Timing: Fieldtrip was held from November 16-18 November, 2017. Location: Company Visit to PT Bumi Suksesindo, Banyuwangi, Jawa Timur, Indonesia: Site Tujuh Bukit Gold Mine to observe gold exploration and production processes in high sulfidation epithermal system. Trip to Ijen Crater, Banyuwangi, Jawa Timur, Indonesia to observe volcanism processes related to mineralization in high sulfidation epithermal system. Participants The participants of the trips were coming from SEG UGM-SC active members and faculty advisor and also professionals from industry. Sponsors The fieldtrip was funded by SEG Stewart R. Wallace Fund. But to cover all of the costs we needed extra money which come from sponsors. The sponsors for this trip were coming from several mining companies, they are: 1. PT Intan Angkasa Air Service 2. PT SGS Indo Assay Laboratories 3. PT Maxidrill Indonesia 4. PT Namsuma Luban Abadi (Sumacorp) 5. PT J Resources 6. PT Eksplorasi Nusa Jaya 7. PT Indodrill 8. PT Bumi Suksesindo The sponsor is also coming from Steward R. Wallace Fund in the second application round of 2017. The funds were used to sponsor 6 students from SEG UGM-SC, they are: 1. Cendi Diar P. 2. Nurul Arusal 3. Adinda R. H 4. Ivy Nur Arini 5. Amanda Ayu 6. Iza Zulfana F.
Detailed Report Day 1 Participants gathered at southern hall of Grha Sabha Pramana UGM before going to location. The first route is Pulau Merah, near Tujuh Bukit Gold Mine. It takes at least 18 hours from Yogyakarta. Tujuh Bukit is one of the porphyry Cu-Au deposit in Banyuwangi Region, East Java. Tujuh Bukit project is carried under the authority of PT Bumi Suksesindo, which is now reaching the stage of mine development. This world class deposit is holding a 1.9 Bt ore resource with the average grade of 0.45% Cu 0.7 g/t Au, and 93 g/t Mo. Besides, this deposit also comprises Supergene Oxide Gold related with high sulfidation system, measured up to 90 Mt JORC ore resource with the average grade of 0.73 g/t Au and 25.7 g/t Ag. Based on these phenomenal and varied gold deposit type, Tujuh Bukit is one of the most destined field for understanding precious metal exploration and production. Day 2 Company visit to PT Bumi Suksesindo, Banyuwangi. The visit is destined to the mine pit of PT Bumi Suksesindo to observe the outcrop and mining activity, continued to the coreshed area to study the rock type and mineralization as the exploration target. During this company visit, participants attended the presentation about exploration and production processes that were given by mining geologist from the company. After that, participant continued to visit mining pit (Pit B) in western and eastern side, and then they observed ore processing plant. After lunch break, participants were allowed to see the gold processing. The last destination is Pulau Merah Beach to take a coreshed exploration. Trip was continued to Licin area, near Ijen Crater and stay overnight.
Figure 1. Participant visited pit B at Tujuh Bukit gold mine site Figure 2. Participant took a photo at Pulau Merah Beach Day 3 To the north of Tujuh Bukit, there is an active stratovocano which located in the border of Banyuwangi and Bondowoso Region. At the peak of the volcano, measured 2,443 meter above mean sea level, is one of the most well-known crater in East Java named Kawah Ijen which is now activated for geotourism destination. Kawah Ijen is a crater lake which filled with acidic water. During dawn, the lakeside can glisten a blue fire phenomena which is resulted from the combustion of sulphuric gas. Participants tracked towards Ijen s Peak at early morning to see blue fire phenomena on top of the mountain. But unfortunately, the blue fire didn t appear because trip to peak of Ijen Crater took a few hours. Mr. Lucas Donny, as
trip leader, give an explanation about mineralization in Ijen Crater and its relation to high sulphidation epithermal system. Figure 3. Fieldtrip day 3 at Ijen Crater