Although several geologic maps of Taiwan had been published in earlier years by the Japanese-geologists, the
most recent one was a 1:300,000 map printed in 1953 by the Chinese geologist, L.S. Chang, not long after the
end of World War II. Since the publication of the 1953 map, much more systematic geologic study has been
done in most areas of this island. Great advances have been made in geologic mapping throughout the province
of Taiwan and a large number of detailed regional maps have been compiled. As a result, many of the earlier
stratigraphic classifications and structural interpretations have been modified, and these modifications have
improved our knowledge of the geology of Taiwan substantially. Consequently the compilation of a new geologic
map of Taiwan incorporating the results of geologic mapping during the last 20 years is long overdue.
The preparation of the new geologic map of Taiwan is a project initiated by the Department of Mines of the
Ministry of Economic Affairs in 1973. Representatives from The Geological Survey of Taiwan, the Chinese
Petroleum Corporation, the Mining Research and Service Organization, and other research institutions and
universities met to discuss the proposed new map. It was decided that the new geologic map of Taiwan should
be compiled and published on a 1:250,000 topographic base. To facilitate this work, a geologic map committee
was established under the auspices of the Ministry of Economic Affairs. The committee was composed of six
members: Biq Chingchang and S.F. Tsan of the Geological Survey of Taiwan, C.Y. Meng and Stanley S.L. Chang
of the Chinese Petroleum Corporation, and C.T. Chung of the Mining Research and Service Organization, with
C.S. Ho designated as the chief compiler. At the several meetings of the committee, the means and technical
standards to be used for the compilation of the map were discussed and agreed upon. Final specifications for
the representation of geologic data on the map were adopted by the committee members. Work on the geologic
map was begun by the chief compiler in August 1973, and completed and published in October, 1974. Editing
was constantly guided by the members of the geologic map committee during periodic meetings. Printed copies
of the map were released in February, 1975, and an explanatory text was published in December, 1975.
The new map has been compiled from data and information available up to the early part of 1974, mainly from
the published geologic maps and other data of the Geological Survey of Taiwan together with data supplied by
other agencies and institutions. The Chinese Petroleum Corporation supplied geologic maps and other materials
of the potential oil-bearing areas in western Taiwan in addition to selected data produced during current
exploration. The Mining Research and Service Organization supplied data on the submetamorphic belt in the
northwestern part of the Central Range. The 1:250,000 base map was supplied by the Chinese Petroleum
Corporation, and was prepared by the Chinese Society of Survey Engineering based on the data of China Map
Service CCSF. Drafting was done mostly at the Taichung office of the Geological Survey of Taiwan under the
direction of C.H. Wu who, along with C.S. Ho, also supervised the color printing. The map was printed by the
Chinese Society of Survey Engineering, whose full cooperation on this project is gratefully acknowledged.
Collaboration of all agencies concerned and of interested individuals was excellent and much unpublished
information useful to the compilation of this map was generously made available. The chief compiler
especially wishes to express his sincere appreciation for the assistance and cooperation received from all
the members of the geologic map committee. He also wishes to acknowledge the whole-hearted support of Patzen
Wu and S.T. Lu, Director and Deputy Director of the Department of Mines of the Ministry of Economic Affairs,
at all times during the compilation of this map. He is grateful to F.Y. Lin of the same Department, who
acted as liaison officer for the whole project and offered valuable help to the work. He would like to
mention particularly the able assistance of C.H. Wu who was responsible largely for the cartography. The
Mining Research and Service Organization generously provided office space and other facilities for the
compilation and preparation of the map and this report. Thanks are due T.T. Fung, President of the Mining
Research and Service Organization, for his continuing support and help.
Fourteen years have passed since the publication of the 1974 geologic map of Taiwan. During this period,
study and regional mapping of the geology of Taiwan have progressed significantly, and a great body of newly
published data can be used to supplement and revise the 1974 map in a number of critical areas. This is
especially true with regard to the western flank of the Central Range (Hsuehshan Range), where knowledge of
stratigraphy and structure has been greatly improved and updated. Extensive geologic mapping has also been
completed on the Hengchun Peninsula at the southern tip of the Taiwan island. The Coastal Range in eastern
Taiwan is much better understood as a result of advances in theory and interpretative studies of the
structure, sedimentology, and paleontology. Petrographic studies and field investigations of the metamorphic
basement on the eastern flank of the Central Range have also been carried out by both Chinese and foreign
geologists. This work has included detailed analyses of the metamorphic geology, rock chemistry, mineral
chemistry, and radiometric ages of the rocks in this oldest geologic belt of Taiwan. Based on recent
biostratigraphic research and fossil zonation studies, the ages of some major Tertiary formations in the
western foothills have been revised. There is a clear need for all these significant new data to be
incorporated into the general geologic map of Taiwan. The time is thus appropriate for revision of the 1974
geologic map to enhance its utility.
The areas for which pertinent geologic data and information are still lacking are the eastern and the
southern parts of the Central Range. These terrains are characterized by precipitous mountains, dense
vegetation and difficult accessibility. Only scattered geological reconnaissance trips have been made in
most parts of these areas. Substantial revision of the geologic data in those remote areas must be deferred
until more extensive field study in the Central Range is made possible by construction of the proposed
cross-island highways in several critical areas.
The 1974 geologic map of Taiwan was published in two scales: 1:250,000 and 1:500,000. Thus far only the
1:500,000 geologic map of Taiwan has been revised; the 1:250,000 geologic map of Taiwan will be revised at a
later date when more data are available. In this most recent compilation, the writer was again assigned to
be chief editor of the revised map, but no formal geologic map committee was organized. Instead, editorial
meetings were held with a number of experienced geologists who had taken active part in the regional geologic
mapping in various parts of Taiwan during the past ten years or so. This group of geologists met together
several times during 1985 and 1986 to exchange ideas and discuss all essential problems related to the
compilation of this map.
Among the geologists who constantly attended the editorial meetings, the writer is particularly thankful to
Chao-Msia Chen, Hsien-Neng Hu, Chien-Shui Huang, Chao-Chung Lin and Ming-Kuan Tu of the Central Geological
Survey and C.S. Lee (presently chairman of the Department of Earth Sciences of the Taiwan Normal University)
and P.T. Chang of the Energy and Mining Research/Service Organization, ITRI. Their constructive comments and
suggestions have been most helpful during the course of this revision. Some geologic data have also been
furnished by other geologists whose names are acknowledged in the text. Acknowledgement is due to Chia-Yu Lu
for providing the map showing the distribution of gneissic bodies in northeastern Taiwan. Special thanks are
due Neil Lundberg of the Princeton University for his critical review of the English version of this text.
The writer acknowledges with pleasure the assistance of Daw-Long Isaac Jeng, Shyh-Shyan Hsu, Ruey-Chang
Jeng, and W. J. Lo in preparation of the manuscript of this second edition. Ms. Huey-Fen Chen of the Central
Geological Survey helped largely in proofreading. Cartography of the map was efficiently undertaken by F.S.
Lu and H.J. Tsai of the Central Geological Survey. The writer is much indebted to the Central Geological
Survey and the Energy and Mining Research/Service Organization, ITRI for their continuous support and
encouragement and providing all the necessary facilities for this revision.
Editing of the second edition of the 1:500,000 geologic map and of the explanatory text was begun in 1984
with the assessment and screening of all relevant data. Compilation of the map and revision of the text
were completed in 1986, and both the revised map and the revised Chinese text were published in November,
1986.
In this edition, colored photographs illustrating the significant and interesting geological features of
Taiwan replace black and white pictures in the first edition. The writer is most grateful to Hao-Tsu Chu,
Christopher C.K. Fong, Hui-Cheng Chang, Kai-Shuan Shea, Chun-Sun Lee and Shin Wang for the photographs they
supplied from their collections. The writer is especially indebted to Christopher Fong and Kai-Shuan Shea
of the Central Geological Survey who went to the field to take a number of the colorful and meaningful
photographs specifically for this report. The SLAR image of Taiwan printed on the first page was graciously
supplied by W.T. Cheng of the Energy and Mining Research/Service Organization, ITRI.
Most chapters in the second edition of this text have been revised, expanded and updated in view of the new
information and ideas that have been put forth over the past 14 years. The organization of the text has also
been changed from that of the first edition. Instead of discussing the geology of the entire island of
Taiwan by separate topical chapters pertaining to stratigraphy, structure, volcanic activity, tectonism and
others, emphasis in this new edition has been placed on individual geologic provinces. Thus the island of
Taiwan is first divided into a number of geologic provinces or tectonostratigraphic belts, such as the
Central Range, the Coastal Range and others. Then the various topics of stratigraphy, structure and others
in each geologic province are discussed and treated regionally. The writer hopes that, in this way, the
reader may benefit by gaining a thorough understanding of the geologic development of each important geologic
province of Taiwan and the relationships between them. This revision was undertaken in an effort to make this
text more interesting and useful, so that the reader may appreciate more fully the complete picture of the
geology of Taiwan.
The chapter on "General geology and geologic provinces of Taiwan" serves as an overview as well as an
introduction to the general geology of Taiwan. It may be useful to those readers who are unable to read the
entire text but wish an encapsulated summary of the general geologic history and development of Taiwan.
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