The theme of the Seventh International Dyke Conference (IDC7) is ‘Dyke Swarms: Keys to Paleogeographic Reconstruction’. It will concentrate on mafic dyke swarms and related igneous associations, e.g., sills, kimberlites, syenites, carbonatites, volcanics, etc., with a special emphasis on paleogeographic reconstruction based on geological comparison and paleomagnetic studies. The IDC7 continues the every-five-year tradition started in Toronto, Canada in 1985 by Prof. Henry C. Halls ( University of Toronto). Subsequent IDCs were held in Australia (1990), Israel (1995), South Africa (2001), Finland (2005), and India (2010). The aim of this First Circular is to spread information such as date and place of the conference, to ask advice on the topics, pre- and post-conference field trips, key events including social events, to seek financial support and advertisement intentions. A Second Circular, with detailed information, especially the registration details will be distributed in early of 2016. And finally, a Third Circular, with all the Scientific Program and last-minute practical details, will be posted a couple of weeks before the conference.