1. Mining Geology
(1) tectonic background
This area is located in the core of Qianxi continent south of Yanshan rift zone (secondary structural unit) of China-Korea paraplatform. Structural deformation is mainly faults and folds. The large-scale faults in this area include Miyun-xifengkou deep fault, Gu 'an-Changli concealed deep fault and He Qinglong fault. However, there are three periods of folds that have obvious influence on the basement structural pattern in this area: Qianxi fold, Fuping fold and Wutai-Lvliang fold.
The iron mine in Zunhua-Jianchangying area, Hebei Province is located in the southwest of Sijiaying-Changling metallogenic belt, and the Gu 'an-Changli fault zone passes through the southeast of this area, with uplift in the north and Quaternary depression in the south. Its basement consists of Archean and Proterozoic metamorphic supracrustal rocks and metamorphic plutonic rocks. According to the differences of original rock formation types and geological transformation of metamorphic rock series, two metamorphic rock areas can be roughly divided. It is basically bounded by the NE-trending fault to the north of qinglong river, with Zunhua-Qian 'an intermediate and high-grade metamorphic rock area in the west and qinglong river granite-greenstone belt in the east.
(2) mining strata
The ore-bearing strata in this area are mainly Qianxi Group (Ar2Q), Luanxian Group (Ar3L) and Zunhua Group (Ar3Z), followed by Zhuzhangzi Group (Ar3Z), and Caozhuang Group (Ar 1c). No formed deposits have been found.
The most important and only ore-bearing stratum in this area is Luanxian Group, which is distributed in Luanxian, lulong county and Luannan counties, and is divided into Yangshan Group in the lower part and Luzhangzi Group in the upper part. Xiayangshan Formation is the most important ore-bearing stratum in eastern Hebei, with the most mineral resources, such as Sijiaying-Dajiazhuang Iron Mine in Luanxian County.
The lithology of Yangshan Formation is mainly biotite plagioclase granulite, with garnet biotite granulite, biotite amphibole granulite, amphibole granulite, rhyolite granulite, granulite, etc. Shi Ying containing amphibole and magnetite. Some of them are intercalated with schist and lenticular dolomite marble.
(3) Magmatic rocks
Magmatic activities in Zunhua-Jianchangying iron mine area in Hebei Province are dominated by Mesozoic, in which Indosinian is dominated by magmatic intrusion, and Yanshan is both volcanic eruption and magmatic intrusion. The Indosinian intrusive rocks are mainly Dushan Ultraunit (T3DS), represented by Dushan rock mass in Qinglong County, with an exposed area of more than 300 km2, which is a large compound bedrock. According to the characteristics of magmatic evolution, it can be divided into five rock units from early to late, namely, Xiaoqing fine-grained diorite → Shichengzigou porphyry diorite → Wudaoling medium-fine adamellite → Shizhangzi medium-coarse adamellite → Yangshugou medium-coarse adamellite. Each unit is nested in a space. The Yanshanian volcanic-intrusive rocks can be roughly divided into four volcanic-intrusive cycles: early Jurassic, middle Jurassic, late Jurassic and early Cretaceous.
In a word, Yanshanian magmatic rocks are relatively developed in this area, which is beneficial to the formation of endogenetic iron ore. For example, contact metasomatic iron deposits can be found in the contact zone between Xiaoyingzi superunit and Shouwangfen superunit and in the carbonate strata of Yuanguyu.
2. Screening and collection of physical geological data
1)NTZK00 1 drilled full-hole core. The hole is drilled in the pit, with a hole depth of 100 1.54m, a final hole inclination of 90, a total hole core length of 893.37m and a core recovery rate of about 89.2%. Good prospecting prospect. Magnetite timely sandstone is found at the hole depth of 802.85 ~ 881.5m. Magnetite is unevenly distributed in bands, and its content varies greatly, with an average of 10% ~ 50%. The hole depth is 902.39 ~ 9 19.4 1 m, the magnetite content is 10% ~ 30%, the reaction time is 40% ~ 80%, and chlorite 10% ~ 30%.
2)DHZK00 1 drilled whole hole core. The hole is drilled in the pit, with a hole depth of 1250.09m, a final hole inclination of 90, a full hole core length of 1075.08m and a core recovery rate of about 86.0%. This ore was found very well. Magnetite was found at the hole depth of 739.5438+0 ~ 784.05 meters, with an average of 30% ~ 40% magnetite and fine pyrite.
The two boreholes NTZK00 1 and DHZK00 1 have complex ore types, many useful minerals and high content. It is found that there are various types of surrounding rock and surrounding rock alteration in the mining area, which is a very representative borehole in the mining area and fully meets the basic requirements of borehole acquisition.
3. Relevant information
1)NTZK00 1 borehole geological record;
2)DHZK00 1 borehole geological records;
3) Plan of Songdaokou;
4) Geological map of Sigezhuang-Songdaokou;
5) Plan of Sigezhuang;
6) Brief introduction of Duhaotuo Iron Mine (electronic version);
7)NTZK00 1 borehole histogram;
8)DHZK00 1 borehole histogram.