notes on singapore geology_ppt presentation
TRANSCRIPT
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Content
I) The Geological Formations in Singapore
II) A Brief Description of Formation
III) Stratigraphy3.1.Stratigraphy of the Paleozoic Geology in Singapore (542 – 251 m.y)
3.2.Stratigraphy of the Mesozoic Geology in Singapore (251 – 65 m.y)
3.3.Stratigraphy of the Cenozoic Geology in Singapore (65 m.y- Present)
IV) Tectonic History and Structures
References
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I) The Geological Formations in Singapore
Ten separate formations are recognized in Singapore.
1) Sajahat Formation (S) Lower Paleozoic(Upper Paleozoic/Triassic ?)
2) Gombak Norite (GN) Lower Paleozoic3) The Paleozoic Volcanics (PV) as Same age of (S) 4) Bukit Timah Granite (BT) Lower to Middle Triassic5) The Jurong Formation (Upper Triassic to Lr-Mid Jurassic)6) Fort Canning Boulder Bed FCBB (Late Cretaceous Age)7) The Older Alluvium (late Tertiary to early Mid-Pleistocene)8) The Huat Choe Formation (HC) Early to Mid Plieistocene9) The Tekong Formation (T) Mid Holocenc10) The Kallang formation (K) Late Pleistocene (1.5 m.a) to
PresentMarine Member (Km)Alluvial Member (Ka)Littoral Member (Kl)Transitional Member (Kt)Reef Member (Kr)
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Geography of Singapore (NEA)
Geology of Singapore (NEA)
Data from Geology of Singapore (2009)
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Generalized Cross section of the Central to East of Singapore(Approximate Scale)
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Geology of Singapore (NTU)
195 mKallang Fm.
OLD ALLUVIUM
BUKIT TIMAH GRANITE
0 10 Km
FORT CANNING
BOULDER
Jurong Fm.
Sajahat Fm
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II) A Brief Description of Formation
Paleozoic1. Sajahat Formation (S) Lower Paleozoic (Upper
Paleozoic/Triassic ?)Variable metamorphosed sedimentary rock, quartz, sandstone, and argillite found on Pulau Sajahat and SajahatKachil, north of Pulau Tekong.
2. Gombak Norite (GN) Lower PaleozoicNoritic and gabbroic rock in central Singapore and as part of the Ophiolite suite of the Lr Pz geosyncline. But, it could be younger if GN is interpreted as basic differentiate of Triassic magma.
3. The Paleozoic Volcanics (PV) as Same age of (S)
Partially metamorphosed volcanic agglomerates unit of andesitic fragments, ash and tuff in eastern Singapore, Pulau Tekong.
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II) A Brief Description of Formation Mesozoic
4. Bukit Timah Granite (BT) Lower to Middle TriassicGranite, Granodiorite, Norite, adamalite
The BT was emplaced by two phases that can be grouped Older acid group assumed to be a cooling phase and slightly younger basic group seem cutting the older Acid dykes. Both groups cut older formations.
5. The Jurong Formation (Upper Triassic to Lr-Mid Jurassic)
Sandstone, Silts, Mudstones, conglomerate and Limestone with various metamorphism (Shale, Slate, Marble). It overlies the granite though contact is never seen that can be divided seven facies deposited in terrestrial, transitional and shallow marine.Facies : (Queens Town, Jong, Ayer Chawan,Pandan, Rimau, St.John, Tengah) Volcanics of tuff, spilitic lava, dykes are contemporaneous with the formations.The Murai schist is a product of dynamic metamorphism within the formation found as a zone of well developed cleavage in rocks at Pasir Laba ridge and within Jongfacies.
6. Fort Canning Boulder Bed FCBB (Late Cretaceous Age)(known as S 3, Boulder Clay or Boulder bed)
Small Colluvial deposits of boulders in soil matrix (hard, Silty Clay & weathered rocks derived from the Jurong Fm.) lied on the Juorng Fm. at central districts and downtown of Singapore.It could have probably deposited when the Jurongformation was deposited and deformed during late Triassic to late Tertiary.
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II) A Brief Description of Formation Cenozoic
7. The Older Alluvium (late Tertiary to early Mid-Pleistocene)The OA is composed of Fluvio-Deltaic sediments. The upper section is completely weathered CLAY and Lower section is Silty to Clayey Sand, coarse, angular, poorly lithified, quartzo feldspathic with some layers of pebbles.Block faulting and renewed movement along the pre-existing faults resulted downwarp occurred and trough was back filled with fluvial sediments with some embayment sediments. It lies unconformably on older rock units or in fault contact with them.
8. The Huat Choe Formation (HC) Early to Mid PlieistoceneThe kaolin –rich clay in fault controlled depression formed
as small lacustrine deposits unconformably on the JurongFm.
9. The Tekong Formation (T) Mid HolocencCoastal terrace deposits with marine and littoral area, unconsolidated sand with some cobbles. Its upper surface is lying at elevations ranged (3.6 to 6.5m) above present sea level.
10. The Kallang formation (K) Late Pleistocene (1.5 m.a) to Present
It consists of both marine and terrestrial deposits that is found in onshore incised river valleys, offshore and coastal areas. The Kallang FormationMarine Member (Km)Alluvial Member (Ka)Littoral Member (Kl)Transitional Member (Kt)Reef Member (Kr)
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II) A Brief Description of Formation
10.1. Marine Member (Km)*Dominantly blue grey, clayey Mud, Sandstone, peatUnconsolidated but slightly consolidated beds occur
10.2. Alluvial Member (Ka) *A variable terrestrial sediments ranged from pebbles beds through Sand, muddy Sand and Clayey to Peat. It is usually unconsolidated to consolidated.
F 1 granular Sand, F2 non-granular Silty Clay10.3. Littoral Member (Kl) *
Well sorted unconsolidated beach Sand and near-shore quartz Sand with minor lateritic, shell and lithic fragments, iron-cemented beach rock
10.4. Transitional Member (Kt)
Unconsolidated black to bluish grey estuarine mud, muddy Sand or Sand withsome high organic content and peat layers
10.5. Reef Member (Kr)Coral, unconsolidated calcareous Sand and lesser quartz, ferruginous and lithic sand(*possibly part of other members and Tekong Fm.)
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III) Stratigraphy
In this context, presents with distributions, age, geological setting and occurrences, collected samples on site and core samples, some available cross-sections and developments.
3.1) Stratigraphy of the Paleozoic Geology in Singapore (542 – 251 m.y)
Distribution of Singapore’s Paleozoic Rocks (K.W. Lee, 2010)
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3.1.1 ) The Sajahat Formation and Paleozoic VolcanicsGeological setting of the Sajahat and Paleozoic Volcanic rocks in Singapore (K.W. Lee,2010)
3.1.2) The Gombak NoriteGeological setting of the Gombak Norite in Singapore (K.W. Lee,2010)
Small Basic Intrusions
Roots of BasicIntrusions
Ophiolitics
DoleriteDykes
MicrograniteDykes
NoriticGabbro
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Bukit Gombak Norite in closed view B as later intrusion (courtesy of Dr.Kyi Khin)
B
Granodiorite intruded by Norite (C, drak colour) and Jointed Granodiorite D in Bukit Gombak (courtesy of Dr.Kyi Khin)
D
C
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3.2) Stratigraphy of the Mesozoic Geology in Singapore (251-65 m.y.)
(K.W. Lee, 2010).
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3.2.1) Bukit Timah GraniteBukit Timah Granite and Sakudu Granite rocks in Singapore(K.W. Lee, 2010).
Bukit Timah Hill natural reserve and old Quarry
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Poorly jointed massive Sakudu granite at Pulau U Bin(Courtesy by U Kyaw Htin Khine)
Sakudu_Eastern Granite outcrops showing spheroidalweathering at Pulau Ubin island
Granite from the Bartley & Kim Chuan Road (After Ong, Moe Sein & et al., 2003).
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3.2.2) The Jurong Formation
Facies Distribution of the Jurong Formation in Singapore(k.W. Lee, 2010).
Brecciated Fault plane A and Conglomeratic Sandstone B of Jurong Fm. at Kent Ridge road (Courtesy of Dr.Kyi Khin)
A
B
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Tuffaceous Sandstone A and Jointed, thin bedded Siltstone B of JurongFm. at Kent Ridge road (Courtesy of Dr.Kyi Khin & U Khin Latt)
A
B
Pebbly Gritty Sandstone D with fining upward cycle and med to thick bedded Sst with mud drapes E shown a break of sedimentation of Jurong Fm. at Labradore park (Courtesy of Dr.Kyi Khin & U Khin Latt)
DE
Gritty Sandstone F altered with Sst G and bidirectional X stratification H of Jurong Fm. at Labradore park (Courtesy of Dr.Kyi Khin &U Khin Latt)
F
G
H
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Stratigraphy of the Jurong Formation (After Redding & et al, 1999).
Facies Distribution of the Jurong Formation changes from SW to NE in Singapore (Lee, 2010).
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Locations of the Pandan Limestone in Singapore (K.W. Lee, 2010).
Cross Section along East Jurong Fairway(Chiam et al., 2003)
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Pandan Limestone in Singapore is generally light to dark grey, yellowish to Brownish with purplish stains (Chiam et al., 2003).
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Basin development of the Jurong Formation (After Redding & et al, 1999).
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Fort Canning Boulder Bed underlying the Jurong Fm.At along the Fort Canning Rise Depth marked from BGL(RL 121.07m).(Shirlaw & et. al. 2003)
Collected Fort Canning Boulders and In-situ outcrop (Shirlaw& et. al. 2003)
3.2.3) Fort Canning Boulder Bed
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A cross section of Fort Canning Boulder bed and associated rocksfrom Raffles City toRaffles Quay showing upper and lower boundaries of FCBB (Shirlaw & et. al. 2003)
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3.3) Stratigraphy of the Cenozoic Geology in Singapore (65 m.y – Present) (k.W. Lee, 2010).
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3.3.1) The Old Alluvium
OA Clay wedged by Esturarine Deposits, Bartley Road Deep Excavation
Upper OA wedged by puplish Shale, Punggol area (Courtesy of U Sai Maw Kham)
. Cross Bedded Sand with Scour and filled structure, Bartley Rd.
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Gullies as ridges and furrows in upper OA Clays A and Cross bedded fine Sand B stacked by another Channel with Coarse Sand C at Bartley Rd.
A B
C
Thinly laminate Sand layers A and a boulder sit on the bed B at just east of Changi airport run way.
A
B
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Collected OA Samples : Silt. Clayey SAND, Silty SAND
Silty SandClayeySandSilt
Gravelly Sand
Batley Deport
Marina South
Depositional Variations From Bartley Rd. To Marina South
Description
55
40
30
m
OA Clay
Scale
U MC
SILT
SILT
Silty to gravelly SAND
Silty to Clayey, SAND
Silty to Clayey, SAND
F 2
F 1
L MC
F 1
F 2
Fill
PC
PC
Silty to Clayey SAND
OA Clay
KallangFm.
70OA Clay
Silty to Clayey, SAND
Old Alluvium
PC
20
65
60
50
45
35
25
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Mud Silt F M C
OA Clay
Silty to Clayey, SAND
Correlation of Soil Profile from Bartley Road to Marina South
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Key points of the OA development
The OA was probably dominant by fluvial condition with subordinate marine sediments during Pliocene to Mid-Pleistocene (correlated with Lower Pleistocene Low eustatic sea level).The Kallang river was main channel characterized by low–sinuous braided channels at earlier and hi-sinuous at later stage caused aggradation, multi-stacked channel deposits.Deposited in faulted trough with repeated vertical movement andsmall block faulting.A bay line (Place where ceased fluvial dominance ) is probably passed at the junction of Upper Payaleber road way and Mac Pherson road. Shore Line : Contact between Coastal Plain and SeaShelf : Part of the Continental margin between the Shoreline andContinental slope
Depositional Variations of the Old Alluvium & Kallang Fm.
Naing Maw Than (2010)
Marina South, RL 101m
Bartley RdRL 120m
OA>45m
KL Fm.
12 KmNE
OA Clay
Estuarine
Shelf Area
Bay Line Mcpherson & Up Payaleber Rd
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tidal sediments
high gradient,low sinuosity
channeldeposits
high sinuosityfloodplainOne example is the progression that results from a relative sea level rise
High gradient, low sinuosity streams occupy incised valleys at a lowstand
Stream gradient decreases and sinuosity increases during transgression, forming amalgamated channel deposits
The highstand succession consists of channel deposits from low gradient, high sinuosity streams isolated within floodplain sediments
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Granites found under the Old Alluvium (After Ong, Moe Sein & et al., 2003).
Granite Core runs at the Loyang Ave. (After Ong, Moe Sein & et al., 2003).
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3.3.2) The Huat Choe Formation
During the period of early Pleistocene faulting, the kaolin–rich clay in fault controlled depression formed as small isolated ponds and lacustrine deposits unconformably on the Jurong Fm.,
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Distribution of Quaternary sediments in Singapore with bathymetric levels (Bird & et. al. 2003)
3.3.3) The Kallang Formation
Marine Clay Peaty Clay F2 : Silty CLAy F1: SAND
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Stratigraphic relationship of Quarternary sediments in Singapore (Bird & et. al. 2003)
Deposition of the Kallang Formation Members (Lee. 2010)
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Development of The Kallang Formation
(Upper Quaternary)
It consists of both marine and terrestrial deposits that is found in onshore incised river valleys, offshore and coastal areas.
The Kallang Formation
Marine Member (Km)
Alluvial Member (Ka)
Littoral Member (Kl)
Transitional Member (Kt)
Reef Member (Kr)
These deposits covers much of the coastal plane The most important unit is Marine Member that covers one quarter of Singapore with variable thickness with a maximum record of 35m.
It comprises upper and lower part. The Marine Clay is pale grey to dark blue in colour, soft, silty, kaolinite-rich and shell fragments.
The low sea levels associated with the penultimate glacial (Riss) stage. Rivers downcut their valleys to at least –55m. As sea level rose following glacial Riss stage about 14,000 BP, the lower member was deposited (Bird et al. 2003).
The transitional member (Kt) and the Littoral memebr (kl) were deposited near the shore line and the Alluvial member was deposited in river valleys on shore.
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When the sea level stood at – 120m during the last Glacial Max at about 20,000 BP stiff, reddish brown clay F2 was developed at the top of the lower member. vegetation grown on F2 layer and became Peat layer E that was in turn capped with sandy, shallow water deposits F1 Sand.
At the end of the last Glacial Max (during the closing phase of the last glacial Wurn stage), sea level rose rapidly and Singapore was flooded when it was about –25m at about 10,000 BP.
The Transitional (Kt) and Littoral (Kl) members were deposited repeatedly near advancing shoreline with similar facies of Tekong formation.
Further offshore, the Upper Marine Member was deposited over the Transitional and Littoral Member, and onshore,theAlluvial Member was deposited.
The sea level stand at about 2 to 2.5m above present sea level at 6,000 BP allowed the deposition of TekongFormation.
Since 6000, sea level declined steadily to the present and Upper Marine Member was overlain by the Alluvial Member and transitional Member.
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The Paleozoic sedimentary structures indicate a longer and more complex tectonic history. The intrusion and uplift of the granite presumably started in the Upper Paleozoic and become strongly evident in the Triassic time.
The Triassic sediments were laid down in a mobile N_W trending trough bounded on either side by rising granitic hills (coarse clasts in sedimentary rocks suggests the bulk of the granite was buried at the same time).
The rate of uplift of the main range granite in the SW of troughappears to have been more rapid. This lopsided uplift caused the trough and tilt NE and gave way sediments against the upliftof Bukit Timah granite.
The dynamic metamorphism that gave rise to Murai schist accompanied with this sliding and assumed that Malay penisularwas raised above sea level from that time.
Alternatively, the Triassic sediments of Jurong Formation could have been uplifted, tilted, dislocated, piled on top of one another in late Cretaceous when the Wyola continental fragment collided with the east Malaysia block that may caused the Fort Canning Boulder Bed.
IV) Tectonic History and Structures
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That was also widespread shallow thrust faulting, shallow foldedand metamorphism such as slates, phyllites, and schistose sandstone at many locations away from Murai Schist.
Tectonic activity recommended the late Tertiary with block faulting and warping.
The Old Alluvium and Huat Choe Formation were deposited in the depression that had formed. After the cessation of warping, river valleys were cut in the Old Alluvium and older rocks.
The valleys and coastal areas are subsequently backfilled with sediments of the Kallang Formation during late Pleistocene and Holocene.
During mid-Holocene, coastal area were covered with TekongFormation and The Kallang Formation continue to be deposited except the Lower Marine member in present day.
IV) Tectonic History and Structures
SE Asia Basins & Tectonic Framework
Nee Soon
Seletar
PasirPajang
Nanyang
Tg. Gadong
Tg. Lokos
Faults alignments in Singapore (From K.W. Lee, 2010)
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Wrench Faulting in Singapore during Late Cretaceous (From K.W. Lee, 2010)
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Parallel A and oblique B joint sets in eastern granite at Pulau U Bin (Courtesy of U Kyaw Htin Khine)
A
B
Quartz vein along with syn sedimentary fault (?) at Labrador park (Courtesy of Dr.Kyi Khin, U Khin Latt)
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The lines shown are real trend lines, mostly representing the regional strike of regional folds or strike of beds.
The regional pattern swings southeastwards through Singapore and then due east from Billiton. This bending can be achieved only by slippage on each vertical plane.
There are therefore many right-lateral wrench faults. Rotations and trans-extension and trans-pressionfollow.
Geological Evolution of SE ASIA, C.S. Hutchison (1996), Pg 61
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References:1. Bird M.J., J.N.Shirlaw & et.al. The Age and Origin of quaternary Sediments of Singapore with emphasis on the Marine Clay, Proceeding of Underground Singapore 2003, Engineering Geology Workshop2. Chiam.S.L., K.S. Wong & et.at., The Old Alluvium , Proceeding of Underground Singapore 2003, Engineering Geology Workshop3. DSTA, Geology of Singapore (2nd Ed, 2009)4. Lee K.W. & et.at Limestones of the Jurong Formation, Proceeding of Underground Singapore 2003, Engineering Geology Workshop,5. J.J. Lambiase. Lecture Notes on Reservoir Sedimentology (UniversitiBrunei, 2005)6. K.S.Wong & et al. Old Alluvium Engineering Properties and Braced Excavation Performance, Proceedings of Underground Singapore 20017. Lee kim Woon, SRMEG_GEOSS Workshop on Geology of Singapore5th April 20108. Moe Sein, J.C.W. Ong & et al. Buried Granite Ridges in Old Alluvium Proceeding of Underground Singapore 2003, Engineering Geology Workshop9. Naing Maw Than,The Occurrences of Old Alluvium, Singapore
(presented at MGSS 1st technical Seminar, June 2010) 10.Shirlaw J.N. & et.at., Fort Canning Boulder Bed, Proceeding of Underground Singapore 2003, Engineering Geology Workshop
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Thank You !
• Sincere thanks to MGS personnel to arrange this presentation and other social networks for Myanmar Geology Society.
• This presentation is a comprehensive note dedicated to persons who resume to understand on neighborhood geology of SE Asia and resume to work with Singapore.
• It is based on previous works and just a jig-saw work of scattered data of (Bartley Rd. Viaduct, KPE, Marina South) and knowledge shared by colleagues that still need additional findings.
Best Regards,
Naing Maw Than