The Central Mozambique continental margin : Its tectonic evolution as the centrepiece of the initial Gondwana break-up

• Main Author: Müller, Christian Olaf
• Other Authors: Jokat, Wilfried, Spiegel, Cornelia
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universität Bremen 2017
• Subjects: Beira High; Central Mozambique; Africa-Antarctica Corridor; Gondwana break-up; continental fragment; wide-angle seismic data; gravity data; magnetic data; FD amplitude modelling; plate reconstruction; 550; 550 Earth sciences and geology; ddc:550; East Antarctica; Antarc*; Antarctica
• Online Access: https://media.suub.uni-bremen.de/handle/elib/1270; https://nbn-resolving.org/urn:nbn:de:gbv:46-00106035-13

A consolidated knowledge of the formation and dispersal of the former supercontinents reveals important evidence for the eartha s climate and biosphere in the past and contribute to the prediction of their future evolution. Nowadays, a main objective is the investigation of the initial break-up of the continental assembly of Gondwana that serves as a constraint for its subsequent dispersal and the evolution of all oceans and seas in the southern hemisphere. Evidence of the early rifting stages are expected at the margins of Southeast Africa and East Antarctica, whereas the latter one is difficult to access, due to its remote position and ice coverage. To understand the driving forces and the chronology of the break-up and of the massive volcanism additional detailed knowledge of the crustal setting along the margins of Southeast Africa is required. Therefor, a new geophysical dataset was acquired with the RV Sonne in the northern Mozambique Basin at the beginning of year 2014. This comprises a deep seismic sounding profile across a so-far unknown structural high, the Beira High. Additional gravity and magnetic data were systematically recorded across the entire northern Mozambique Basin. Based on velocity, amplitude, density and magnetic modelling, a geological model of the continental margin of Central Mozambique was prepared. A new compilation of all available magnetic data in the Mozambique Basin reveals information about the age of the sea floor, which serves as constraint for the reconstruction of the initial Gondwana break-up. The study depicts a continental origin of up to 23 km thick and partly highly intruded crust at Beira High. In the adjacent coastal areas of the south-western part of Central Mozambique, 7 km thin crust is observed, which is covered by more than 11 km thick sediments and implies the continuation of the continent-ocean transition towards onshore Mozambique. This is in clear contrast to the narrow transition observed in the north-eastern part of the margin and reveals a clear ...