Lawn Hill Platform and Leichhardt River Fault Trough measured stratigraphic section online GIS

This GIS web browser contains stratigraphic information from the southern flank of the Murphy Inlier, Lawn Hill Platform and Leichhardt River Fault Trough in the Western Succession of the Mount Isa Block. The principal lithostratigraphic units covered by this dataset include the Surprise Creek Formation, Mount Isa and McNamara Groups. The images are pixilated versions of those contained on CD Records AGSO Record 1999/10, AGSO Record 1999/15, GA Record 2002/3. The data contained on the CD's is more comprehensive, at a better resolution and also contains cross sections that are not available over the web. No drill hole data is supplied in this viewer. The data compiled for this viewer was collected during the course of the NABRE, AMIRA P552 and pmd*CRC projects. The respective CD's also provide measured sections at different scales with slightly varying information available at 1:400, 1:1000, 1:2500 and 1:5000 scales. The information at each scale is slightly different. Plot files ready for printing also accompany the measured sections. 
Each of the measured sections contains primary observational data (grainsize, lithology, bed thickness, sedimentary structure and gamma ray curve) map-based lithostratigraphic units as shown on the 1:100,000 geological sheets, interpreted facies and sequence stratigraphic surfaces. 
Sections were measured using a Jacobs Staff and Abney Level and the rocks were marked in 1.5 m intervals of true thickness. Gamma ray data was collected at either 50 cm or 75 cm intervals of true thickness using hand-held Scintrex GRS 500 spectrometers that measured total gamma ray counts. A beryllium standard was used to calibrate each spectrometer. Each machine was calibrated at intervals of two to three hours. Each gamma reading was averaged over an interval of ten seconds. 
Outcrop discontinuities prevented the collection of stratigraphic data in a line of continuous section. As a result most of the sections present in this data set comprise a series of segments combined to form a single composite section. The single sections were all measured within a radius of several kilometres of each other. Individual sections were spliced together at prominent marker beds (outcrop tracing of strata), or by the use of overlapping gamma ray curves in conjunction with facies descriptions. Section locations shown in the web browser depict the base of each composite section. Grid coordinates for the base each composite section can be found in the header block of the appropriate section. 
The geological maps used in this web browser depict the approximate position of supersequence boundaries. Not all the geology for the region has been included and only the geology relevant to the measured sections has been used. The supersequences provided are based on the most appropriate lithostratigraphic boundaries and no new geological polygons have been created. It should be noted that the Torpedo Creek and Warrina Park Quartzites have been placed in the Prize Supersequence. However, we acknowledge that due to mis-mapping of these sand bodies the Torpedo Creek and Warrina Park Quartzites from the basal part of the Gun Supersequence at some locations.

Tags: AU-SA, Earth Sciences, GIS, GIS Dataset, Published_External, Regional, geology, stratigraphy
Organization: Geoscience Australia Data