The contemporary mineral exploration undertakings of China began as soon as after the success of the Revolution of 1911. Under extremely difficult conditions in the past, the geologists of the older generation put in a lot of assiduous labour and did much useful work for the mineral exploration and development undertakings of their motherland. They investigated the geological conditions and the circumstances of mineral resources in many areas of China, discovered a large number of mineral occurrences and prospecting clues, estimated reserves of 18 varieties of mineral resources and carried out mineral development on different scales, thus laying a certain basis for the subsequent mineral exploration and development. However, the grand development of the mineral exploration and development undertakings was a matter that did not take place until after the founding of the People's Republic of China in 1949.

1.4.1 Main Achievements in the Mineral Resources Exploration of China

Since the founding of the People's Republic of China, thanks to the great concern and attention of the government, there has gradually formed a geological contingent which is composed of geological professionals and workers who are able to bear all hardships and stand hard work and are good at brazing new trails, which involves a complete set of work types of production, including geological survey, topographic mapping, geophysical prospecting, geochemical exploration, exploration engineering, laboratory analysis and testing, airborne remote sensing and electronic computer application and is armed with related perfect, technical equipment and which is capable to perform combined explorations on land, in the air and at sea. Just due to the concerted cooperation and arduous efforts the mineral resources exploration and development undertakings have gained unprecedented great development on a tortuous road and made immense achievements that have attracted world's attention.

Up to the present, China has 171 varieties of mineral resources and more than 200,000 mineral occurrences, of which 20,000 localities have been subjected to explorations in varying degrees. In China, the number of varieties of mineral resources with explored reserves increased from 2 in 1949 up to 154 in 1997, including 8 varieties of mineral energy resources, 54 varieties of metallic mineral resources (5 varieties of ferrous metallic ones, 51 varieties of nonferrous and rare-earth metallic ones and 8 varieties of precious metallic ones), 89 varieties of nonmetallic mineral resources and 3 varieties of other water and gas resources (groundwater, mineral spring water and CO2 gas).

1.4.1.1Mineral Energy Resources   

Mineral energy resources are an important part of China's mineral resources. Mineral energy such as coal, petroleum and natural gas makes up about 93% and 95% in the primary energy consumption structure of the world and China, respectively. Mineral energy is of particularly important strategic significance to the national economic and social development, since it occupies a leading position in the primary energy consumption. China has rich mineral energy resources which are complete in variety and widespread in distribution (Fig. 1.4.1,see the end of the book). The mineral energy resources which are known to have explored reserves in China include the following varieties: coal, petroleum, natural gas, oil shale, rock coal, uranium, thorium and geothermal energy. In this book the stress will be laid on 5 varieties of them: coal, petroleum, natural gas, uranium and geothermals.

1.4.1.2 Metallic Mineral Resources

China's metallic mineral resources are complete in variety, abundant in reserve and extensive in distribution (Fig. 1.4.2,see the end of the book). In China 54 varieties of metallic mineral resources have explored reserves, namely, mineral resources of iron, manganese, chromium, titanium, vanadium, copper, lead, zinc, bauxite, magnesium, nickel, cobalt, tungsten, tin, bismuth, molybdenum, mercury, antimony, platinum-group metals (platinum, palladium, iridium, rhodium, osmium, and ruthenium), gold, silver, niobium, tantalium, beryllium, lithium, zirconium, strontium, rubidium, cesium, rare-earth elements (ytrium, gadolinium, terbium, dysprosium, cerium, lanthanum, praseodymium, neodymium, samarium and europium), germanium, gallium, indium, thallium, hafnium, rhenium, cadmium, scandium, selenium, and tellurium. The mineral resources of the above-said varieties vary in the degree of geological studies and abundance. Some resources are more abundant, such as those of tungsten, molybdenum, tin, antimony, mercury, vanadium, tinanium, rare earths, lead, zinc, copper and iron, while some others are apparently insufficient, e.g. those of chromium and so on.

1.4.1.3 Nonmetallic Mineral Resources

China has abundant nonmetallic mineral resources which are numerous in variety and extensive in distribution (Fig. 1.4.3,see the end of the book). There are 89 varieties of nonmetallic mineral resources that have explored reserves: diamond, graphite, native sulphur, pyrite, rock crystal, corundum, kyanite, sillimanite, andulusite, wallastonite, nitratine, talc, asbestos, blue asbestos, mica, feldspar, garnet, pyrophillite, diopside, tremolite, vermiculite, zeolite, alunite, mirabilite, gypsum, barite, witherite, trona, calcite, Iceland spar, magnesite, fluorite, gemstone, jade stone, agate, pigment minerals, limestone, marl, chalk, dolomite, quartzite, sandstone, natural quartz sand, vein quartz, powdery quartz, natural oilstone, K-bearing sandshale, diatomaceous earth, shale, kaolin, ceramic clay, refractory clay, attapulgitic clay, sepiolitic clay, illitic clay, rectoritic clay, bentonite, siderotil earth, other clays, peridotite, serpentinite, pyroxenite, basalt, amphibolite, gabbro, diabase, andesite, diorite, syenite, granite, pearlite, pumice, nepheline syenite, trachyte, tuff, volcanic ash, cinder, marble, slate, gneiss, peat, salt, potash salt, magnesian salt, iodine, bromine, arsenic, boron, and phosphorus.

1.4.1.4 Outline of Geology and Mineral Resources of the Taiwan Region

N-S trending geological structures are well-developed in the Taiwan region. The Central Range which is located in the middle of the Taiwan Island stretches in the NNE-SSW direction and represents the principal structural trend. Here, the outcropping strata are mainly Cenozoic and the oldest rocks are Permian in geological age. According to the Geological Map of Taiwan, the Taiwan region is divided into 5 geological terrains:

1) Shale-slate terrain in the west wing of the Central Range. This terrain lies in the middle part of the Taiwan Island, belonging to the Central Range zone. It has a NNW-SSE trending structural line and the Lanyang longitudinal fault runs N-S across the terrain. Stratigraphically, Cenozoic Paleogene Oligocene and Neogene Miocene rocks are predominant and lithologically they are quart sandstone, quartzite, quartzose slate, phyllite and black shale containing low-grade coal beds.

2) Terrain of metamorphic complex in the east wing of the Central Range. The terrain is composed of Paleozoic to Mesozoic variegated schist, marble, metamorphic limestone, gneiss and migmatite, which tend to be younger in age westwards.

3) Eastern Coastal Range geological terrain. The terrain is made up of Cenozoic Miocene to Pleistocene marine deposits, which lithologically consist of mudstone, sandstone, limestone, agglomerate, shale and conglomerate. There have occurred several submarine intermediate and basic volcanic eruptions.

4) Western foothill geological terrain. The terrain, located at the west foot of the Central Range, comprises the foothill zone and littoral plain area and extends westward to the Taiwan Straits. Stratigraphically it is made up mainly of Neogene and Quaternary sandstone, mudstone, shale and modern laterite, sand and gravel and it is Taiwan's oil-gas prospective area.

5) Chilung, Tatun and Penghu Volcanic Groups. The Chilung and Tatun Volcanic Groups are distributed in the northern part of Taiwan Island. The Tatun Group is dominated by andesite with a minor amount of basalt, whereas the Chilung Volcanic Group is of quartz andesite. The Penghu Volcanic Group, which is mainly composed of basalt, is distributed in the sea area to the west of the Taiwan Island. The volcanic eruptions occurred in the Pleistocene of the Quaternary.

The Taiwan region is not quite rich in mineral resources and is particularly poor in metallic mineral resources. Altogether 30-odd varieties of mineral resources have been found to be of industrial value. Most of them are insignificant in reserve and poor in quality, and some of them have been depleted as a result of mining. At present, according to geological explorations, there are nearly 20 varieties of mineral resources that are of economic value and are still being mined and utilized. They mainly include coal, petroleum, natural gas, geothermal energy, copper ore, gold ore, serpentinite, dolomite, salt, jadestone, limestone, marble, sand and gravel.

The coal-bearing series of Taiwan is Tertiary Miocene in geological age. Coal deposits are distributed in two major coalfield areas: northern and central, on the Taiwan Island. The northern coalfield area lies in the form of a strip over an area of about 2,000 km2, extending from the coast at the northeast end through Chilung, Taipei, Taoyuan, Hsinchu and Miaoli Counties southwestwards to the right bank of the Taan River. The important coalfields which have been developed, such as the Jianfeng, Longtai, Jianshi, Tianliaokeng, Sanmin and Lifeng coalfields are all concentrated in this area. The central coalfield area is located in the central part of the Taiwan Island and consists of the Chichidashan and Fenghuangshan coalfields in Nantou County, the Alishan coalfield in Chia-i County, etc. The Taiwan region retained remaining explored workable coal reserves of about 170 million tons in 1994, according to the data from the "Mining Department of the Economic Ministry" of Taiwan.

Petroleum and natural gas occur in the Neogene formations. The area to the west of the Central Range is the principal oil-gas province, which consists of 3 oil-gas zones from east to west: the Lushan fold zone, Hsihai Plain concealed structural zone, and outer sea zone. The important oil-gas fields include the Chinshui, Chuhuangkeng, Chutung, Yunling, Bazhangxi, Hsinying and Changkang oil-gas fields. In accordance with the data from the Mining Industry of Taiwan, the Taiwan region of China has petroleum reserves of about 640,000 tons and gas reserves of 16.4 billion m3.

Geothermal occurrences are found throughout the Central Range in the middle part of the Taiwan Island. There are two genetic types: volcanic and non-volcanic. The geothermal occurrences of the volcanic type are represented by the Tatunshan geothermal field; there are over 20 occurrences of the non-volcanic type, mainly including the Wulai, Chingshui, Chingshan, Hoping, Jenai, Juisui and Baolai geothermal fields, of which the Chinkuashih geothermal field in Ilan County is the most famous one. Among them, 9 geothermal fields have been explored by drilling and are estimated to have a power-generating potential energy of 763 MW.

Copper-gold (silver) ore deposits are mainly of endogenic origin. In the Taiwan region such deposits have been found at Chinkuashih, Jiufen, Jimei, Tongshan, etc. The Chinkuashih mining district used to be Taiwan's leading producing district of metallic ores with a mining history of nearly 100 years, but the mining operations there stopped because of the depletion of resources in 1986. The Chinkuashih deposit is an epithermal ore deposit with gold contents in the range of 1.2~4.0 g/t generally and up to 100~1,000 g/t in storm samples and copper contents of 0.2%~0.6%. Based on explorations, it is considered that there exists a possibility of the presence of porphyry copper deposit at the depth. According to the reserve estimates of the deposit by the "Economic Ministry¡± of Taiwan, within a depth of 100 m below the surface there are 5.8 million tons of unexploited low-grade gold ores, containing 7.366 tons of gold and 10 million tons of copper ores. Exogenetic placer gold deposits are found to occur in Hsincheng, the Pingfeng Mountain, the Hehuan Mountain, Huanan and other localities.

Both serpentinite and dolomite deposits occur in the eastern part of the Taiwan Island, extending in the NNE-SSW direction. Serpentinite occurs as intrusive bodies of ultrabasic rocks in the Paleogene Danan'ao Schist Bed and the Lijchi Bed of the Coastal Mountains. Their important occurrence localities are Shoufeng, Wanrong and Yuli in Hualien County, Kuanshan and Fuli in Taitung County, etc. Dolomite occurs in the Danan'ao Schist and is associated with crystalline limestone. The main occurrence areas of dolomite are the Dashui and Chingchang mountain areas with a reserve of 55 million tons and the Mugua Mountain area with a reserve of 10 million tons.

Salt beaches are distributed along the west coast of the Taiwan Island, with Tunghsiao, Lukang, Peimen, Hsikang, Tainan and Wangshan all being sea salt producing areas.

Shanyu jade, otherwise called Taiwan jade, is made up of tremolite and actinolite minerals. The jadestone deposits belong to the contactometamorphic type and occur in the Paleozoic-Mesozoic crystalline schist series. The main occurrence localities are Fengtian and Hsilin of Hualien County, etc.

Limestone deposits are Tertiary and Quaternary in age and mainly occur in the Kuanhsi area of Hsinchu County, Zhentoushan area of Tainan County, Dakangshan area of Kaohsiung County and the Chengkung and Tungho areas in the eastern part of the Taiwan Island.

Marble deposits are distributed in the east wing of the Central Range, extending for over 200 km from Suao of Ilan County in the north to the Chihpen Stream of Taitung County in the south. It is estimated that the marble reserves amount to 78.7 billion tons and the volume of workable marbles is 12.0 billion tons. The important marble occurrence areas are the Hoping, Horen and Hsilin areas of Hualien County, with the Hoping mining area being best-known.

Sand-gravel is the most important mineral raw material of Taiwan Province and it ranks the first in terms of the output value of mineral raw material. Sand-gravel resources are classified into four groups: fluvial sand-gravel, terrestrial sand-gravel, rock fragments and marine sand-gravel. Sand-gravel is produced in all 16 counties of Taiwan Province. The main producing areas are Ilan, Taoyuan, Hsinchu, Nantou, Taichu, Yunlin, Pingtung, Hualien and Rutung Counties.