Herry, Urutan sedimen dan bentuk/evolusi cekungan2 di sekeliling Sundaland ini (NSB, CSB, SSB, Sunda/Asri, West Java, East Java, Barito, South Sulawesi, dan Natuna) kalau kita lihat memang menunjukkan karakter yang sama dari pre-, syn-, post-rift, dan sagging sequence-nya. Hanya, saat inisiasinya berbeda. Cekungan2 yang ada di timur Sundaland lebih dulu mulainya (lebih tua). Pre-rift adalah umumnya basement cekungan2 ini yang isinya bisa batuan beku atau sedimen yang umumnya sudah termetamorfosakan. Syn-rift sediments-nya adalah umumnya endapan2 non-marin, shallow lakustrin atau deep lakustrin misalnya : Lower Tanjung, Salo Kalupang, Malawa, Ngimbang, Banuwati, Kikim, Jatibarang, Pematang, Lama, Bruksah, Banuwati, Lower Talang Akar, Lower Gabus. Post-riftnya : Keras, Menggala, Bampo, Upper Tanjung, Upper Talang Akar, Upper Gabus, Barat, Bekasap, Berai. Sagging-nya umumnya endapan karbonat seperti Baturaja, Berai, Cibulakan, Kujung, Tonasa, dan formasi dominan serpih seperti Baong, Gumai, Telisa, dan Tuban. Itu hanya gambaran regional, detail-nya bergeser2 sedikit antara formasi dan sekuen rifting-saggingnya. salam, awang Herry Maulana <[EMAIL PROTECTED]> wrote: Pak Awang,
Apa syn-rifts yg ada di Sundaland, dan proto SCS, mempunyai karakteristik yang sama satu dengan yg lain, artinya mulai dari pre-, syn- dan post-rift serta sag phase? Herry Awang Satyana wrote: Wah saya tak bilang syn-rift tak bisa marin. Coba deh diperjelas dulu definisi syn-rft yang jadi diskusi ini, sebab syn rift itu tak hanya syn-rift as a whole, ia juga punya banyak stages-nya seperti peri-graben, inferior, dst sampai ke late syn-rift yang memang marin menjelang post-rift dan sagging. Saya hanya menyoroti bahwa itu non-marine untuk early stages of syn-rift. Saya pikir Christ Morley banyak menganalogikan soal syn-rift nya dari beberapa penelitian lapangannya di East African Rift System. Coba cek di AAPG Bull. Dan, jangan lupa mengaitkannya ke sejarah termal mantel di bawahnya, sebab rifting hanya ekspresi di crust, ada domain termal yang mengendalikannya di bawah sana. salam, awang Rovicky Dwi Putrohari wrote: Marine syn-rift why not ? Hydrocarbons in rift basins: the role of stratigraphy By Joseph J. Lambiase and Christopher K. Morley yg diterbitkan Royal Society. Menyebutkan ada kemungkinan juga bahwa syn-rift terisi oleh marine sedimen. Namun dalam jumlah minyak yg dihasilkan oleh source rock synrift sesuai statistic yg dibuat oleh Morley, (1999), hanya 1 % yg berupa simple syn-rift marine, 1% untuk marine synrift and pasive margin, namun 53% untuk marine synrift and sag. === quote The distribution of the reserves is skewed very heavily towards rifts that have a sag basin associated with them; ca. 88% of all the reserves, or 1:79 1011 barrels, occur in rifts with sag basins (figure 13). Marine syn-rift and sag basins account for approximately 1:06 1011 barrels, or 53% of the total, while 4:8 1010 barrels, or 24%, occur in non-marine syn-rift and sag basins and 13% (2:5 1010 barrels) in non-marine syn-rift and marine sag basins. Surprisingly, marine simple rifts account for only 1% or 2 109 barrels. == end quote Pasti deh kepingin papernya :) aku cuplik abstractnya saja ya dibawah sana ... RDP ============================== Hydrocarbons in rift basins: the role of stratigraphy J. J. Lambiase, C. K. Morley Abstract: Hydrocarbon occurrence and distribution in rift basins is largely a product of the stratigraphic succession in the syn- and post-rift phases of basin evolution. Most of the known reserves of recoverable hydrocarbons occur in rifts with post-rift sag basins and in those basins that are dominated by marine fill. Simple rifts and passive margins are significantly less prolific. Key factors are the style of post-rift tectonics and whether the basin fill is dominated by non-marine or marine strata. Tectonically derived topography is the prime control on both sedimentary processes and facies distribution, which results in a consistent geographical and stratigraphic distribution of hydrocarbon source rocks, reservoirs and seals in syn-rift successions. Potential reservoirs are abundant throughout the syn- and post-rift successions and include a wide variety of sandstone and, less commonly, carbonates. Source rocks occur less frequently and are restricted to specific stratigraphic horizons; their presence or absence is one of the limiting factors in hydrocarbon distribution. Good seals tend to be uncommon in continental syn-rift successions and their absence often prevents the formation of hydrocarbon accumulations. Seals are more common in post-rift successions and widespread in marine syn-rift successions. The reserve distribution is largely controlled by seal distribution, which is best in sag-basin successions and in basins filled with marine strata. A strategy for the efficient exploration of rift basins can be derived from post-rift basin geometry and the nature of the stratigraphic fill. Plays can be developed that identify the most prospective areas within the syn- and post-rift successions by predicting the distribution of hydrocarbon source rocks, reservoirs and seals from stratigraphic architecture. -- http://rovicky.blogspot.com --Writer need 10 steps faster than readeR -- --------------------------------------------------------------------- To unsubscribe, send email to: iagi-net-unsubscribe[at]iagi.or.id To subscribe, send email to: iagi-net-subscribe[at]iagi.or.id Visit IAGI Website: http://iagi.or.id IAGI-net Archive 1: http://www.mail-archive.com/iagi-net%40iagi.or.id/ IAGI-net Archive 2: http://groups.yahoo.com/group/iagi Komisi Sedimentologi (FOSI) : Ratna Asharina (Ratna.Asharina[at]santos.com)-http://fosi.iagi.or.id Komisi SDM/Pendidikan : Edy Sunardi(sunardi[at]melsa.net.id) Komisi Karst : Hanang Samodra(hanang[at]grdc.dpe.go.id) Komisi Sertifikasi : M. 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