Postgraduate Project and/or Vacancy for Research Assistant Position: Seismic – Sequence Stratigraphic development of the West Luconia Province, offshore Sarawak, Malaysia

The Source to Sink Group at the Geology Department, University of Malaya is conducting a regional tectono-stratigraphic study of offshore Sarawak.

We are seeking one candidate: either MSc or  1 PhD candidates (preferable).

The objective of the study includes constructing a sequence stratigraphic and tectonostratigraphic framework for the West LLuconia Province, to construct geological and geophysical models for subsidence and forward kinematic modelling and understanding the relationship between tectonic uplift, exhumation and basin formation.

The offer includes a position as a Research Assistant with monthly pay.

The project is a collaboration between the University of Malaya and Utrecht University, and will include several months working at Utrecht

Basic requirements:

Malaysian

Experience with seismic and well log interpretation

Experience or interest in sequence stratigraphy/sedimentology. Knowledge of Sarawak Geology an advantage

Working knowledge of seismic and well log analysis (e.g. Petrel, Kingdom, Seisworks etc.)

Must be independent, hardworking, capable of producing results without much supervision

MSc in relevant field (Geology, Petroleum Geology, Geophysics) or good BSc (preferably CGPA 3.0 and above)

Has plans on pursuing a MSc or PhD in Seismic Sequence Stratigraphy, basin history and/or analysis

For further information, please email: meorhakif@um.edu.my

If interested, please send your CV with a cover letter.

Dinosaur footprints at Phu Faek Forest Park, Thailand

A few weeks back, I attended a field excursion to northeastern Thailand organised by the Department of Mineral Resources, Thailand with the Department of Minerals and Geoscience Malaysia. One of the interesting sites we visited was the dinosaur footprint locality at Phu Faek Forest Park.

 

The footprints were preserved on the top surface of a sandstone bed. The three toed tracks have been identified as the footprints of a theropod dinosaur.

Sedimentary features of associated deposits include ripples, lamination and climbing ripples. Dr Asanee Meesok mentioned that the footprint bearing bed was part of ancient braided river bed. The rocks are Early Cretaceous in age.

i took a lot of photos of one of the better preserved footprints:

 

 

Then, I just put the photos through the free Autodesk123DCatch app to make a 3D photogrammetry model. Luckily it turned out well:

I wished I had spent more time there, so that I could have tried to photograph  a set of track, but there were many more amazing sites to visit during the trip. Maybe next time

Symmetrical ripples in wave-dominated environments (Part II)

I went on and on about symmetrical wave ripples in my previous post that I forgot to put any photos of examples. Se there are some.

The top of this tilted sandstone bed from Labuan Island preserves numerous symmetrical ripples, formed by waves approximately 20 million years ago.

A close up of the bed shows the symmetrical profile of the individual ripples. Internal cross laminations are also observed.

Coincidentally, the rock exposure is along the coast, where you can also see modern day symmetrical ripples recently formed by waves. Bedforms produced by the same physical forces, separated by 20 million years.

 

 

 

Symmetrical ripples in wave-dominated environments

After doing tidal deposits previously, I thought I might continue with wave deposits.

Transport and deposition in wave-dominated environments is characterised by
oscillating currents, wave shoaling and storm events. At normal fairweather conditions in the shallow subtidal region, this results in the modification of sand beds into symmetrical ripples.

Cartoon profile of symmetrical ripples. the angle of steepness on both sides of the ripples are almost equal to each other (modified from de Raaf et al., 1977).

Two types of waves affect shorelines: (1) swell waves, which are fast travelling,
long period waves generated thousands of km out in the ocean and; (2) short period sea
waves generated by nearby storms and prevailing winds. Waves produce oscillating
currents on the sea surface due to friction. The oscillatory motion of the sea surface produced by waves results in a circular pathway for water molecules in the top layer. A series of circular cells are produced in the water below. In shallow water, the base of the water body interacts with the waves. Friction causes the circular motion at the surface to become transformed into an eliptical pathway, which is flattened at the base into a horizontal oscillation. This is expressed as rapidly alternating opposing flows.

Interaction of the oscillatory flow with sand at the shallow see bottom produces symmetrical vortex ripples, which form as sand is transported by vortices or eddies over growing ripple crests (Inman and Bowen, 1963).

Formation of vortex ripples. Modified from Inman and Bowen (1963).

The video below clearly shows the rapidly alternating and opposing flows due to oscillatory wave motion, resulting in symmetrical ripples

Reference:

De Raaf, J.F.M., Boersma, J.R., Van Gelder, A., 1977. Wave-generated structures and
sequences from a shallow marine succession, Lower Carboniferous, County Cork, Ireland.
Sedimentology 24, 451-483.

Inman, D.L., Bowen, A.J., 1963. Flume experiments on sand transport by waves and
currents. Proceedings of the 8th Conference on Coastal Engineering, Berkeley, California,
pp. 137-150.

Perlis: A Geological Paradise

I never get tired of visiting Perlis. Personally it is one of the most beautiful places on the Malay Peninsula. Despite being the smallest state in the Federation (total area 821 square km), the topography changes dramatically, from high mountain range in the west, steep karst hills in the centre and wide plains with paddy fields in between. The inhabitants are mostly typical northerners, friendly, practical and fiercely independent.

In terms of geology, Perlis is unique. It preserves one of the most complete Palaeozoic sedimentary records in the region, with an almost continuous succession from Ordovician, Silurian, Devonian, Carboniferous to the Permian. As highlighted in previous posts, these rocks are highly fossiliferous, and is one of the best fossil hunting localities in Malaysia. I always try to make time to collect fossils from Perlis, and new fossil species are progressively being described from the state.

The photo above was taken from a recent trip there (just last week). It was taken atop the Guar Sanai ridge and is facing towards the north. On the left side of the photo (west), you can see part of the imposing Setul or Nakawan Range, which trends north – south, reaches 553 m high and forms a natural border between West Thailand and Northwest Peninsular Malaysia. The Setul Boundary is composed of hard limestone of Ordovician age (the Kaki Bukit Limestone of the Setul Group, also traditionally known as the Setul Limestone). The small ridges east of the range (including the one where I took the photo) preserve a mixed clastic and carbonate succession of Silurian to Carboniferous aged rocks, with a rich fossil assemblage. The Chuping Limestone (the small hills jutting out from the flat plains in the right side of the photo) forms a series of North – South trending hills in central Perlis.

Benthic fossils in black tentaculitid shales, Perlis

The strata of the Early Devonian Timah Tasoh Formation in Perlis is made up of a mixture of organic-rich terrigenous clay and silt mixed with the abundant remains of ancient planktonic organisms called tentaculitids. At some intervals, the tentaculitids are almost rock forming, with very little other material. Fossils of benthic animals are relatively rare. This, combined with the abundance of planktonic and pelagic fossils has led to the interpretation of the unit as representing a relatively deep water environment away from shore (if we were nearer to the shore and in shallower waters, you would expect to have coarser grained sediment such as sand, due to stronger waves in the shallows, and you would also expect a lot more benthic organisms). Water depth has been estimated to be around 150-200m.

However, occasionally, you would find some benthic fossils in the Timah Tasoh Formation, mainly in the form of small brachiopod and trilobite remains. The photo above shows the tail end (pygidium) of the trilobite Plagiolaria (lower right corner of photo).

The trilobite Plagiolaria also tells us something of the environment. The second photo above is part of the head of Plagiolaria (the left side of the head is broken off. Notice the small oval structure on the right side of the head. That is the right eye of this animal. Plagiolaria has relatively small eyes compared to other more common types of trilobites. The development of small eyes (and sometimes the absence of eyes) in some trilobites has been found to be associated with water depth, where blind and small-eyed trilobites being more common in deeper waters.

 

References:

Crônier, C., Fortey, R.A., 2006. Morphology and ontogeny of an Early Devonian Phacopid
1121 trilobite with reduced sight from southern Thailand. Journal of Paleontology 80(3), 529-536.

 

Meor, H.A.H., Erdtmann, B.D., Wang, X.F., Lee, C.P., 2013a. Early Devonian graptolites
1336 and tentaculitids in northwest Peninsular Malaysia and a revision of the Devonian –
1337 Carboniferous stratigraphy of the region. Alcheringa 37(1), 49-63.

 

 

 

Trilobite cheek: Waribole perlisensis

Just a show post, basically to show this photo.

 

Its the left cheek (librigena) of the small trilobite Waribole, Early Carboniferous, Kubang Pasu Formation of Perlis. Sorry about the upside down orientation and poor quality (rough job using a macrolens), but just wanted to showcase the well preserved eye. I’m planning to get a better microscope for photographing specimens, so hopefully I’ll get a better close up of just the eye next  time.

Posidonia from the Kubang Pasu Formation, Perlis

Again, I have been neglecting the blog for some time, but I’ve been digging out some specimens from my dusty drawers for a conference presentation I’m preparing.

Here are some nice specimens of the Carboniferous bivalve Posidonia, again from my favourite stratigraphic unit, the Kubang Pasu Formation.

 

These fossils are pretty big (6-7cm long), compared to the more common, minute brachiopods and trilobites associated with it. In this case, the original carbonate content of the shells have been replaced by the mineral pyrite. The pyritised shells are usually found in dark coloured mudstone, alongside with fossil ammonoids.

However, not all shells are pyritised, such as this one:

These are usually associated with red or grey coloured mudstone beds in the Kubang Pasu Formation.

The bivalve Posidonia (in this case, possibly the species Posidonia becheri) is a pseudoplanktonic bivalve, commonly associated with deeper shelf deposits of the Carboniferous age ‘Culm Facies’ in Europe, and its distribution also extends into Turkey, South China and Malaysia. All these areas were parts of continental terrane that drifted from the supercontinent Gondwana during the Palaeozoic, and the Posidonia-bearing mudstones represent the marine shelf area skirting the ancient Palae-Tethys Ocean.

 

References

Hosgor et al., 2012. Posidonia becheri Bronn, 1828 from the Tournaisian of SE Turkey: A palaeobiogeographic enigma. Comptes Rendus Palevol 11(1), 13-20 

Sarkar, S.S., 1972. On the Posidonia from Rebak Islands Langkawi, West Malaysia. Geological Society of Malaysia Newsletter 37, 5-10.

 

MSc or PhD Opportunity in Source to Sink Study (For Malaysian)

Our group at the Geology Department, University of Malaya is conducting a regional tectono-stratigraphic study of onshore Peninsular Malaysia, onshore Sarawak and adjacent offshore basins (Malay and Sarawak basins).

We are seeking two candidates: either 2 MSc or; 1 MSc and 1 PhD candidates. The objective of the study includes constructing geological and geophysical models for subsidence and forward kinematic modelling and understanding the relationship between tectonic uplift, exhumation and basin formation.

The offer includes a position as a Research Assistant with monthly pay.

The project is a collaboration between the University of Malaya and Utrecht University, and will include several months working at Utrecht

Basic requirements:

Malaysian

Bachelor of Science Degree in Geology/MSc in Geology

CGPA 3.0 and above

Good command of English

Hardworking, able to maintain motivation for a long term project

Ability to adapt to setbacks and obstacles

Able to work in a team

Experience/knowledge of Geology and Geophysics software (Petrel, Roxar RMS, Kingdom, Seiswork etc.) and well log and seismic interpretation is an advantage

For further information, please email: meorhakif@um.edu.my

If interested, please send your CV with a cover letter.

Sarawak Ammonites

Again, sorry for the long hiatus.

I was talking with one of my old professors a few weeks back about my most recent trip to Kuching. He then handed me these:

These are fossil ammonites collected by one of the department’s students a while back. Unfortunately, as the first picture shows, we don’t know precisely where these are from (the piece of paper just says from some school). This is driving me crazy, but I dont think I can spare time to go and survey every school in the district. So if anybody knows anything about these specimens, please share.

Ammonites have been reported before from Sarawak (see Ishibashi, 1982) from the Jurassic and Cretaceous marine beds, so these are not particularly unusual. However, the fossil have got me thinking about something else: Dinosaurs!

The Kayan Sandstone is composed of cross-bedded sandstone and tidal heteroliths, probably representing a coastal-coastal plain environment. The age of these deposits are supposed to be Late Cretaceous to Eocene. So maybe, just maybe, there are fossil horizons rich in dinosaur remains just waiting to be discovered near Kuching (and if your interested in a research project, send me a message).

Reference:

Ishibashi, T. 1982. Upper Jurassic and Lower Cretaceous Ammonites from Sarawak Borneo, East Malaysia. In: Kobayashi, T., Toriyama, R., Hashimoto, W. (Eds), Geology and Palaeontology of Southeast Asia, vol. 23: 65-75.