The Headless Tristan da Cunha Mantle Plume

Tiksheozero ultramafic-alkaline-carbonatite intrusive complex, like numerous carbonatite-bearing complexes of similar composition, is a part of large igneous province, related to the ascent of thermochemical mantle plume. Our geochemical and isotopic data evidence that ultramafites and alkaline rocks are joined by fractional crystallization, whereas carbonatitic magmas has independent origin. We suggest that origin of parental magmas of the Tiksheozero complex, as well as other ultramafic-alkaline-carbonatite complexes, was provided by two-stage melting of the mantle-plume head: 1) adiabatic melting of its inner part, which produced moderately-alkaline picrites, which fractional crystallization led to appearance of alkaline magmas, and 2) incongruent melting of the upper cooled margin of the plume head under the influence of CO2-rich fluids that arrived from underlying zone of adiabatic melting gave rise to carbonatite magmas.

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A THERMAL PULSE INDUCED BY PERMIAN MANTLE PLUME IN TARIM BASIN, SOUTHWEST CHINA, IMPLICATION FROM CLUMPED ISOTOPE THERMOMETRY, SOLID-STATE BOND REORDERING AND IN-SITU CALCITE U-PB DATING

10.1130/abs/2019am-331423 ◽

2019 ◽

Author(s):

Fuyun Cong ◽

◽

Jinqiang Tian ◽

Fang Hao ◽

...

Keyword(s):

Solid State ◽

Mantle Plume ◽

Tarim Basin ◽

Southwest China ◽

Thermal Pulse ◽

Clumped Isotope

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Cultural Contacts in an Isolated Community Tristan Da Cunha

American Journal of Sociology ◽

10.1086/220086 ◽

1947 ◽

Vol 53 (1) ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Peter A. Munch

Keyword(s):

Tristan Da Cunha

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A juvenile Tristan albatross (Diomedea dabbenena) on land at the Crozet Islands

Polar Biology ◽

10.1007/s00300-020-02786-0 ◽

2020 ◽

Author(s):

Alexander L. Bond ◽

Christopher Taylor ◽

David Kinchin-Smith ◽

Derren Fox ◽

Emma Witcutt ◽

...

Keyword(s):

Atlantic Ocean ◽

Cytochrome B ◽

Adult Male ◽

Mitochondrial Gene ◽

Small Population ◽

South Atlantic ◽

South Atlantic Ocean ◽

Tristan Da Cunha ◽

Gough Island ◽

Dispersal Events

AbstractAlbatrosses and other seabirds are generally highly philopatric, returning to natal colonies when they achieve breeding age. This is not universal, however, and cases of extraordinary vagrancy are rare. The Tristan Albatross (Diomedea dabbenena) breeds on Gough Island in the South Atlantic Ocean, with a small population on Inaccessible Island, Tristan da Cunha, ca 380 km away. In 2015, we observed an adult male albatross in Gonydale, Gough Island, which had been ringed on Ile de la Possession, Crozet Islands in 2009 when it was assumed to be an immature Wandering Albatross (D. exulans). We sequenced 1109 bp of the cytochrome b mitochondrial gene from this bird, and confirmed it to be a Tristan Albatross, meaning its presence on Crozet 6 years previous, and nearly 5000 km away, was a case of prospecting behaviour in a heterospecific colony. Given the challenges in identifying immature Diomedea albatrosses, such dispersal events may be more common than thought previously.

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