November 12, 2008

Langkawi: The Malaysia Geopark


The first Geopark, not only in Malaysia, but Southeast Asia. The Machincang Formation in the North West of the Island is the oldest in the world at 550million years old. Langkawi has not been called the bithplace of the region for nothing! The Chuping Limestone at Pulau Dayang Bunting, dating back some 280million years, and the north eastern part of Langkawi easily have some of the most beautiful and intriguing formations you've ever seen.

But the Geopark concept is made up of more than mere geological structures and landscape. It is about how the local communities within it sustain and nurture this geological heritage through effective conservation efforts and promotion of ecotourism.

Essentially it is about whether the people living within the Geopark realise that these invaluable geological gems belong to them and their future generations.

Oldest Rock Formation
The natural construction of these features greatly influenced the types of rock formation. Datai Bay is a sequence of interbedded sandstone and shale which is called Machinchang Formation aged 550million years old and regarded as the oldest rock in Malaysia. Indeed this area is one of the most important geological sutes in Malaysia which must be preserved and protected for educational and reserceh purposes.

High Geological Value
Datai Bay also has a great diversity of rocks, structural and landform, which contributes to the high geological value of the site. The rock diversity is easily defined by the rocks types within the Machinchang Formation. At the Bay, this sedimentary rock as identified along the rocky beach is a layer of dark shale and fine to coarse grain sandstone. Most of the rocky beach to Tanjung Hulor. To the east, towards Anak Datai Island, the coarse grain sandstone becomes dominant. The diversity of rocks in Datai Bay is a record of environmental change during the period of sediment deposition 550million years ago. The deposition environment during that time is believed to be river deltas and shallow coastal areas.

Primary and Secondary Structures
Structural diversity in the Machinchang Formation can be viewed at the rock exposure along the rocky beach. Rock structures formed during the sediment deposition are called the primary structure, and by tectonic activity are known as the primary structure. Primary structures such as planar bedding and cross lamination are found along the rocky beach, while the secondary structure consists of faults, folds, joints and quartz veins intrusions.

Coastal Outlines and Soft Sand
The landform diversity at Datai Bay is a plethora of wonderful coastal types; rocky beach, sandy beach, pebbly beach, abrasion platform, depositional platform, gravel bar, sea tracks, sea caves and residual island. The sand here feels extremely soft beneath bare feet. The series of abrasion platforms along the rocky beach display the structure painted on them. Great persistence by the wave and erosion processes had shaped the pebbles on the beach into semi rounded, rounded and pellet like. The works of the tireless wave with the help of structures within the rock had eroded part of the promontory to form residual islands and at the small scale they are called sea tracks. At an area where the wave is strong, such as at the west of Anak Burau Island, the erosion along the vertical layer of rocks had formed sea caves and rocky arches.

Tourism Education
Datai Bay is one of the sites in South East Asia with significant geological history. It also perfectly showcases the coastal landscape for sedimentary rocks. The diverse landscape in this area provides a great opportunity for research and tourism education. Not to mention a living exhibition of beguiling rock formations.

From www.langkawi-online.com

Ketakselarasan Strata Triassik-Kuateneri, K. Krai



Satu singkapan batuan yang mempamerkan ketakselarasan antara strata Triassik dan Kuateneri telah dicerap pada satu cerun potongan bukit di hadapan Dataran Peladang, Kuala Krai, Kelantan. Litologi strata Triassik terdiri daripada saling selang lapis batu lumpur putih dengan batu lumpur kelabu dengan jurus 040 miringan ke barat laut. Manakala strata Kuarteneri pula mewakili lapisan batu lumpur dengan beberapa lapisan berpebel yang mendatar. Klasta berpebel terdiri daripada kuartzit dan klasta bersaiz buntar juga boleh dicerap dalam lapisan tersebut. Lapisan berpebel dapat dicerap pada bahagian sentuhan ketakselarasan dan pada bahagian atas singkapan.

November 11, 2008

Konglomerat Lanis, Kumpulan Tembeling







Singkapan Konglomerat Lanis dapat diperhatikan di Kg. Penjing, Maran, Pahang pada beberapa cerun potongan bukit utk pembinaan jalanraya yang menghubungkan Bera ke Paloh Inai. Jalanraya tersebut didapati memotong strata batuan Kumpulan Tembeling. Singkapan sedemikian juga dapat diperhatikan di Lebuhraya LPT berhampiran Bandar Maran dan jalanraya Jerantut-Maran berhampiran Sg. Jerik dan Pulau Tawar.

Konglomerat Lanis adalah sebahagian dari ahli Kumpulan Tembeling yang mungkin dilapisi secara selaras oleh Batu pasir Mangking dan melapisi formasi Kerum secara selaras. Litologi singkapan ini terdiri daripada turutan konglomerat polimitik dengan klas yang terdiri daripada sandstone, syal dan batu lodak serta volkanik. Manakala matriknya terdiri daripada lodak dan pasir merah. Lapisan syal berkarbon turut ditemui sebagai kekanta atau sebagai lapisan masif. Tidak ditemui sebarang bentuk fosil. Namun begitu usia pengenapan unit batuan ini adalah dianggarkan Jurasik Atas ke Kapur Bawah.

November 5, 2008

Geological Museum, Ipoh


INTRODUCTION

The foundation stone of the Mineral & Geoscience Department (formerly Geological Survey Department) building in Ipoh was first laid by YM Raja Idris Shah ibni Almarhum Sultan Iskandar Shah, the Raja Muda of Perak in July, 1955. The building which also housed the Geological Museum was then officiated by Sir Donald MacGillvray, the then High Commissioner of Malaya in 1957.

The museum gallery was expanded in 1978 to its present occupying space on the first floor of the building. Following the merger between the Geological Survey Department and Mines Department in 1999, the museum was renamed the Geological and Mining Museum. Steps are presently being undertaken by the Department to expand the present gallery space and to add in more exhibits.

The museum exhibits a wide array of specimens related to the field of geoscience and mining activities in Malaysia besides introducing to the public on the various activities carried out by the Department.

LOCATION

The museum is located within the JMG Malaysia building complex which is about 5 km to the east of the Ipoh City along Jalan Sultan Azlan Shah, and faces opposite Sekolah Tuanku Abdul Rahman (STAR).

GALLERY EXHIBITS AND COLLECTIONS

The gallery presently occupies a space of around 343.3 square metre. The exhibits are arranged as such whereby the mineral specimens are displayed according to the classification of chemistry and its structure, rocks in accordance to its origins, and fossils according to its age.

Geological, geochemical, hydrogeological, geophysical and mineral resource in the form of thematic maps are among the exhibits available. An interesting geological time-scale illustrates the evolutionary trend of life from the beginning of the earth's formation. Also on display are some 600 mineral specimens. 150 rock specimens, 200 fossil exhibits and 200 gemstones and ornaments, mostly of Malaysian origin.
Models and colour photographs of geological structures and minerals and fossil specimens have been added in stages to improve the scope of the museum display.
The photographic laboratory in the department has colour slides of geological specimens. A TV/video show is available to present the main activities of the department.

OPENING HOURS


Morning

Afternoon

Monday – Thursday

8.30 – 1.00

2.00 – 4.30

Friday

8.30 – 11.45

2.15 – 4.30

Note: The Museum is closed on Saturdays, Sundays and Public Holidays.

Group-visits to the Museum are most welcome. Briefing during the visit can be arranged if notified officially in advance to the:-

Director of Technical Services
Technical Services Division
(Geological and Mining Museum)
MINERALS AND GEOSCIENCE DEPARTMENT MALAYSIA
Jalan Sultan Azlan Shah,
P.O. Box 1015
30820 Ipoh

Tel: 05- 5406000
Fax: 05-5406100
Email: muzium@jmgipoh.gov.my

ADMISSION

F R E E

November 2, 2008

Outline Geology of Peninsular Malaysia

Malaysia is a country which consists of two parts, peninsular Malaysia and East Malaysia (Sabah & Sarawak or Borneo). The capital of Malaysia is Kuala Lumpur and divided into 12 states, each having own capital town. The climate is tropical characterised by uniformly high tempaerature and seasonal rainfall. Most of the region is covered by a tropical rain forest.
Up to 1903, all geological work had been reconnaissance. In 1903, J.B. Scrivenor was appointed as the first government geologist and this begun the new era of geological work in Peninsular Malaysia. Systematic mapping by the Geological Survey was started in the 1930's. Since the 1970's there has been a rapid increase in the geological knowledge of Peninsular Malaysia. The latest geological map (1:50,000) of Peninsular Malaysia was published in 1985 by the Geological Survey of Malaysia (now known as Minerals and Geoscience Department Malaysia).
On the basis of tectonostratigraphic terrains, Malaysia is a part of Sibumasu block and East Malaya block. Peninsular Malaysia can be divided into three belts; West Malaya, Central Malaya and East Malaya. Each of these three belts is characterised by its own stratigraphy, igneous suite and geological history.

In West Malaysia, the oldest rocks exposed are Cambrian in age, consisting of about 3000m of predominantly sandstone-shale deposited in a shallow water and deltaic environment. This rocks well expose in northwest Peninsular Malaysia and are conformably overlain by the thick sequence of shallow water limestone of Ordovician to Silurian age. Both sequences then overlies by the rock of Upper Devonian to Lower Carboniferous which is dominated by mudstone, sandstone and thin of pebbly mudstone. Limestone and siliciclastic of Triassic age are best developed in northwest Peninsular Malaysia and were intruded by granite of latest Triassic to Jurassic age.

In Centrel Malaya, the oldest rocks exposed are Silurian-Devonian rocks called as Bentong Group. These rocks exposed in a narrow zone and consists of schists, amphibolites, conglomerates and other siliciclastic deposits with some bodies of serpentinite and melange deposits. During Triassic period, deposits are dominated by marine sediments and overlain in some areas by Jurassic-Cretaceous continental deposits. Marine Permian and Triassic rocks were deposited over the Bentong Group and cover the greater part of the Central Malaya.

East Malaya is dominated by Carboniferous and Permian clastics, carbonates and volvanics. Triassic sediments absent and Upper Jurassic continental rocks lie unconformably on the Carboniferous-Permian sequence.

The main intrusive body in west Malaya is the Main Range Granite (S-type) extending 3000km from the southern tip of Peninsular Malaysia to Northern Thailand. In Central Malaya granitic intrusives extend from the Thai border southwards to Johore. In East Malaya, granites are abundant froming elongated north-south trending bodies. These granites are classified as I-type. Source- Dr. Kamal Roslan, UKM

Wedge Failure, Pos Belau


Satu cerun potongan bukit berhampiran Pos Belau, Gua Musang, telah mempamerkan kegagalan cerun jenis baji. Terdapat dua ketakselarasan major telah dicerap pada muka cerun tersebut yang dikawal oleh satah perlapisan dan kekar. Pengukuran arah dan junaman ketakselanjaran ini memberikan garis persilangan dan menghasilkan 'daylight' pada muka cerun. Bahan cerun mengelongsur turun pada sepanjang garis persilangan apabila sudut junaman garis persilangan lebih kecil dari sudut kemiringan muka cerun. Dari analisis stereonet, didapati bahawa arah dan sudut junaman adalah 25/162 dengan sudut junaman garis persilangan lebih kecil dari kemiringan muka cerun yang menyebabkan gelongsoran baji berlaku.

A cut slope adjacent to Pos Belau, Gua Musang displayed wedge failure. Two major uncontinuities have been observed on slope face. From the measurement of the orientation and the inclination of these discontinuities shows that the line of intersection will result daylight in the slope face. Rock mass slide along the line of intersection when the plunge of this line is less than the dip of the slope face. Stereonet analysis shows that the orientation and plunge of this failure is 25/162 where the line of intersection is less than the dip of the slope and consequently, wedge failure occur.