P5026 Georgetown Airborne Gravity Survey 2024

The Georgetown airborne electromagnetic survey of Northern Queensland was flown between August 14th to 7th November 2024. Airborne gravity data were acquired as an ancillary dataset to the primary airborne electromagnetic (AEM) and magnetic datasets using the NxT™ system, a laser ring gyro strapdown inertial measurement unit (IMU) gravimeter. New Resolution Geophysics Pty. Ltd. (NRG) was commissioned for data acquisition and processing, whilst Geoscience Australia undertook the project management, contract management and quality control on behalf of the Geological Survey of Queensland. The survey was funded through the Queensland Resource Industry Development Plan (QIRDP).

The survey area was centered on longitude 143° 30’ E and latitude 18° 15’ S to the east of Croydon. A total of 59 production flights were flown for a combined total of 11,529.4 line kilometres of data and acquired on 2000 m line spacing at 70 m nominal terrain clearance. Quality control was performed by Geoscience Australia, with a QC report is included here.

The main purpose of the survey was to investigate the feasibility of acquiring gravity data as a secondary dataset for exploration purposes. In addition, the presence of multiple different overlapping gravity datasets would allow direct comparison of different acquisition systems and parameters.

The located data, gridded data and quality control reports are contained within this record. The data will also be released by the Geological Survey of Queensland and can be found at: https://geoscience.data.qld.gov.au/data/gravity/gv106922 .

Survey Name: Georgetown airborne gravity survey, 2024 Datasets Acquired: Gravity Geoscience Australia Project Number: P5026 Acquisition Start Date: 14/08/2024 Acquisition End Date: 07/11/2024 Flight line spacing: 2000 m Flight line direction: East-West (090-270) Total distance flown: 11,529.4 line km Nominal terrain clearance: 70 m Blocks: 1 Data Acquisition: New Resolution Geophysics Pty. Ltd. Project Management: Geoscience Australia Quality Control: Geoscience Australia Dataset Ownership: Geological Survey of Queensland and Geoscience Australia

Included in this release: 1. Point-located Data - Survey Data and Repeat Lines ASCII-column data in ASEG-GDF format with accompanying description and definition files. • Vertical gravity data including the various corrections • Re-sampled free-air and complete Bouguer corrected vertical gravity grids, filtered with multiple 2D low-pass filters - 3,200, 3,800, 4,000 and 5,000 m half-wavelength • Terrain corrections • Digital terrain model

1. Grids Gridded data in ERMapper (.ers) format (GDA2020/MGA zone 54): • Free air with a downline 2.8-kilometer half wavelength Kalman filter (Free Air Anomaly 2800.ers) • Leveled and Micro levelled Free air with a downline 2.8-kilometer half wavelength Kalman filter (Levelled Micro levelled Free Air Anomaly 2800.ers) • Free air with a 3.2-kilometer half wavelength grid filter (Free Air Anomaly 3200.ers) • Free air with a 3.8-kilometer half wavelength grid filter (Free Air Anomaly 3800.ers) • Free air with a 4-kilometer half wavelength grid filter (Free Air Anomaly 4000.ers) • Free air with a 5-kilometer half wavelength grid filter (Free Air Anomaly 5000.ers) • Bouguer Anomaly with a 3.2-kilometer half wavelength grid filter (Bouguer Anomaly 3200.ers) • Bouguer Anomaly with a 3.8-kilometer half wavelength grid filter (Bouguer Anomaly 3800.ers) • Bouguer Anomaly with a 4-kilometer half wavelength grid filter (Bouguer Anomaly 4000.ers) • Bouguer Anomaly with a 5-kilometer half wavelength grid filter (Bouguer Anomaly 5000.ers) • Digital terrain model (Digital Terrain Model.ers) • Complete Bouguer and Terrain Correction 1.0 g.cm³ (Terrain Correction 1.0.ers) • Complete Bouguer and Terrain Correction 2.67 g.cm³ (Terrain Correction 2.67.ers)

2. Reports • Contractor's Data Acquisition and Processing Report • Quality Control Report