The Preliminary Study On The Geological Response Of The Cosmic Gamma-ray In The Airborne Gamma-ray Spectrometry

The airborne gamma-ray spectrometry is a direct looking for uranium and otherradioactive ore and potash mineral exploration techniques.It is able to adapt to thecomplex conditions of measurement.It has some significant advantages such as goodresults, high efficiency and low cost. China has carried out a large number ofmeasurements in airborne gamma-ray spectrometry. It has been widely used in oil andgas exploration and solid mineral resources exploration and environmental surveys.This thesis has got financial support by National “863” high-tech researchproject:“Research of airborne gamma-ray spectrometry exploration system”(Serialnumber of the project:2006AA06A207). The main contents are the theoreticalanalysis of the impact factors of the cosmic gamma-ray which was measured by theairborne gamma-ray spectrometry and interference corrections. Combined with theproduction of test cases from AGS-863airborne gamma-ray spectrometerexploration system in a surveyed area in Inner Mongolia, the rusults of the cosmicgamma-ray has been data processed and statistical analysised. Combined with thegeological conditions, it gets a preliminary study at geological response of the cosmicgamma-ray which was measured by the airborne gamma-ray spectrometry spectrum.Mainly following results are obtained:1.It summarizes the domestic and international airborne gamma-ray spectrometrymethods and techniques.Based on the analysis of the impact factors of the airbornegamma-ray spectrometry and absorbed the latest research results,it analyzes theimpact factors of the cosmic gamma-ray which was measured by the airbornegamma-ray spectrometry.2.Combined with the production of test cases from AGS-863airbornegamma-ray spectrometer exploration system in a surveyed area in Inner Mongolia, therusults of the cosmic gamma-ray has been dynamic calibrationed and heightcorrected. 3. Using data grid, it preprocesses the raw data of the cosmic gamma-ray fromthe airborne gamma-ray spectrometry.4. In order to study the relationeship between the distribution regular pattern ofthe rusults of the cosmic gamma-ray and flight altitude, the rusults of the cosmicgamma-ray has been statistical analysised. Mainly following results are obtained:The date of the cosmic gamma-ray from the selected area was unimodal normaldistribution,mainly between190and230cps.The average value is210.7cps and thestandard deviation is20.23.The date of the cosmic gamma-ray has a few of high valueareas,mainly centralized in the southeast of the selected area. Combined with the1:200,000geological map,this area is mainly made up by permian siltstone、slate andcarboniferous gabbro.The low value areas are distributed widely and situated in thenorthwest of the selected survey area. Combined with the contour map of the flightaltitude,it has a small ups and downs of the flight altitude and the area. The contourmap of the flight altitude also has a small area of high value.It mainly centralized inthe southeast of the selected area. Combined with the actual situation of the nationalgeography of the survey area,it is related to that the undulatinl topography is large ofthis area.5. Based on the existing geological maps，according to the statistical analysis ofthe cosmic gamma-ray date which was classified by stratigraphic and lithologic,weget a data parameter table about the survey area lithology aerial gamma ray spectrumcosmic data.It provides the basis for the study which was pretended to study thedifferent stratigraphic units or specific radioactivity of the rock mass characteristicsand geological structure by using the date of the cosmic gamma-ray.1) Both the date of the cosmic gamma-ray and the date which was classified bystratigraphic and lithologic from the whole selected survey area are unimodal normaldistribution.2) The average value of the date which was classified by stratigraphic andlithologic is close to that the average value of the the cosmic gamma-ray date.Veryfew lithologic performs abnormal at the average value,because of the differentradioactive characteristics at the lithology and the statistical error.3) Statistical results show that most of the stratigraphic units’s radioactivecharacteristics are conformed to the statistical regularities. Further validate the resultsis accurate and reliable which was from the the airborne gamma-ray spectrometry.