1 INTRODUCTION

The 4th International Geoscience Symposium (4th IGS) was held at Kyushu University, Fukuoka on March 4th–6th 2017, followed by a 7 days field trip of Kyushu Island and Satsuma Iwo Jima island. The IGS was organized by ‘Project A research group’, which focuses on early Earth history (main organizer was S. Kiyokawa, T. Ito, M. Ikehara, and K.E. Yamaguchi), and have taken place every 3–4 years; The 1st IGS took place in 2008 at Kyushu University and Kitakyushu National Science Museum, Fukuoka. The 2nd IGS was in 2011 at National Taiwan University, Taiwan and the 3rd IGS was in 2014 at KIGAMU, Korea. The title of the 4th IGS was ‘Precambrian World 2’. It mainly focused on Earth system science in the Precambrian, but also featured studies of the Phanerozoic, recent environmental change, and the modern Earth system.

During the Precambrian World 2, a total of 28 oral talks were given, including 5 key note talks (40 min), and 7 invited talks (20 min). Thirty‐three posters were presented during a dedicated poster session. Five keynote speakers, J. Kirschvink (CALTEC: USA), A. Hofmann (University of Johannesburg: South Africa), C. Rosiere (UFMG: Brazil), W. Bleeker (Geological Survey of Canada: Canada), A. Lelpi (Royal Museum for Central Africa: Belgium), and F. Inagaki (JAMSTEC: Japan) provided insights into breakthrough and new theories of Earth's history. Many other talks and posters also represented innovative findings and suggestive ideas for understanding Earth's history. A total of 151 people including 40 non‐Japanese scientists, 35 Japanese scientists, 40 students, and several representatives from industry joined this meeting.

Topics covered many geoscience disciplines, Stratigraphy, Sedimentology, Structural geology, Geochemistry, Age dating, Paleo‐oceanography, Microbiology, Marine and Resource Geology, which were performed in various regions, such as Canada, USA, Brazil, South Africa, Ghana, Congo, Egypt, Australia, Antarctica, Japan and modern ocean (Pacific, Sea of Japan, Southern Atlantic Ocean, Bering sea, Izu Bonin island, Japan Trench and Nankai Trough etc.). A post conference field trip investigated a transect of Kyushu island to Satsuma Iwo‐Jima island during March 6–10th. It included the Nippon Steel ironworks, Hiraodai Mitsubishi Material limestone quarry, Taioh Gold mine, Aso Caldera‐Mountain, Japan Limonite mine, Sakurajima, Aira caldera and Satsuma Iwo‐Jima island.

This symposium was supported by Kyushu University, JSPS, GSJ, Mishmi Village, JAMSTEC, Nippon Steel, Mitsubishi Material, Windy Network, Kyuhel Co., Aso Volcano Museum, Taioh Gold Mine, Japan Limonite and Fukuoka Convention and Visitors Bureau. We are pleased to publish some selected researches from 4th IGS ‘Precambrian World 2’ in a special issue of Island Arc (this volume).