Tasmantid Seamount Chain
Topographic map of Zealandia that includes the unlabelled Tasmantid Seamount Chain (above the label Australia) off the east of Australia extending from the Coral Sea southwards into the Tasman Sea.
Map
[Interactive fullscreen map + nearby articles]
Tasmantid Seamount Chain (red - coral reefs, yellow - seamounts if Wikipedia Graph module enabled)
Location
LocationCoral and Tasman seas
Coordinates31°00′S 156°00′E / 31.000°S 156.000°E / -31.000; 156.000
Geology
TypeSeamount chain
Age of rock56–7 Ma[1]

The Tasmantid Seamount Chain (alternatively Tasmantid Seamounts, Tasman Seamounts, Tasman Seamount Chain, Tasmantide Volcanoes or the Tasmantids)[2] is a 2,000 km (1,200 mi) long chain of seamounts in the South Pacific Ocean. The chain consists of over 16 extinct volcanic peaks, many rising more than 4,000 m (13,000 ft) from the seabed.[3][4][5] It is one of the two parallel seamount chains alongside the East Coast of Australia; the Lord Howe and Tasmantid seamount chains both run north-south through parts of the Coral Sea and Tasman Sea. These chains have longitudes of approximately 159°E and 156°E respectively.[6]

Like its neighbour, the Tasmantid Seamount Chain has resulted from the Indo-Australian Plate moving northward over a stationary hotspot.[7] It ranges in age from about 56 to 7 million years old.[3]

Features

The Tasmantid Seamount Chain includes the following named seamounts:

Tasmantid Seamounts
Seamount Location Age[Age note 1] Notes
Gascoyne Seamount 36°41′00″S 156°07′00″E / 36.68333°S 156.11667°E / -36.68333; 156.11667 7.13 ± 0.07 Ma [8][9][1]
Kimbla Seamount 35°06′37″S 156°28′32″E / 35.110323°S 156.475641°E / -35.110323; 156.475641 [3] [5]
Taupo Bank 33°10′00″S 156°10′00″E / 33.166667°S 156.166667°E / -33.166667; 156.166667 10.3 to 11.4 Ma [8][9]
Barcoo Bank 32°35′00″S 156°15′00″E / 32.58333°S 156.25°E / -32.58333; 156.25 [8]
Derwent Hunter Guyot 30°52′00″S 156°11′00″E / 30.86667°S 156.18333°E / -30.86667; 156.18333 16.83 ± 0.1 Ma [8][1]
Stradbroke Seamount 29°05′00″S 155°45′00″E / 29.08333°S 155.75°E / -29.08333; 155.75 [8]
Britannia Guyots 28°17′00″S 155°38′00″E / 28.28333°S 155.63333°E / -28.28333; 155.63333 17.6 to 23 Ma [8][9]North, Central and South Seamounts[3] Central Britannia 23.0± 0.2 Ma, South Britannia age 21.68 ± 0.17 Ma[1]
Queensland Guyot 27°35′00″S 155°11′00″E / 27.58333°S 155.18333°E / -27.58333; 155.18333 20.9 Ma [8][9]
Brisbane Guyots 26°59′00″S 155°05′00″E / 26.98333°S 155.08333°E / -26.98333; 155.08333 27.28 ± 0.15 [8]Age is North Brisbane[1] North and South Brisbane Seamounts[3]
Mooloolaba Seamount 26°20′S 154°52′E / 26.33°S 154.87°E / -26.33; 154.87 [5]
Moreton Seamounts 26°01′00″S 154°58′00″E / 26.01667°S 154.96667°E / -26.01667; 154.96667 [8]North and South Moreton[3]
Recorder Guyots 25°10′00″S 154°55′00″E / 25.16667°S 154.91667°E / -25.16667; 154.91667 26.4 to 30.0 Ma North Recorder is younger[1]Named from the British cable ship "Recorder"[8] North and South Recorder Seamounts[3]
Fraser Seamounts 24°26′00″S 155°17′00″E / 24.43333°S 155.28333°E / -24.43333; 155.28333 26.4 ± 0.2 Ma [8]Age South Frazer[1] North and South Fraser[3] Not to be confused with Fraser Island.
Cato Reef 23°13′S 155°34′E / 23.217°S 155.567°E / -23.217; 155.567 31.25 ± 0.16 Ma [1][8]Coral reef
Wreck Reefs 22°11′S 155°20′E / 22.183°S 155.333°E / -22.183; 155.333 31.7 to 32.9 Ma [8][1][10]Coral reef
Kenn Reef 21°12′S 155°43′E / 21.200°S 155.717°E / -21.200; 155.717 [8]Coral reef
Mellish Reef 17°25′00″S 155°50′00″E / 17.41667°S 155.83333°E / -17.41667; 155.83333 [8]Most northern coral reef of seamount chain[10]

There is an unnamed seamount between Stradbroke Seamount and Derwent Hunter Guyot and 7 unnamed seamounts in the Coral Sea near Mellish Reef that have been assigned to the chain.[1] Some of the later have age ranges between 37.0 to 50.5 Ma.[1] Also assigned to the chain are two sampled areas of the southern Louisiade Plateau with ages of 56.40 ± 0.60 and 55.00 ± 0.40 Ma respectively that are believed to represent the most northern aspects of the chain.[1]

Geology

Main article: Tasmantid hotspot

The volcanics are saturated tholeiitic to transitional alkali-olivine basalt.[1]

Age note

  1. ^ Only limited sampling and age studies have been done. Ages are available on some of the eleven dredging samples analysed by Eggins et al.(1991) by K/Ar absolute methodology and some of 32 later samples by the 40Ar39Ar relative methodology. While different specimens from Gascoyne Seamount matched on age, different specimens from Britannia Guyots mismatch by 5 million years odd by the two different methodologies. However adjacant volcanoes can have long eruptive histories. 40Ar39Ar age subsample data as presented in conference proceedings in 2015 is sourced from the appendix published by Douglas(2022).

References

  1. ^ a b c d e f g h i j k l m Douglas (Smethurst), Amelia. The East Australian, Tasmantid and Lord Howe volcanoes : exploring the origins of three, contemporaneous, parallel chains of volcanism. (PhD thesis and appendix) (Thesis). doi:10.7488/era/2805. Retrieved 2023-03-30.
  2. ^ "Marine Gazetteer Placedetails". Retrieved 2017-02-20.
  3. ^ a b c d e f g h "Tasmantid Seamounts of Australia". Retrieved 2017-02-20.
  4. ^ Richards, F. D.; Kalnins, L. M.; Watts, A. B.; Cohen, B. E.; Beaman, R. J. (October 2018). "The Morphology of the Tasmantid Seamounts: Interactions Between Tectonic Inheritance and Magmatic Evolution" (PDF). Geochemistry, Geophysics, Geosystems. 19 (10): 3870–3891. doi:10.1029/2018GC007821. hdl:20.500.11820/10f58983-8003-4af7-8fdd-def2ed23b0be. S2CID 133360937.
  5. ^ a b c Richards, F. D.; Kalnins, L. M.; Watts, A. B.; Cohen, B. E.; Beaman, R. J. (2018). "The Morphology of the Tasmantid Seamounts: Interactions Between Tectonic Inheritance and Magmatic Evolution". Geochemistry, Geophysics, Geosystems. doi:10.1029/2018GC007821. hdl:10044/1/74307.
  6. ^ Van Der Linden, Willem J. M. (1970). "Morphology of the Tasman sea floor". New Zealand Journal of Geology and Geophysics. 13: 282–291. doi:10.1080/00288306.1970.10428218.
  7. ^ W. J. Morgan and J. P. Morgan. Plate velocities in hotspot reference frame: electronic supplement.
  8. ^ a b c d e f g h i j k l m n o "GEBCO Undersea Feature Names Gazetteer".
  9. ^ a b c d Eggins, S. M.; Green, David Headley; Falloon, Trevor J. (1991). "The Tasmantid seamounts: Shallow melting and contamination of an EM1 mantle plume". Earth and Planetary Science Letters. 107 (3–4): 448–462. doi:10.1016/0012-821X(91)90092-V.
  10. ^ a b "Coral Sea Marine Park - Management Plan 2018" (PDF). Retrieved 2023-03-29.
Categories