Lecture 5 - Geology of SEA and Philippines PDF

®@@il@@W @~ IB@@~DiJ ~@ 0 ~ fl@ @1ru@J Olm@ IP!m□ilO[?)[?)□ 1ru@ il il@1ru@J PACIFIC PLATE 7 IND AUSTRA IAN PLAtE 75W llOC(O' 105o00' Regional Geology 3 plates were surrounding the Philippines peror amounts Midway illion Years Tuamotu r:,•. Group • I) Austral - ., Pitcairn Island Group...

®@@il@@W @~ IB@@~DiJ ~@ 0 ~ fl@ @1ru@J Olm@ IP!m□ilO[?)[?)□ 1ru@ il il@1ru@J PACIFIC PLATE 7 IND AUSTRA IAN PLAtE 75W llOC(O' 105o00' Regional Geology 3 plates were surrounding the Philippines peror amounts Midway illion Years Tuamotu r:,•. Group • I) Austral - ., Pitcairn Island Group (active) l) Macdonald (l Seamou nt (active) PACIFIC PLATE movement: P'ACIFIC PLATE Regional Geology • Southeast Asian Tectonic Region THE PHILIPPINE SEA PLATE Submarine Ridges Ocean Basins West Philippine Basin Other Basins Parece Vela {30MY)- Shikoku (20MY} Palau- Kyushu Ridge Marianas Basin (opened 6MY and still active} lzu- Bonin Ridge East Marianas West Marianas .c.: ' o~~ 0 . •u1NO~N oo 120°E 140° 145° .c.: ' o~~ 0 . •u1NO~N .c.: ' o~~ 0 . •u1NO~N Back-arc basin Magmatic arc Forearc Spreading axis Arccrust ! at' ---~ - -----, -- - ----~ \ftr=-:J•:> ' : --, ... ~-: _ : , .. I .' ' --\\\~~ ---- Oceanic crust - Asthenosphere motions • f 't Convecting Asthenospher1/ Plate motions 1 \, Partial melt diapir \ '-., ,t ~ t '' ' 1 -\~~ - - ~~c."', ' ' e:,f, , , --- ,,,,,,----- JI° ' ' : , ~: ,_',,',, / 200 100 0 .c.: ' o~~ 0 . •u1NO~N .c.: ' o~~ 0 . •u1NO~N .c.: ' o~~ 0 . •u1NO~N .c.: ' o~~ 0 . •u1NO~N .c.: ' o~~ 0 . •u1NO~N .c.: ' o~~ 0 . •u1NO~N South China Sea Celebes Sea Euras.a11 ma1t1lr>al basfl AdN9 sutx,ucUon or Inn- ::;nodElr.1$1.»'1 Ttrus.l z,one (d1151'led ~ ~ lhruJlll'lfl - h ~-el Sinka-slip faun 2s· - t10'E 2cr' 6 aermam Plateau ' 9cm/yr ENE-WSW preading (NWubba in) (32-30 Ma 10' N 10' S . 20'S 100'E E-W preading (Ea t • ubba in) 30-27 Ma O' 1crs 20·s 110'E JOO'E 30"N NE-SW ( ,outh,.ve t ubba in) 26-24 Ma Brias et al ( 1993) suggested that the SCS spreading ceased around 15..5 Ma. (tniddle Miocene) 2:0"N 10"N More recently, however Barchauseo ,& Roeser (2002) hav,e proposed the event occu1Ted so1newhat earlier, ~ 18' 0'5 Ma~ Nlechanis1n for the forrnation of the South China Sea 1 A gree1nent aruong ,geologi ts: Extension within tb.,e South Chit1a continental 1nass of the Eurasian plate Question: What triggered/cau ed the op,e ning of the South ,C hina Sea? India. . Eura ia colli ion (extra ion tectonic ) V . othing to do \\·ith lndia.. Eura ia collision **Hot debate till no,v! Plastiei11e 1nodel Tapponier et lll. (19,82: 1986) South CJ1i11a Sea opened a a ide effect of the extru ion of lndocbina '- ., ' -... ·.._~_IP'-,..,- ' ~ 1: ~ - - 4 N •• - -----C ,,, 7 -r 1,...,,...--:,,,, , , Rangin et al., 1990; PubeHier et aL (2003,) : Trench pull/rollback Contention: difficult to reconcile with a N-S • preading of the scs Rangin et al (1990): Trench pull **Gravity controlled trench-pull rnay be invo~ed to explain the rifting and preading. T he · ubduction along the Sunda Trench n1ay be re pon ib~e for the opening of the proto-SCS (and even Cele be· Sea) and the ubductjon of the protoSCS , outh of Pala,;van n1ay in turn explain the South China Sea opening.;; Pubellier et al.. (2003): Trench rollback (back-arc ba in rnode O Key que tion: When exactly did India and E ura ia collide? Timi11g of colli ion and opening of SCS Thought to ponder:· 1) How is jt po ible for the Scarborough earnount (al o cal1ed the Scarborough Ridge) the rnai □ preading center ( now jnactive) of the South China Sea, to ubduct beneath the Manila Trench? 211 Scarborough Key feature: -S preading (E-W orientation of the Scarborough) Sean1ount) v . N-S trend of the I\1anila trench 10 - 2) What effect the ubduction of the Scarborough Ridge would have on the tectonic of the Philippine arc? Bonham Ri~III Plateau 9cmlyr - CelebH Si!ra .R. Wi1111 Philippine Burn Benha Pl3tMU 111"n-~..,......-~-,,.'---< A . . Bloek ~ ",Lr . Sulu ,I. ♦ .R. Wi1111 Philippine Burn Benha Pl3tMU 111"n-~..,......-~-,,.'---< A . . Bloek ~ "',Lr . Sulu ,I. ♦ Regional Geology P.~l l ~ iP.~lir■ll ti O r■ RECONSTRUCTION SO llJffilit EAST ASIA §l!Jma mil a r.izecl ~r.o r.m : R. Ha 11, 1 99 6 50 a Sea l,'I fl. ~ 45 a I 0 35 30 .......... -.. ., ..~ _..... -• l~_.,, ....... • f 25 .., , ....-.... .............. . ........... • . , ......• ,, ----....,. 1 .......' ·: 20 0 ::"-...... ----,;: ~ ----;,' ~ . .,, • ~ - -·,, ' 15 10 0 ~ .... __,,.--> ~ ~ TI 1 ~~ ~~ \ oor# l ~ 1$'> ' \ . . , ,c.._ -,, I <...._ ------,,.. s 0 ~ • '~ ,< ' oo{ ~ ~ --::,.a --,,. -"--"' ~ :-" - • . [ ) ~~ - , J C > • ~ ------___.____~7 - ; ·- - . ,, l ¢> ""'- I D ~ -,. 2;:' \ 0 Fig. 1.18 Lithospheric structure in the Taiwan region showing collision of the Luzon Arc with the Eurasian plate. Original drawing by J. Angelier, 1985 The Philippine Mobile Belt • Collision Zones ► Mindoro-Panay Collision Zone ✓ Miocene i===========-1 -- • • 2 3 • ,.....-, ./ \ . ,,_/_--1---+------4-----'\ / B \ '\ <---t----+-----t--+----+~, • L' -1• ;,, I 2 100 km Fig. 1.20 Lithospheric structure in the Mollucas Sea region, showing the incipient arc-a rc collision between Sangihe (1) and Halmahera (2). From Roeder, 1977 The Philippine Mobile Belt: Geology . Metamorphic Rocks Pre- Cretaceous Metamorphic Rocks of Continental Origin: Caramaoy Schist Halcon Metamorphics Romblon Metamorphics Buruanga Metamorphics Cretaceous Metamorphic Rock of Insular arc Affinity: Basic to Ultra basic in cha racier Do not extend beyond Paleogene Ophiolites and Ophiolitic Belts .. - - ... Magmatic Arcs Complete Ophiolite: Zambales, lsabela, Palawan, Pujada Ancient Arcs Youngest: Mindoro ( Amnay) *Oldest Magmatic Arc: Cebu (Cretaceous) *Early Eocene to Oligocene *Middle Miocene to Late Miocene Tungauan Schist *Miocene to Pliocene This are characterized by high silica and concentrated on the western portion of the Philippines *Plio-Pleistocene PMB affinit y: 1. !locos- Centra l Luzon Basin Active Volcanic Arcs 2. Cagayan Valley Basin 1. Luzon Volcnaic Arc 3. Southern LuzonBicol Basin 2. East- Philippine Volcanic Ar c 4. Mindoro Basin 3. Negros-Panay Arc 4. Sulu- Zamboanga Arc 5. Cotabato Arc 5. lloilo Basin 6. Visayan Sea Basin 7. Sama r Basin 8. Agusan- Davao Basin 9. Cotabato Basin **Palawan is eurasia n affinity SEDIMENTARY BASIN SEDIMENTARY FILL THICKNESS llocos- Central Luzon Basin 8000 m Cagayan Valley Basin 8,100 m Southern Luzon- Bicol Basin 4,600 m Mindoro Basin lloilo Basin 5,000 m Visayan Sea Basin 4,000 m Samar Basin Agusan- Davao Basin 12,000 m Cotabato Basin 8,000 m The Philippine Mobile Belt: Basements Southern Cordillera Range Pugo Formation Central Cordillera Range Lepanto Metavolcanics Northern Cordillera Suyo Schist Cagayan Valley Basin Abuan Formation Central and Eastern Northern Sierra Madre Casiguran Ophiolite Caraballo Range Caraballo Formation Northern Northern Sierra Madre Angat Ophiolite The Philippine Mobile Belt: Basements Zambales Range Zambales Ophiolite Southwest Luzon San Juan Formation - Batangas Halcon Metamorphics - NE Mindoro Mansalay Formation - SW Mindoro Marinduque Formation - Marinduque Gumaca Schist - Bondoc Southeast Luzon Basin Baleno Schist - Masbate Island Danao Schist - Ticao Island Makalawang Limestone - Burias and adiacent Islands The Philippine Mobile Belt: Basements Southeast Luzon Arc Maliguit Formation - Quezon - Camarines Norte Siruma Schist - Caramoan Peninsula Yop Formation - Catanduanes Rapu-rapu Schist - Rapu-rapu Island Panganiran Peridotite - Bicol Peninsula North Palawan Block Bacuit Formation - Northern Palawan Romblon Metamorphic Complex - Romblon South Palawan Block Beaufort Ultramafic Complex - Southern Palawan Panay Island Buruanga Metamophic Complex - Buruanga Antique Ophiolite - Antique Panpanan Formation - Central Panay-lloilo Basin Sibala Formation - Eastern Panay The Philippine Mobile Belt: Basements Negros Basak Formation Cebu Tunlob Schist - Northern/Central Cebu Pandan Formation - Southern Cebu Kanglasog Volcanic Complex - Siquiior Island Bohol Alicia Schist Samar Samar Ophiolite Leyte Malitbog Ophiolite - Western Leyte/Camotes Island Albuera Diorite - Central Highlands Tacloban Diorite - Eastern Leyte Dinagat Group of Islands Nueva Estrella Schist The Philippine Mobile Belt: Basements Sulu Archi ela o Sulu Serpentinite Zamboanga Tangauan Schist - Zamboanga Peninsula Dansalan Metamorphic Complex - North-Central Zamboanga Mangabel Formation - Sibuguey Peninsula Central Mindanao Tago Schist Agusan Davao Basin Adgaoan Formation - Agusan Basin Kabagtican Formation - Davao Basin Tagobo Conglomerate - Davao Gulf-Samal Island Mindanao Pacific Cordillera Dinagat Ophiolite - Northern Pacific Cordillera Baggo Limestone - Central Pacific Cordillera Barcelona Formation - Southern Pacific Cordillera The Philippine Mobile Belt: Basements Da uma Ran e Salbuyan Schist Cota bato Basin Patut Formation Sarangani Peninsula Malita Formation Puiada Block Puiada Ophiolite ' G.R. Virac Island 7 EPOCH AGE HOLOCENE 4 Late PLEISTOCENE ... ! . . Middle · 2 Early w w Late Early PLIOCENE z (!) 0 w •••.3 •• Late -- z MIOCENE •···2•• Middle· ····1·· Early-- 2 Late 28.4 OLIGOCENE Early 33.9 4 w z w (!) 0 w ~ Late 37.2 3 EOCENE ...J •····· Middle 2 48.6 Early 55.8 3 PALEOCENE Late -··-----------· 2 Middle .................................... 1 Early 58,7 61 .7 65.5 (J) :::, 0 w Upper Late 99.6 (.) ~ w 0:: Lower Early (.) 145,5 Upper 3 Late Middle 2 Middle Early 161 .2 175.6 199. Pugo Formatlon/Lepan MeCavolcanlca Philippine Stratigraphy 1111 .. II NORTHERN PALAWAN HOLOCEN E P LEISTOCENE - 4 Late 3 - Middle 2 Earl w z PLIOCENE 2 w Late Early 8 w z •···3·· Late·· MIOCENE ··· ·2·· Middle· Kapoas Granite ····1·· Early-- 20.43 SL Paul l.Jmestone 23.03 2 Late 28.4 OLIGOCENE Early 33.9 4 w w z (!) 0 w EOCENE ..J a: Late 37.2 3 •••••• Middle - 40.4 2 48.6 Early Mayt,guid limestone 3 PALEOCEN E "' ::, 0 Late --------------2 Middle --------------Early Boayan Formation Upper 99.6 CJ "'CJ --------- ------ Late w ~ w 61 .7 65.5 Caramay Schist --- --· -- Early Lower 3 Late 2 Middle Early 3 Late 2 Middle 1 Early 3 Late 2 Middle Col-.,IIOn~ 205 250 Early 290 References Pena, R et. al. 201 0. Geology ol the Philippines Second Edition. Quezon City, Philippines