Deep crustal seismic surveys 2014-15
Four deep crustal reflection seismic lines have been acquired by the Geological Survey of Queensland (GSQ) from 2014 to 2015 in western Queensland. These new lines, together with seismic surveys collected over the past 10 years, now form a continuous backbone of reflection seismic data (see Figure 1) through one of Queensland's most prospective mineral hosting regions.
Figure 1: Deep crustal seismic reflection surveys in North West Queensland.
The data reveals both shallow and deep structural features in the crust (see Figure 2) and will contribute significantly to the understanding of how tectonic controls shaped Queensland. The processed seismic sections will aid explorers in identifying new potential targets and re-evaluating current interpretations of local mineralisation controls.
The length and orientation of the new transects are given below:
- 14GA-CF1 was acquired in 2014 along main road corridors from Longreach through Winton and Julia Creek, ending north of the Four Ways intersection and covering 670 km
- 14GA-CF2 is north–south-trending, 368 km long and located between Birdsville and Boulia
- 14GA-CF3 and 15GA-CF3 together are 480 km long and run east–west. The line begins west of Boulia and ends in Winton, and links CF1 with CF2.
The new seismic lines were located to help define and investigate large structural features seen in regional airborne magnetic and ground gravity surveys. They will also attract new exploration to these areas and provide a quality baseline of data for explorers.
The seismic surveys hoped to achieve the following specific goals:
- identify a crustal contrast across the Cork fault
- image the structure of the undercover Mount Isa Inlier
- further define the boundaries and stratigraphy of the Millungera Basin
- determine the depth to prospective basement.
The data has already been used by academics and explorers with mineral and petroleum tenures in the area. Interpretation and synthesis of all the seismic and other geophysical datasets is currently being undertaken by GSQ in collaboration with Geoscience Australia.
Seismic images and SEG-Y Data are available online for free through GSQ’s data delivery web portal QDEX Data.
Figure 2: The Cork fault imaged in 14GA-CF1.