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European Journal of Applied Sciences – Vol. 10, No. 6
Publication Date: December 25, 2022
DOI:10.14738/aivp.106.13391. Chao, Y., Yin, J., Yin, Y., Xiang, S., Shi, H., & Wang, J. (2022). The Paragenetic Stage of the Dongping Gold Deposit in the Northern
Margin of the North China Platform. European Journal of Applied Sciences, 10(6). 38-47.
Services for Science and Education – United Kingdom
The Paragenetic Stage of the Dongping Gold Deposit in the
Northern Margin of the North China Platform
Yuhong Chao
Engineering Geology Brigade of Jiangxi Bureau of Geology
658 Jiefangxilu Road, Nanchang, Jiangxi Province 330002, China
Jianzhao Yin
College of Earth Sciences, Jilin University, Changchun 130061, China
Yuhan Yin
Xuchang Electrical Vocational College, Xuchang 461000, China
Shoupu Xiang
Silvercorp Metals Inc., Suite 601-Building 1, China View Mansion
#A2 East GongTi Road Chaoyang District, Beijing 100027, China
Hongyun Shi
Orient Resources Ltd., Richmond, B.C., Canada V7E 1M8
Jiapeng Wang
Geophyrical & Geochemical Exploration Brigade of Jiangxi
Province, 229 Yunqing Road, Nanchang, Jiangxi Province 330009, China
ABSTRACT
The Dongping gold mine, located at the northern margin of the North China
Platform, is one of the few large-scale gold deposits in China related to alkaline
complex intrusions. In view of this, in-depth dissection of its causes is not only of
geological theoretical significance, but also helps to find more similar gold
resources under similar geological background, so as to benefit local people. To
achieve the above goals, it is necessary to accurately grasp the paragenetic process
of the deposit, that is, its paragenetic period and paragenetic stage. Through
detailed field and laboratory research, the authors of this paper concluded that the
formation of the Dongping gold deposit was the result of multi-stage paragenetic
process. Specifically, the formation of the Dongping gold deposit has gone through
the following four paragenetic stages, namely (from early to late): Milky white
quartz (Q1)-potassium feldspar (K1)-coarse grained pyrite (cgPy) stage, Grey white
quartz (Q2)-brick-red potassium feldspar (K2) stage, Potassium feldspar (K3)-quartz
(Q3)-polymetallic sulfide stage, and Calcite-chert (Q4)-barite stage. Among them, the
third stage, that is, the Potassium feldspar (K3)-quartz (Q3)-polymetallic sulfide
stage, is the most important paragenetic stage, marking the climax of the gold
mineralization of the deposit.
Key words: paragenetic stage; mineralization; Dongping gold deposit; the North China
Platform
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Chao, Y., Yin, J., Yin, Y., Xiang, S., Shi, H., & Wang, J. (2022). The Paragenetic Stage of the Dongping Gold Deposit in the Northern Margin of the
North China Platform. European Journal of Applied Sciences, 10(6). 38-47.
URL: http://dx.doi.org/10.14738/aivp.106.13391
INTRODUCTION
The Dongping super-large gold deposit is located in Dongping Village, Sitaizui Township,
Chongli County, about 11 kilometers southeast of Chongli County Seat. The mining area is 11.2
kilometers long from east to west, 6.5 kilometers wide from north to south, and covers an area
of 64.7 square kilometers.
The mine was established in 1986, with a daily processing capacity of 150 tons of ore. In 1990,
the production was expanded to 300 tons per day, and it was further expanded to 800 tons per
day in 1995. In 2005, the Zijin Mining Corp. controlled the Dongping gold mine and expanded
the daily processing capacity to 2,500 tons per day or 825,000 tons of ore yearly, with an annual
output of 2.4 tons of gold.
By studying the interpenetration and cutting relationship between ore-bearing vein bodies in
different ages, this paper attempts to reveal the paragenetic period and paragenetic stage of the
Dongping gold deposit.
REGIONAL GEOLOGY
The Dongping gold mine is located at the northern margin of the China-North Korea Platform,
on the south side of the junction of the Inner Mongolian geo-axis and the Yanshan folding zone,
and is about 8 km away from the Chongli-Chicheng deep fault in the north.
The exposed strata in the mining area are mainly metamorphic rocks of the Archean Sanggan
Group, and the lithology is mainly amphibole gneiss, which is distributed to the south of
Zhaoshanwa-Nanping Village in the southwest of the mining area. The overall trend of the strata
is 300 degrees, inclined to the northeast, and the inclination angle is 50-70 degrees. The rock
types are amphibole plagiogneiss, plagioclase amphibolite, biotite schist and granulite, which
are metamorphosed from basic volcanic rocks1-4.
The strata of the area, especially the Archean metamorphic basement, experienced multiphase
tectonic activities including three phases of folding that formed the east-western hinge
synclinorium, the overturned NNW-NWW hinge synclinorium, and the NW-NWW hinge
synclinorium.
The igneous rocks in the mining area mainly include Hercynian alkaline magmatic rocks and
Yanshanian granites. The Hercynian Shuiquangou alkaline complex is exposed in the northern,
central and eastern parts of the mining area, and its eastern end is intercepted by Wenquan
porphyritic granite. The intrusive strikes 290 degrees, dips to both sides and the dip angle is
75-80 degrees. The intrusive is 54 kilometers long and 4.0-8.5 kilometers wide. The intrusive
are mainly alkaline feldspar syenite and quartz alkaline feldspar syenite. The intrusive is closely
related to gold mineralization and numerous different sizes of gold deposits have been
discovered within and/or around it. The Yanshanian granites are distributed in the Yaowanzi- Shangshuiquan area, and intrude into the Archean metamorphic rocks, syenite, and hornblende
monzonite.
The well-developed faults include east-west-, northwest- and northeast-striking faults. Of
these, the east-west-striking Chongli-Checheng giant fault, also the boundary between the Inner
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European Journal of Applied Sciences (EJAS) Vol. 10, Issue 6, December-2022
Services for Science and Education – United Kingdom
Mongolian geo-axis and the Yanshan folding zone plays an important role in the formation of
gold deposits1-4.
MINE GEOLOGY
The Dongping gold ore field trends north-west. It includes 9 ore belts from west to east, and the
ore belts trend NNE-NE. There are 69 gold ore bodies distributed in 9 ore belts, among which
the main bodies are #1-70, 1-2, 1-3, 1-22, 1-26 and so on. The veins are tens to hundreds of
meters long, and the longest is nearly a thousand meters2-5.
The ore-conducting structure in the mining area is the F16 fault, which is distributed near the
intrusive contact zone in the southern part of the mining area and is a part of the regional deep
fault. The main ore veins in the mining area are all on the hanging wall of the fault. There are
also three groups of faults in the mining area: NNE, NW, and NEE. Among them, the north- northeast-trending fault is the main ore-bearing fault in the mining area, with a strike of 0°-20°,
a north-west dip, and a dip angle of 40°-50° degrees. The NW-trending fault is also the main
ore-bearing structure in the area, with a strike of 290°-340°, a dip of 25°-48° to the southwest.
The NE-trending fault strikes 50°, dips to the north-west, and the dip angle is 45°. The gold
mineralization of this group of faults is poor.
The #1-70 ore body has a total length of 1400m, a width of several tens of meters to more than
500 meters, and a maximum oblique depth of 820m. The ore bodies are hosted in the
silicification-potassium altered syenite, the alteration zone trends NNE, dips westward, and the
dip angle is medium. Gold grades of the ore body range from a few grams per ton to as high as
hundreds of grams per ton.
The ore body #1-1 is distributed between exploration lines 11-12, with a dip of 280°, a dip angle
of 20° to 56°, a length of 597m, a depth of 600m, an average thickness of 2.4m, and an average
gold grade of 9.91g/t.
The #70-5 ore body is distributed between the 3-31 exploration lines, with a dip of 320°, a dip
angle of 24°-35°, a length of 1100m, an extension of 600m at depth, an average thickness of 5-
106m, and an average gold grade of 4.6g/t.
Wall rock alterations mainly include potassium feldsparization and silicification, followed by
pyritization and sericitization, as well as carbonation, barite, and kaolinization. The first four
alterations are closely related to gold mineralization.
The Dongping gold deposit is an alkali complex intrusion-related style gold mineralization
discovered in the alkaline complex in the northern margin of the North China Platform in the
1980s. The ore is sulfide-poor and telluride-rich type. The ore minerals of the Dongping gold
deposit include natural gold, pyrite, chalcopyrite, galena, magnetite, hematite, limonite, bornite,
pyrrhotite, lead telluride, silver telluride, gold telluride, native gold, bismuth telluride,
tetradymite, and bismuth telluride etc. The main mineral combination is pyrite-chalcopyrite- various tellurides-native gold-calaverite-hessite. Native gold accounts for 90% of the total gold,
and the gold fineness is 934-978. Gold is dominated by medium and coarse grains, and cracked
gold and interstitial gold account for more than 80%2-5.