DOI: 10.1016/j.jag.2014.01.013
Scopus记录号: 2-s2.0-84924374147
论文题名: Exploration of tectonic structures with GOCE in Africa and across-continents
作者: Braitenberg C
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2015
卷: 35, 期: PA 起始页码: 88
结束页码: 95
语种: 英语
英文关键词: Macrogeologic lineaments
; Mineral exploration
; Satellite GOCE
; Suture mapping
英文摘要: The gravity anomaly field over the whole Earth obtained by the GOCE satellite is a revolutionary tool to reveal geologic information on a continental scale for the large areas where conventional gravity mea-surements have yet to be made. It is, however, necessary to isolate the near-surface geologic signal from the contributions of thickness variations in the crust and lithosphere and the isostatic compensation of surface relief. Here Africa is studied with particular emphasis on selected geological features which are expected to appear as density inhomogeneities. These include cratons and fold belts in the Precam-brian basement, the overlying sedimentary basins and magmatism, as well as the continental margins. Regression analysis between gravity and topography shows coefficients that are consistently positive forthe free air gravity anomaly and negative for the Bouguer gravity anomaly. The error and scatter on the regression are smallest in oceanic areas, where it is a possible tool for identifying changes in crustal type. The regression analysis allows the large gradient in the Bouguer anomaly signal across continental margins to be removed. After subtracting the predicted effect of known topography from the original Bouguer anomaly field, the residual field shows a continent-wide pattern of anomalies that could be attributed toregional geological structures. A few of these are highlighted, such as those representing Karoo magmatism, the Kibalian foldbelt, the Zimbabwe Craton, the Cameroon and Tibesti volcanic deposits, the Benue Trough and the Luangwa Rift. A reconstruction of the pre-break up position of Africa and South America (the plates forming West Gondwana) is made for the residual GOCE gravity field. The reconstruction allows the positive and negative anomalies to be compared across the continental fragments, and sohelps identify common geologic units that extend across both the now-separate continents. © 2014 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79579
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Mathematics and Geosciences, University of Trieste, Trieste, Italy
Recommended Citation:
Braitenberg C. Exploration of tectonic structures with GOCE in Africa and across-continents[J]. International Journal of Applied Earth Observation and Geoinformation,2015-01-01,35(PA)