The forum was founded in 1995 as the Indonesian Sedimentologists Forum (FOSI). This organization is a communication and discussion forum for geologists, especially for those who deal with sedimentology and sedimentary geology in Indonesia. The forum was accepted as the sedimentological commission of the Indonesian Association of Geologists (IAGI) in 1996. FOSI currently has around more than 1000 members by 2024, including industrial and academic fellows as well as students.

FOSI has close international relations with the Society of Sedimentary Geology (SEPM) and the International Association of Sedimentologists (IAS). Fellowship is open to those holding a recognized degree in geology or a cognate subject, non-graduates who have at least two years relevant experience, and anyone interested in sedimentology.


The intention to found FOSI began when Prof. Yahdi Zaim attended the Regional Meeting of the International Association of Sedimentologists (IAS) in Leuven, Belgium in 1986. The conference showcased remarkable advancements in sedimentology, particularly towards quantitative sedimentology. Many presentations highlighted the quantitative aspects of sedimentation processes based on outcrop data, core drilling, as well as numerical simulation and computation results. The event inspires the desire to establish an organization similar to IAS, namely an Association of Sedimentologists in Indonesia.

On November 30, 1989, Prof. Yahdi Zaim wrote “The Necessity of an Association of Indonesian Sedimentologists: A Thought and Proposal.” This writing was entrusted to Prof. R.P. Koesoemadinata to be presented at the Pertemuan Ilmiah Tahunan (Annual Scientific Meeting) IAGI in Yogyakarta, December 1989. However, due to the atmosphere of the PIT, it was not feasible for Prof. Koesoemadinata to present it at the IAGI plenary session at that time. The manuscript was returned. Afterward, along with Herman Darman, they discussed and matured the idea for the establishment of a platform for Indonesian sedimentologists.

On separate occasions, Herman Darman also attended the British Sedimentology Research Group seminar in Aberdeen in 1994. This meeting also inspired the formation of the Indonesian sedimentology association. Finally, in 1995, Prof. Yahdi Zaim and Herman Darman formed the sedimentology organization named FOSI (Forum of Indonesian Sedimentologists).

In essence, the purpose and objective of FOSI’s formation were to establish an organization as a platform, which in this case serves as a forum for Indonesian sedimentologists and other related fields to meet. These meetings are necessary for communication, sharing ideas, concepts, as well as work and research findings in the field of sedimentology to develop sedimentology, particularly, and geology in general, in Indonesia.

The fields within FOSI include: sedimentology in its broadest sense, development of sedimentological methods, sedimentary basin analysis, sediment petrology, sediment geochemistry, stratigraphy (including seismic stratigraphy), subsurface geology, and others. The idea of a platform for Indonesian sedimentologists was also conveyed to IAGI and later FOSI was warmly welcomed as a specialist suborganization.

Berita Sedimentologi (Sedimentology Newsletter)

The conceptual writing regarding the establishment of a platform for Indonesian sedimentologists was subsequently published in the inaugural edition of the Sedimentology News Bulletin, namely Sedimentology News No. 1, February 1996. Following the formation of FOSI in 1995, the initial activity carried out by FOSI was the publication of Sedimentology News, as a printed medium for facilitating communication and exchanging information regarding various aspects related to sedimentology. Initially, Sedimentology News was limited only to “FOSI members.”

At that time, FOSI had no funding whatsoever, yet the enthusiasm to nurture the newly born FOSI remained fervent. Despite the absence of a budget, Sedimentology News was successfully published. Due to the lack of budget, Sedimentology News was not printed by a professional press, but rather through “photocopy duplication” conducted by Herman Darman utilizing facilities in his office at Shell. As a form of appreciation, the Shell logo was displayed in Sedimentology News as a sponsor. Presently, Sedimentology News has experienced rapid development, being able to publish various aspects of sedimentology in Indonesia by Indonesian and foreign researchers and authors. FOSI is also managed very efficiently by its members and executives, involving internationally renowned experts in the field of sedimentology. As of 2020, Sedimentology News has been published in 46 volumes.

Events and Activities

With the publication of Sedimentology News in February 1996, the presence and existence of FOSI as a professional organization in the field of sedimentology under IAGI began to be recognized by the Indonesian geological community. This prompted FOSI’s executives to be motivated to undertake various other activities beyond the publication of Sedimentology News. In December 1996, FOSI participated in the 25th IAGI Congress and Annual Convention held at Hotel Horizon Bandung, where they opened a FOSI booth.

In 1999, FOSI successfully organized a regional seminar with the theme: “Tectonic and Sedimentation of Indonesia,” while also commemorating the 50th anniversary of the publication of the monumental book “The Geology of Indonesia” by R.W. van Bemmelen, first published in 1949 by Martinus Nijhoff, Den Haag. The seminar, held at Sasana Budaya Ganesha ITB, yielded significant outcomes, not only financially but also in terms of FOSI’s increased recognition by the geological and sedimentological communities both domestically and internationally. FOSI received support from KNGMG (Royal Geological and Mining Society of the Netherlands) and successfully brought in international experts in tectonics and sedimentology such as Prof. Robert Hall, Prof. Maruyama, Dr. Henry Possamentier, and Rob Hulsbos, who also represented KNGMG.

Following the successful organization of the international seminar commemorating the 50th anniversary of R.W. van Bemmelen’s book, in 2001, FOSI again successfully organized a regional seminar with the theme “Deep Water Sedimentation” at Hotel Mulia, Jakarta. In 2018, FOSI organized its 3rd Regional Seminar in Yogyakarta, in collaboration with IAS and SEPM. This seminar featured keynote speakers from Malaysia, Indonesia, Taiwan, the USA, the UK, Japan, India, and Australia.