Showing papers by "Ake Fagereng published in 2013"
TL;DR: In this article, the Coulomb stress transfer in this sequence is calculated, and found to be consistent with segmented slip on a fault system synthetic to a nearby border fault and restricted to depths < 12 km.
45 citations
TL;DR: In this paper, the Chrystalls Beach Complex, New Zealand, comprises phacoids formed from dismembered beds by layer-parallel extension, enclosed within a relatively incompetent matrix, and the local stress and strain conditions experienced within a mixed rheology shear zone undergoing volume loss and deformation approximating simple shear.
34 citations
TL;DR: The subvertical Kuckaus Mylonite Zone (KMZ) is a km-wide, crustal-scale, Proterozoic, dextral strike-slip shear zone in the Aus granulite terrain, SW Namibia as discussed by the authors.
30 citations
Journal Article•
TL;DR: The research endeavour is presently bedevilled by political manoeuvring among groups with divergent interests that too often have little to do with science, while past and present contributors of research are excluded from discussions that aim to formulate research strategy as discussed by the authors.
Abstract: South Africa has a long track record in Southern Ocean and Antarctic research and has recently invested considerable funds in acquiring new infrastructure for ongoing support of this research. This infrastructure includes a new base at Marion Island and a purpose-built ice capable research vessel, which greatly expand research opportunities. Despite this investment, South Africa's standing as a participant in this critical field is threatened by confusion, lack of funding, lack of consultation and lack of transparency. The research endeavour is presently bedevilled by political manoeuvring among groups with divergent interests that too often have little to do with science, while past and present contributors of research are excluded from discussions that aim to formulate research strategy. This state of affairs is detrimental to the country's aims of developing a leadership role in climate change and Antarctic research and squanders both financial and human capital.
20 citations
TL;DR: The research endeavour is presently bedevilled by political manoeuvring among groups with divergent interests that too often have little to do with science, while past and present contributors are excluded from discussions that aim to formulate research strategy.
Abstract: South Africa has a long track record in Southern Ocean and Antarctic research and has recently invested considerable funds in acquiring new infrastructure for ongoing support of this research. This infrastructure includes a new base at Marion Island and a purpose-built ice capable research vessel, which greatly expand research opportunities. Despite this investment, South Africa’s standing as a participant in this critical field is threatened by confusion, lack of funding, lack of consultation and lack of transparency. The research endeavour is presently bedevilled by political manoeuvring among groups with divergent interests that too often have little to do with science, while past and present contributors of research are excluded from discussions that aim to formulate research strategy. This state of affairs is detrimental to the country’s aims of developing a leadership role in climate change and Antarctic research and squanders both financial and human capital.
19 citations
TL;DR: In this article, the major element composition, δ18O and δD values, and water content of impact-related granophyre, and pseudotachylite, from various Vredefort Dome localities, were determined, aiming to constrain the mechanism of melt formation and the relationship between pseudotACHylite and granophyres.
Abstract: We have determined the major element composition, δ18O and δD values, and water content of impact-related granophyre, and pseudotachylite, from various Vredefort Dome localities, aiming to constrain the mechanism of melt formation and the relationship between pseudotachylite and granophyre. The granitoid gneisses and the pseudotachylites they host have almost identical average δD and δ18O values (−67 and 8.6‰, and −67 and 8.4‰, respectively). The water contents of the pseudotachylites are extremely low, consistent with the isolation of the pseudotachylites from free water during and since their formation. There is a bimodal distribution of water content in pseudotachylites, with one group averaging 0.28 ± 0.03 weight % (n = 9) and the other 0.59 ± 0.06 weight % (n = 9). The Vredefort granophyre, which has been interpreted as the pooled product of impact melting, has average δD and δ18O values of −69‰ and 7.6‰, respectively (n = 2) and also has a very low water content (0.23 weight %). Differences in major element and O-isotope composition between the granophyre and the pseudotachylites are not consistent with a simple relationship, but can be explained by a higher component of greenstone in the granophyre. A strong correlation between host and pseudotachylite δ18O values is consistent with a system where the melt composition is controlled by the immediate surroundings. The pseudotachylites with higher water content have slightly higher δ18O values (9.1 compared to 8.1‰). This is opposite to the relationship predicted if water content is related to the proportion of biotite entering the melt. It is possible, instead, that this relates to the incorporation of higher proportions of material altered at low temperature in the high-water group.
12 citations