Direct Mesoproterozoic connection of the Congo and Kalahari cratons in proto-Africa : Strange attractors across supercontinental cycles

Summary, in English

Mobilistic plate-tectonic interpretation of Precambrian orogens requires that two conjoined crustal blocks may derive from distant portions of the globe. Nonetheless, many proposed Precambrian cratonic juxtapositions are broadly similar to those of younger times (socalled "strange attractors"), raising the specter of bias in their construction. We evaluated the possibility that the Congo and Kalahari cratons (Africa) were joined together prior to their amalgamation along the Damara-Lufilian-Zambezi orogen in Cambrian time by studying diabase dikes of the Huila-Epembe swarm and sills in the southern part of the Congo craton in Angola and in Namibia. We present geologic, U-Pb geochronologic, and paleomagnetic evidence showing that these two cratons were directly juxtaposed at ca. 1.1 Ga, but in a slightly modified relative orientation compared to today. Recurring persistence in cratonic connections, with slight variations from one supercontinent to the next, may signify a style of supercontinental transition similar to the northward motion of Gondwana fragments across the Tethys-Indian oceanic tract, reuniting in Eurasia.

• Author: Johanna Salminen; Richard Hanson; David A.D. Evans; Zheng Gong; Tierney Larson; Olivia Walker; Ashley Gumsley; Ulf Söderlund; Richard Ernst
• Department/s: Lithosphere and Biosphere Science
• Publishing year: 2018
• Language: English
• Pages: 1011-1014
• Publication/Series: Geology
• Volume: 46
• Issue: 11
• Links: http://dx.doi.org/10.1130/G45294.1
• Document type: Journal article
• Publisher: Geological Society of America
• Topic: Geology
• Status: Published
• ISBN/ISSN/Other: ISSN: 0091-7613