TY - JOUR

T1 - Distribution of oceanic crust in the Enderby Basin offshore East Antarctica

AU - Altenbernd-Lang, Tabea

AU - Jokat, Wilfried

AU - Leitchenkov, German L.

N1 - Tabea Altenbernd-Lang, Wilfried Jokat, German L Leitchenkov, Distribution of oceanic crust in the Enderby Basin offshore East Antarctica, Geophysical Journal International, Volume 231, Issue 3, December 2022, Pages 1959–1981, https://doi.org/10.1093/gji/ggac299

PY - 2022/8/24

Y1 - 2022/8/24

N2 - Seismic reflection and refraction data were collected in 2007 and 2012 to reveal the crustal fabric on a single long composite profile offshore Prydz Bay, East Antarctica. A P-wave velocity model provides insights on the crustal fabric, and a gravity-constrained density model is used to describe the crustal and mantle structure. The models show that a 230-kmwide continent–ocean transition separates stretched continental from oceanic crust along our profile. While the oceanic crust close to the continent–ocean boundary is just 3.5–5 km thick, itsthickness increases northwards towards the Southern Kerguelen Plateau to 12 km. This change is accompanied by thickening of a lower crustal layer with high P-wave velocities of up to 7.5 km s–1, marking intrusive rocks emplaced beneath the mid-ocean ridge under increasing influence of the Kerguelen plume. Joint interpretations of our crustal model, seismic reflection data and magnetic data sets constrain the age and extent of oceanic crust in the research area.Oceanic crust is shown to continue to around 160 km farther south than has been interpreted in previous data, with profound implications for plate kinematic models of the region. Finally, by combining our findings with a regional magnetic data compilation and regional seismic reflection data we propose a larger extent of oceanic crust in the Enderby Basin than previously known.

AB - Seismic reflection and refraction data were collected in 2007 and 2012 to reveal the crustal fabric on a single long composite profile offshore Prydz Bay, East Antarctica. A P-wave velocity model provides insights on the crustal fabric, and a gravity-constrained density model is used to describe the crustal and mantle structure. The models show that a 230-kmwide continent–ocean transition separates stretched continental from oceanic crust along our profile. While the oceanic crust close to the continent–ocean boundary is just 3.5–5 km thick, itsthickness increases northwards towards the Southern Kerguelen Plateau to 12 km. This change is accompanied by thickening of a lower crustal layer with high P-wave velocities of up to 7.5 km s–1, marking intrusive rocks emplaced beneath the mid-ocean ridge under increasing influence of the Kerguelen plume. Joint interpretations of our crustal model, seismic reflection data and magnetic data sets constrain the age and extent of oceanic crust in the research area.Oceanic crust is shown to continue to around 160 km farther south than has been interpreted in previous data, with profound implications for plate kinematic models of the region. Finally, by combining our findings with a regional magnetic data compilation and regional seismic reflection data we propose a larger extent of oceanic crust in the Enderby Basin than previously known.

KW - антарктика

KW - океанический спрединг

KW - земная кора

KW - ГЕОФИЗИКА МОРСКАЯ

KW - Composition and structure of the oceanic crust

KW - Antarctica

KW - Crustal structure

UR - https://pure.spbu.ru/admin/files/100912848/Altenbernd_et_al._2022.pdf

UR - https://academic.oup.com/gji/article/231/3/1959/6674762

M3 - Article

VL - 231

SP - 1959

EP - 1981

JO - Geophysical Journal International

JF - Geophysical Journal International

SN - 0956-540X

IS - 3

ER -