The fruits – as they say – had finally ripened and what fell off the tree? A paper of course*. A nice fat, juicy paper about those lovely Eocene-age volcanics that lie within the Senakin Peninsula.
After a couple of decades wondering when someone would publish on the basalts and volcaniclastic sediments in Kalimantan Selatan and noting, finally, no one was, we did. However, this would not have happened without the collaboration of several people.
Basalt displaying columnar jointing, Tanjung Formation.
Firstly, there is Mike Friederich. He has worked in SE Asia for yonks and yonks and knows not just the coal, but also the formations, tectonics and structures like the back of the proverbial hand. I’ve more than doubled my age since first meeting Mike and he was there at the beginning of my studies in the mid 1980s.
Then there are my friends and colleagues Hendra Amijaya and Ferian Anggara, both professors at Gadjah Mada University in Yogjakarta. I’ve known these gentlemen less than Mike but still for over 10 years. Without their guidance and knowledge of the local geology, this project would never have succeeded.
Finally, there is Jess Trofimovs from the School of Earth and Atmospheric Sciences at Queensland University of Technology here in Brisbane. Without Jess’ knowledgeable input and patience in explaining the rudimentary basics of volcanics, this paper would have crashed and burned long ago.
An additional thanks, though, must go to Elino Febriadi and his crew at P.T. Arutmin Indonesia. Truly, without his and Arutmin’s support and help for our field trip to collect samples, no work would have gotten done and our understanding of the volcanics would have been where it was in the mid 80s. I hasten to add, however, that Pak Elino and his team always had a deep understanding of the interrelationships of the basalts, volcaniclastic sediments and their relation to the surrounding marine and fresh water sediments. 
They have been drilling them for decades. We are deeply grateful to them for sharing their knowledge freely.
The paper (see link below) is the first of three. The second paper will focus on the geochemistry of the basalts and volcaniclastic sediments and their origins. The third paper will synthesize the first two papers plus what is known about other volcanic rocks in the Tanjung Formation and equivalents elsewhere in Sulawesi and try to make sense of what it all means. Stay tuned.
*Moore, T.A., Friederich, M.C., Trofimovs, J., Anggara, F., Amijaya, D.H., 2020. Syn-sedimentary mafic volcanics in the Eocene coal-bearing Tanjung Formation, Senakin Peninsula, South Kalimantan (Borneo), Indonesia, Indonesian Journal on Geoscience, v. 7, No. 1, 65-85.
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