Boundary indentification for burnt coal seams in Xinming spontaneous combustion district of Shenfu Coalfiled, Shaanxi
Feng Fu-cheng
photogrammetry and Remote Sensing Corp. of Coal field P.R.C
Abstract
Black / white aerial photographs with visible light (1:35,000) are used as main information source to fulfil aero-remote sensing survey on scale of 1:50,000 in this project. Distribution of burnt rock and ignition boundary of coal seams in Xin-ming district covered an area of 1300.km2 in shen-fu coalfield, shaanxi had been identified (trapped). The author gives an introduction to the methodology and results of burnt coal area investigation by means of remote sensing. Target of the investigation is an extinct-burnt area. The first task of the study started with basic geological characteristics investigation is to divide marco-lithotype of burnt rocks, determine its forming epoch and make approach to the mechanism of its genesis. The second task of the study is to establish preliminary interpreting indices by means of studying image fratures of burnt rock and ignitation boundary, which is carried out in a known area selected in the light of existed data. The third task of study is to complete the remote sensing investigation for burnt coal boundary all over the district, to replenish, modify, and perfect the original interpreting indices. During the investigation, interpretation was combined with survey; remote sensing was combined with concernments are fulfilled through borehole examination.
Shen-fu coalfield is worldwide famous for its enormous coal-bearing area, abundant reserves, good coal quality and advantageous mining-technical conditions. It has become one of the important coal bases for exploration and development. However spontaneous combustion in most coal seam outcrop iead to such an extensive distribution of burnt coal, which produced a lot of serious difficulties for coal resources exploration and development.
Using conventional drilling method to identify the boundary of spontaneous district usually need a long period and high cost. The effort of magnetic survey may be excellent, but it is often restricted by some economic or technical conditions. Hence, in this project, we applied black/ while aerial photographs with visible light to aero-remote sensing survey on scale of 1:50,000 in Xin-ming district of Shen-fu coalfield, and identified the boundary of spontaneous combustion area. The final result of the work fulfilled accuracy requirements.
General description of the district
Xin-ming district is located at north eastern part of the loessial plateau in north Shaanxi, which is subordinated to Shen-mu county and Fu-gu county of Shannxi province with an area of 1300 km.
The main strata cropped out are Mesozoic including young-ping formation of Triassic (T3y), Fuxian formation (J1f), Yanan formation (J1-2y) of Jurassic, and Cenozoic including Tertiary (N), Quarternary (Q).
Yanan formation with toal thickness of 235m is the main coalbearing strata in the district. It consists of 5
-1 coal beds. Minable coal seams are numbered 1
-2, 2
-2 ,3
-1 , 4
-3, 5
-1 from top to bottom. Thickness of those are respectively 0-1.7m for 1 (with serious regional disintegration), 1.14m for 2
-2, 1.92m for
3
-1, 0.78 for 4
-3 and 3.32m for 5
-1 spontaneous combustion, which formed extensive distribution of burnt rocks.
In the district, all of the coal rank belong to long flame coal (high-volatile metalignitous coal) with low ash, low suifur, and low phosphorus, Tectonics in the district is rather simple, strata occur horizontally with dip angle of 2-5.
