Sains Malaysiana 46(11)(2017): 2109-2118

http://dx.doi.org/10.17576/jsm-2017-4611-11

 

The Application of Airborne Geophysics Data for Rapid Regional Geological Mapping in Northwestern Angola

(Aplikasi Data Geofizik di Udara untuk Pemetaan Geologi Serantau di Barat Laut Angola)

 

HONGRUI ZHANG^1,2*, PENGFEI JIA², XU ZHANG² & ZHIGANG WANG²

 

¹Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China

 

²CITIC Construction Co., Ltd., Beijing 100027, China

 

Received: 29 January 2017/Accepted: 10 June 2017

 

ABSTRACT

Airborne prospecting (spectrum, magnetics) measurement is an effectively auxiliary approach for geological mapping. It effectively measures the magnetic field characteristics and the surface contents of the most common three radioactive elements (K,eU and eTh) of nature in the research area. Given the significant diversities of magnetic characteristics and the radioelements’ contents of different lithological units, these can be applied into the mapping of shallow overburden area. Ternary MAP is a compound imaging technology, providing the radioelements contents a simultaneous display on the same pixel. Based on colour differences, this technology can identify different lithologies and clithofacial changes in the same lithological unit effectively in a certain area. With aeromagnetic data conversion and integrated spectrum images, a good effectiveness of 1:250,000 lithological-structural mapping has been achieved in the research area of Northwestern Angola.

Keywords: Aeromagnetics; data processing; rapid geological mapping; spectrum; 1:250,000

 

ABSTRAK

Pengukuran prospeksi (spektrum, magnetik) di udara adalah pendekatan tambahan yang berkesan untuk pemetaan geologi. Ia secara berkesan mengukur ciri medan magnet dan kandungan permukaan tiga elemen radioaktif (K, eU dan eTh) yang paling biasa di kawasan penyelidikan. Memandangkan ciri kepelbagaian magnetik yang ketara dan kandungan radiounsur daripada unit litologi berbeza, ini boleh digunakan dalam pemetaan kawasan tebukan cetek. Ternari MAP adalah teknologi pengimejan kompaun, memberikan kandungan radiounsur suatu paparan serentak pada piksel yang sama. Berdasarkan perbezaan warna, teknologi ini dapat mengenal pasti pelbagai lapisan dan perubahan klitomuka dalam unit litologi yang sama secara berkesan di kawasan tertentu. Dengan penukaran data aeromagnet dan imej spektrum bersepadu, keberkesanan yang baik 1: 250,000 pemetaan struktur litologi telah dicapai di kawasan penyelidikan Barat Laut Angola.

Kata kunci: Aeromagnet; pemetaan geologi yang cepat; pemprosesan data; spektrum; 1: 250,000

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*Corresponding author; email: zhhr2214@163.com