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Regional Geology Division
Outcrop of a fault at Tachichiao, Peikanghsi, Kuohsing.
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Fundamental geological survey and mapping constitute the major responsibility of the Regional
Geology Division. Geologic map sheets provide fundamental geologic information covering the entire
territory of Taiwan. Through geologic mapping, often new discoveries are made and new ideas are advanced.
The preparation of 1:50,000 geologic map sheets is one of the major duties of the Central Geological Survey.
These map sheets are roughly 675 Km2 in areal extent. To produce one such map sheet, meticulous field
surveying and mapping is first executed. This is followed by careful indoor data processing.
During this period, support is provided by petrologists, mineralogists, and paleontologists from the
various divisions. The final map sheet is an integration of efforts and cooperation from all the geologists
involved.
Geological and structural investigation of the Central Range is another major project of the Regional
Geology Division. The precipitous mountains are mostly inaccessible. Working in the Central Range
is thus a major challenge to most geologists. Through field mapping and related aerial photo-geological
techniques, some of the problems are beginning to be resolved.
Taiwan is straddling on one of the world's major earthquake zones. Active fault investigation is another
topic research of the Regional Geology Division.
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COMPILATION OF 1:50,000 GEOLOGICAL QUADRANGLE MAPS OF TAIWAN
Field data are supplemented by aerial photos and remote sensing imagery interpretations.
This is especially helpful in deciphering regional geologic structures.
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Geologic maps can accurately show the distribution of regional stratigraphy and geologic structures.
It provides basic and crucial data for geoscientific research, land-use planning, economic development
and engineering construction, and resources exploration. The 1: 50,000 geological quadrangle maps are
compiled by geologists from both the CGS and other geologic institutions under the supervision of the
former. There are seventy-six map sheets that cover the island of Taiwan and the surrounding islets.
Geologists of the CGS have devoted much effort to this vast and important project. Compilation of a
geological quadrangle is based on data available from previous workers and data currently obtained from
field mapping and subsequent laboratory work. The draft map and the explanatory text are then critically
reviewed and revised. After that, the map including the explanatory text is formally published.
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The research of active faults is one of the important
projects of the survey.
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INVESTIGATION AND RESEARCH OF REGIONAL GEOLOGY
The stratigraphy and structure of the Backbone Range and active faults of Taiwan are the major research
projects conducted by geologists of the Regional Geology Division.The stratigraphy and structure of the
Backbone Range is a long-term project aimed at unraveling the geologic and structural characteristics
and the history of mountain building in both the Central Range and the Hsuehshan Range.
The investigation of active faults is also a long term project started by collecting past available
information and supplemented by current field investigations. The medium term target of this project
is the compilation of 1:100,000 maps of active faults in Taiwan. This map will provide useful information
for land use planning, earthquake hazard evaluation and prevention.
A number of short-term projects that are in close connection with the above-mentioned ones are also being
conducted. These include research projects sponsored by the National Science Council and projects under the
auspices of the Ministry of Economic Affairs.
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INVESTIGATION AND RESEARCH OF REGIONAL GEOLOGY
The main interest of the stratigraphic research is in the establishment and correlation of lithologic units
in regions. In paleontological research, fossils are identified and their chrono-logical and spatial
distribution defined, which provides a basis for the establishment of biostratigraphic formations,
correlation of lithologic formations and the study of paleo-sedimentary environments.
The tectonic setting of Taiwan is unique and characterized by rapid facies change. Stratigraphic correlation
depends very much on fossils like calcareous nanno fossils and foraminifera, occasionally on mollusks,
corals, sea urchins, and terrestrial mammals. The current stratigraphic research project is focused on
the Plio-Pleistocene mudstones and coral limestone in the southwestern foothill area. Paleontologists
also assist in identification of fossils and stratigraphic correlation in the Backbone Range where a
quadrangle-mapping project is currently undertaken.
A biostratigraphic study is in the Tainan-Kaohsiung hilly area and detailed mapping of the limestone in
the Kaohsiuang area is the current major research of the division. To date, stratigraphic and
paleontological studies on the limestone in areas of Liushuang-Tsengwenhsi, Hsinhua-Kuangmiao, Chishan,
and Panpingshan have been completed. Future study will focus on some type sections of Tertiary strata in
north, central, and south Taiwan so as to systematically establish standard lithostratigraphic and
biostratigraphic successions of Taiwan.
An electron microscope laboratory is set up for research in different fields including micro-paleontology,
mineralogy and petrology. It is equipped with a Hitachi S-2500 scanning electron microscope with a maximum
magnification 200,000. This SEM is superior to ordinary optical microscope in micro-paleontological
identification and clay mineralogical studies.
- Globorotalia siakensis LeRoy
- Globorotalia siakensis LeRoy
- a-b. Globigerinella aequilateralis (Brady)
- Globoquadrina dehiscens (Chapman, Parr and Collins)
- Dentoglobigerina globosa Bolli
- Globorotalia siakensis LeRoy
- Globorotalia siakensis LeRoy
- Globorotalia menardii (Parker, Jones and Brady)
- Globoquadrina dehiscens (Chapman, Parr and Collins)
- Dentoglobigerina globosa (Bolli)
- Sphaeroidinellopsis seminulina (Schwager)
( back to Organization )
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