Geology of North-West Borneo

Sarawak, Brunei and Sabah

C.S. Hutchison

• Publisher: Elsevier Science
• Year: 2005
• Print ISBN: 9780444519986
• eBook ISBN: 9780080460895
• Topic: Physical Sciences
• Subtopic: Geology & Earth Sciences

The book is a comprehensive compilation of all aspects of the geology of Northwest Borneo (Sarawak, Brunei and Sabah) and the contiguous South China and Sulu Seas. The sedimentary formations are described, their palaeontology tabulated and ages discussed. Stratigraphic charts illustrate their relationships across the whole region. Detailed geological maps of selected areas are accompanied by cross sections based on outcrop patterns and drilling and seismic data offshore. Palaeocurrent maps are presented and the palaeogeography for different ages described and sedimentary provenance discussed. Descriptions of the ophiolite sequences, volcanic and plutonic rocks are accompanied by tables of selected chemical analyses and geochemical plots and their tectonic significance discussed. All radiometric data are tabulated and discussed. Regional structures and the predominantly Tertiary tectonics are described. In Sarawak the mountains are constructed of Upper Cretaceous to Lower Eocene greenschist facies shaly turbiditic Rajang Group, uplifted before the end of the Eocene. In Sabah the Western Cordillera is constructed of Eocene to Lower Miocene sandy turbidite uplifted in the Late Miocene and Pliocene. Miocene intrusion of Mount Kinabalu and uplift of the Cordillera is related to collision at the Northwest Borneo Trough. Gold, antimony, mercury and copper deposits are described and the tectonic setting of oil and gas deposits discussed.* Correlation tables, descriptions and ages of all major sedimentary formations of Sarawak, Brunei and Sabah* Petrology, geochemistry and ages of all volcanic and plutonic formations of North West Borneo and their tectonic significance* Economic geology including the geological setting of offshore oil and gas deposits

Part B

Sabah

Outline

Chapter X: Introduction

Chapter XI: Geomorphology

Chapter XII: Introduction to the Stratigraphy

Chapter XIII: Sulu Sea Marginal Basin

Chapter XIV: The Ophiolitic Basement

Chapter XV: Eastern Rajang Group (Gallic to Eocene)

Chapter XVI: Rajang Group (Western)

Chapter XVII: Kinabatangan Group

Chapter XVIII: Crocker Formation (including the Temburong Fm.)

Chapter XIX: Uplift of the Crocker and Trusmadi Formations

Chapter XX: East Sabah Mélanges

Chapter XXI: Tanjong Group ‘Circular Basins’

Chapter XXII: Dent Peninsula Volcanics and Pyroclastics

Chapter XXIII: Dent Group

Chapter XXIV: Semporna Peninsula Volcanism

Chapter XXV: Mount Kinabalu Granitoids

Chapter XXVI: The East Baram Delta

Chapter XXVII: Brunei Darussalam: Geological Link Between Sabah and Sarawak

Chapter XXVIII: Offshore Brunei and Sabah

Chapter XXIX: Mineral Deposits

Chapter XXX: Coal Deposits

Chapter XXXI: Petroleum

Chapter X

Introduction

Publisher Summary

This chapter provides an overview of the geology of Sabah. It also discusses the Chert–Spilite formation, ultrabasic and basic rock, crystalline schists, crystalline basements, calc–alkaline granitoids, and modern interpretation of ophiolite. Chert–Spilite is also known as the Danau Formation for a characteristic association of diabase and chert. Large regions of Sabah are characterized by ultrabasic and basic plutonic rocks, recognized as ophiolitic. The basic plutonic rocks are commonly layered and the ultrabasic rocks demonstrate a similar fabric. Crystalline Schists are the metamorphosed ophiolitic rocks and it is difficult to distinguish between the occurrences of crystalline schists and those of the ophiolite of the Danau Formation. The same banded dioritic and acid igneous rocks are sub divided into a crystalline basement and a separate group of banded gabbros and associated ultramafic rocks. Several bodies of calc–alkaline granitoids occur within the crystalline basement of the Segama area. The ophiolites represent uplifted ancient oceanic lithosphere of smaller marginal basins. Tectonic imbrication and deep weathering are major obstacles. However, the stratigraphic problems of Sabah remain and may never be completely resolved.

The first landmark in the beginning of understanding of the geology of Sabah was the publication of Reinhard and Wenk (1951). In 1948, the Shell Oil Company informed the Colonial Office that it had arranged for Professor Max Reinhard and Dr Eduard Wenk of Basel University to compile a comprehensive report on the geology of North Borneo. Both had previous field experience in the country. It was published as the first bulletin of the newly created Geological Survey Department. All the fieldwork on which it was based was completed before 1942. The manuscript was mostly written in German and translated by staff of Royal Dutch Shell in The Hague.

X.1 CHERT–SPILITE FORMATION

Molengraaf (1902), from his mapping of the lake region of Kalimantan, had coined the term Danau Formation for a characteristic association predominantly of diabase and chert. Reinhard and Wenk (1951) followed the terminology, now firmly interpreted as an ophiolite association. Fitch (1955) used the term Chert–Spilite Formation for what formerly was known as the Danau Formation. Wilson (1961) and Kirk (1962) ensured that the term Chert–Spilite Formation became widely accepted in the stratigraphic nomenclature of Sabah for a characteristic association of spilite, pillow basalt and ribbon chert. However the ophiolitic nature, clearly recognized in the term Danau Formation, became lost within the usage Chert–Spilite Formation. A major problem also arose because other apparently unrelated rocks were included and the Chert–Spilite Formation became something of a miscellanea.

X.2 ULTRABASIC AND BASIC ROCKS

Large regions of Sabah are characterized by ultrabasic and basic plutonic rocks, clearly recognized as ophiolitic (Kirk, 1968), but their link with the Chert–Spilite Formation, following the wisdom of his ophiolitic ‘Trinity’ (Steinmann, 1906), was not made in Sabah until later. The basic plutonic rocks are...

Table of contents

• Cover image
• Title page
• Table of Contents
• Acknowledgements
• Introduction
• Regional Tectonic Setting
• Part A: Sarawak
• Part B: Sabah
• References
• Index