base on the ice sheet.[12] Owing to climate conditions, the persistence of permanent ice atop of the mountain is unlikely over the long term;[13] erosion there appears to have been episodic[14] with maxima during interglacials[15] and there is no evidence of cirque formation.[16] Lichens have been found on the mountain.[17]
Composition
The volcano is formed by phonolite rocks, but parasitic vents have also erupted basanite[18] and Whitney Peak also erupted trachyte and benmoreite.[19] Hawaiite has been reported as well.[20] The volcanic rocks contain augite and feldspar; further, spinel-containing lherzolite xenoliths have been found.[21] In general, composition is unique for each volcano in the Executive Committee Range.[22]
Eruption history
Mount Hampton is one of the oldest volcanoes of Antarctica and was active during the Miocene.[23] Despite this, it is less eroded than some younger volcanoes in the region;[24] in general, the ages of the Marie Byrd Land volcanoes are not correlated to their erosion status.[25] It appears that Whitney Peak is the older half of the edifice and that volcanic activity then migrated to Mount Hampton.[26] More generally, volcanism in the Executive Committee Range migrated southwards over time at an average rate of 0.7cm/year, although Mount Hampton and its southern neighbour Mount Cumming were simultaneously active 10 million years ago.[27]
Last parasitic eruptions took place around 11.4 million years ago[28] and the youngest radiometric dates are 8.3 million years.[29] As at other volcanoes of Marie Byrd Land, the parasitic activity at Mount Hampton occurred after a long period of dormancy.[30] However, the presence around the caldera rim of snow-covered[31] inactive 10- high ice towers indicate that the mountain is geothermally active[32] and may have erupted during the Holocene.[33] Later research suggested that the ice towers were actually formed by wind-driven erosion of snow and ice. There is no evidence of geothermal processes[34] and seismic activity recorded at the volcano may be due to volcano-tectonic processes or due to ice movement.[35]
See also
Sources
- Carracedo . Ana . Rodes . Angel . Stuart . Finlay . Smellie . John . Understanding complex exposure history of Mount Hampton, West Antarctica using cosmogenic 3He, 21Ne and 10Be in olivine . EGUGA . April 2016 . EPSC2016–17178 . 2016EGUGA..1817178C . en. none.
- Carracedo . A. . Rodés . Á. . Smellie . J. L. . Stuart . F. M. . Episodic erosion in West Antarctica inferred from cosmogenic 3He and 10Be in olivine from Mount Hampton . Geomorphology . 15 February 2019 . 327 . 438–445 . 10.1016/j.geomorph.2018.11.019 . 2019Geomo.327..438C . 134667311 . en . 0169-555X. none.
- Volcanic geology of central Marie Byrd Land. Antarctic Journal of the United States. 3. 4. LeMasurier. W.E.. 90–91. none.
- Lemasurier . Wesley E. . Rocchi . Sergio . Terrestrial record of post‐eocene climate history in marie byrd land, west antarctica . Geografiska Annaler: Series A, Physical Geography . 1 March 2005 . 87 . 1 . 57 . 10.1111/j.0435-3676.2005.00244.x . 128880997 . 0435-3676. none.
- LeMasurier . Wesley E. . Wade . F. Alton . Fumarolic Activity in Marie Byrd Land, Antarctica . Science . 18 October 1968 . 162 . 3851 . 352 . 10.1126/science.162.3851.352 . 17836656 . 1968Sci...162..352L . 19337445 . en . 0036-8075. none.
- LeMasurier . W. E. . Rex . D. C. . Evolution of linear volcanic ranges in Marie Byrd Land, West Antarctica . Journal of Geophysical Research . 1989 . 94 . B6 . 7223 . 10.1029/JB094iB06p07223 . 1989JGR....94.7223L . en . 0148-0227. none.
- Lough . A. C. . Barcheck . C. G. . Wiens . D. A. . Nyblade . A. . Aster . R. C. . Anandakrishnan . S. . Huerta . A. D. . Wilson . T. J. . Subglacial volcanic seismicity in Marie Byrd Land detected by the POLENET/ANET seismic deployment . AGUFM . December 2012 . 2012 . T41B–2587 . 2012AGUFM.T41B2587L . en. none.
- Panter. K. S.. Wilch. T. I.. Smellie. J. L.. Kyle. P. R.. McIntosh. W. C.. 2021. Chapter 5.4b Marie Byrd Land and Ellsworth Land: petrology. Geological Society, London, Memoirs. en. 55. 1. 577–614. 10.1144/M55-2019-50. 233620473 . 0435-4052. none.
- Rocchi . Sergio . LeMasurier . Wesley E. . Vincenzo . Gianfranco Di . Oligocene to Holocene erosion and glacial history in Marie Byrd Land, West Antarctica, inferred from exhumation of the Dorrel Rock intrusive complex and from volcano morphologies . GSA Bulletin . 1 July 2006 . 118 . 7–8 . 991–1005 . 10.1130/B25675.1 . 2006GSAB..118..991R . en . 0016-7606. none.
- Book: LeMasurier . W. E. . Thomson, J. W. . Volcanoes of the Antarctic Plate and Southern Oceans . . 1990 . 0-87590-172-7 . 512 pp . none.
- Paleomagnetic investigations in Marie Byrd Land. Antarctic Journal of the United States. 3. 4. Scharon. L.. Early. T.. 92. none.
- antarid. GNIS.
- Wilch . T. I. . McIntosh . W. C. . Panter . K. S. . Chapter 5.4a Marie Byrd Land and Ellsworth Land: volcanology . Geological Society, London, Memoirs . 1 January 2021 . 55 . 1 . 515–576 . 10.1144/M55-2019-39 . 233632723 . en . 0435-4052. none. free .
Notes and References
- GNIS
- Carracedo et al. 2019, p.439
- GNIS
- Wilch, McIntosh and Panter 2021, p.546
- LeMasurier and Rex, 1989, p.7225
- LeMasurier and Thompson, 1990, p.194
- LeMasurier and Thompson, 1990, p.189
- Rocchi, LeMasurier and Vincenzo 2006, p.1001
- Rocchi, LeMasurier and Vincenzo 2006, p.997
- LeMasurier and Thompson, 1990, p.190
- Carracedo et al. 2019, p.439
- LeMasurier and Thompson, 1990, p.190
- Carracedo et al. 2019, p.442
- Carracedo et al. 2019, p.444
- Carracedo et al. 2016
- Lemasurier and Rocchi 2005, p.57
- Scharon and Early, p.91
- Carracedo et al. 2019, p.439
- LeMasurier and Rex, 1989, p.7228
- Panter et al. 2021, p.580
- Carracedo et al. 2019, p.439
- LeMasurier and Rex, 1989, p.7229
- Carracedo et al. 2019, p.439
- Rocchi, LeMasurier and Vincenzo 2006, p.997
- LeMasurier and Thompson, 1990, p.158
- LeMasurier and Thompson, 1990, p.189
- LeMasurier and Rex, 1989, p.7227
- Carracedo et al. 2019, p.439
- Carracedo et al. 2019, p.442
- LeMasurier and Thompson, 1990, p.197
- LeMasurier p.91
- LeMasurier and Wade, 1968
- LeMasurier and Thompson, 1990, p.193
- Wilch, McIntosh and Panter 2021, p.547
- Lough et al. 2012