HIMPUNAN AHLI GEOFISIKA INDONESIA (HAGI) INDONESIAN ASSOCIATION OF GEOPHYSICISTS GEOLOGICAL FIELDTRIP

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1 HIMPUNAN AHLI GEOFISIKA INDONESIA (HAGI) INDONESIAN ASSOCIATION OF GEOPHYSICISTS GEOLOGICAL FIELDTRIP STROMATOLITES OF THE SATONDA ISLAND CRATER LAKE, NORTH SUMBAWA : MODERN ANALOGUE FOR PETROLEUM OPPORTUNITIES OF PRE CAMBRIAN AND EARLY PALEOZOIC REEFS IN INDONESIA (JAKARTA LOMBOK SUMBAWA LOMBOK JAKARTA) 1 4 DECEMBER 2011 INSTRUCTOR : AWANG HARUN SATYANA (BPMIGAS)

2 Location of the Satonda Island, northwest offshore of Tambora volcano, North Sumbawa. Dotted line shows the travel route to reach the island by chartered bus and yacht. Google map showing the location of the Satonda Island, northwest offshore of foot of Tambora volcano.

3 OVERVIEW OF THE FIELDTRIP Satonda is a small remnant volcanic island, south of the Flores Sea, north of Sumbawa and northwest of Tambora volcano, with a unique habitat a crater lake filled with seawater. Because the lake has lost all direct connections with the open Flores Sea, the lake water has acquired higher alkalinity, ph and carbonate mineral saturation than the surrounding seawater. Such conditions are apparently hostile for most marine macrobiota, which were therefore excluded from the lake. Instead, we find calcareous reef like structures composed of red algae, serpulids, foraminifera and mats of in situ calcifying microbe of cyanobacteria. The macro and micro structures of these deposits are similar to certain types of microbialites (i.e. deposits formed by the permineralization of microbial mats) known as stromatolites, which were once particularly widespread on Earth in the late Pre Cambrian and Early Paleozoic oceans. The fieldtrip to the Satonda Island will observe the modern stromatolites outcropping at the rim of the Satonda Lake, assessing their sedimentology and possible reservoir qualities for petroleum. There will be opportunities to do snorkeling at the lake to see living stromatolites at depth. Snorkeling will also be conducted at the shore of the opening Flores Sea, just outside of the Satonda Lake, to see the significant differences on marine biota and oceanographic setting between the isolated Satonda Lake and open Flores Sea. Returning to the Sumbawa Island, we will drop by at the coastal cliff of foot of Tambora volcano made by pyroclastics bursted out from world famous 1815 s paroxysmal Tambora eruption. The fieldtrip will combine field observation and classroom to discuss the petroleum potential of stromatolitic reefs in Pre Cambrian and Early Paleozoic geology of Indonesia. Pre Cambrian stromatolites in the Middle East and Silurian stromatolites in Canada are known to contain oils. Some areas in Eastern Indonesia have potential to have similar kind of stromatolites and could be significant targets in the future. Their modern analogues forming and outcropping in the Satonda Lake provide the only single place in Indonesia to study them. The Satonda Island crater lake is, therefore, a very important field laboratory for geology and life evolution. Diving into the lake may be described as a time tunnel traveling to the Pre Cambrian and Early Paleozoic Earth. Typical concentric lamination of stromatolites, Satonda Lake, forming inter laminating porosities. The materials are aragonitic and easy to dissolve forming secondary porosities.

4 Underwater camera showing contrasting view of dull coloured oceanographic setting with single marine biota of stromatolites in the Satonda Lake (left) and bright coloured oceanographic setting with various marine biota of coral reefs and fish at the shore of open Flores Sea (right). Diving into the Satonda Lake like time tunnel traveling into the primitive Earth when stromatolites predominated all structures in the early Earth s oceans. TENTATIVE FIELDTRIP ITINERARY Thursday 1 December 2011 Air travel (morning) by Garuda from Jakarta to Ampenan Mataram, Lombok Briefing for fieldtrip Land travel by chartered bus from Mataram to Kayangan Harbour Sea travel by public ferry crossing the Alas Strait to Pototano Harbour, Sumbawa Land travel by chartered bus from Pototano to Sumbawa Besar Stay in a hotel, Sumbawa Besar Friday 2 December 2011 Sea travel by chartered yacht crossing the Saleh Bay to Satonda Island Briefing for fieldtrip in yacht Geological observation and snorkeling in Satonda Island and Satonda Lake Snorkeling at Satonda Lake and shore of the Flores Sea Sea travel by chartered yacht along the shore of North Sumbawa (Flores Sea) to Pantai Kenanga Geological observation at the coastal cliff made by pyroclastics of paroxysmal 1815 Tambora eruption Sea travel by chartered yacht returning to the hotel in Sumbawa Besar Classroom discussion

5 Saturday 3 December 2011 Land travel by chartered bus from Sumbawa Besar to Pototano Harbour Sea travel by public ferry crossing the Alas Strait to Kayangan Harbour, Lombok Stop at Sampoerna Cliff observing pyroclastics of Rinjani eruption deposited into submarine shallow sea associated with coral reefs Land travel to Senggigi Beach, stop by at sightseeing spots (Karangasem Palace at Narmada or shopping market) Stay at a hotel, Senggigi Beach Cultural night (local art show) Sunday 4 December 2011 Free time in the whole morning at Senggigi Beach Air travel (afternoon) by Garuda from Mataram to Jakarta Arrive at Jakarta, end of the fieldtrip ABOUT THE INSTRUCTOR Awang Harun Satyana is a Sr. Manager Exploration Assessment and Resource Management of BPMIGAS (Government of Indonesia Executive Body for Upstream Oil and Gas Business). He graduated from the Geology Department of the University of Padjadjaran, Bandung in He has been working for oil industry for 22 years. He worked for PERTAMINA from , assigning various positions as Exploration Geologist and Regional Geologist. In 2002, Awang joined BPMIGAS, and has assigned various technical and managerial positions. Awang has strongly maintained his technical capabilities by actively servicing international and national geoscience societies by contributing papers, articles, keynote talks, guest lectures, fieldtrip guide and courses. There have been totally 235 publications he made (76 full papers for conferences, 33 articles for journals, 98 invited presentations, keynotes, guest lectures, fieldtrip guide, 22 course manuals, 6 chapters in six books). Several of his papers earned awards as the best papers and presentations. As appreciation for his great contribution and dedication to geosciences, Lasut Award from IAGI and "HAGI Award" from HAGI was awarded to Awang in 2002 and 2008, respectively. Awang was also the first Indonesian geologist assigned by the AAPG (American Association of Petroleum Geologists) as the Associate Editor of the AAPG Bulletin (during ). Awang is an active member of IAGI (Indonesian Association of Geologists), IPA (Indonesian Petroleum Association), AAPG, HAGI (Indonesian Association of Geophysicists), and GSA (Geological Society of America). Awang also actively have serviced as the fieldtrip leader bringing geologists and non geologists to many areas in Indonesia from Sumatra to Papua to observe and learn geology from field outcrops with various subjects from basic geology to specialized geology such as petroleum geology, tectonics, carbonate sedimentology, or volcanology. On Satonda phenomena, Awang has published several papers in national and international conferences.