| Popis: |
The aim of constructing 3D computer models of outcrops of the Mount Messenger Formation using unmanned aerial vehicle (UAV) drone technology was to enable better visualization and potential for analysis of deep-water sedimentary systems in Taranaki Basin, New Zealand. The Late Miocene-aged strata crop out along the north Taranaki coast of western North Island, New Zealand. The Mount Messenger Formation sandstone and siltstone beds are outstanding examples of deep-water sedimentary strata. These strata can be observed in outcrop sections, as well as in offshore drillholes (wireline logs) and in seismic reflection data acquired immediately offshore of the north Taranaki coastal section. In previous research undertaken on the Mount Messenger Formation in North Taranaki Basin, geologists used photographs and coupled these with observations and descriptions of strata in the field. Modern UAV drone technology now enables 3D perspectives to be obtained of outcrop sections, which greatly improves geometrical analysis of the rocks. This type of analysis, coupled with mapping of seismic reflection data in the immediate offshore area has enabled us to better understand the nature of Mount Messenger Formation deep-water sedimentary strata and to interpret the associated paleogeography with implications for energy resource exploration and evaluation.Using UAV drone photogrammetry, we acquired ∼3000 images of the Mount Messenger Formation outcrop at four locations along the north Taranaki coast. Drone surveys were conducted using a real-time kinetic (RTK) global positioning system (GPS) for accurate geolocation. The surveys were conducted on a DJI Phantom 4 drone, with a focal length of 24 mm with a 20-megapixel resolution. Survey images overlapped by 80–90%. The drone work adhered to the rules and regulations of the Aviation Security Service and the University of Waikato, New Zealand. Images were captured using programmed flight paths where the drone faced the outcrops at distances ranging from ∼3–7 m.3D computer models were constructed using Pix4Dmapper version 4.4.12 to generate dense 3D point clouds, digital surface models (DSMs), triangle meshes, and orthomosaic images of the outcrops (i.e., 3D models). Once the 3D computer models of the outcrops were constructed, they were exported out of Pix4Dmapper as ArcGIS Scene Layer Package format (.slpk) and loaded into ArcGIS Pro version 3.0.3 for further analysis.The 3D computer models comprise a rich and valuable scientific dataset that can enhance geological analysis of sedimentary strata beyond the capabilities of photographs and manual fieldwork. These models allow desktop analysis of the geology and “virtual fieldwork” by imaging areas that are commonly inaccessible on foot due to their high elevation above ground level, location in rugged and steep terrane, as well as periodic intertidal flooding. This electronic geological dataset is stored in commonly used spatial format and plain-text ASCII files, allowing the preservation of geological data in digital records, especially when the outcrops are prone to erosion and cover by vegetation. The drone model dataset can be reused by the scientific community for virtual geological fieldwork, as petroleum and water reservoir analogues, as well as for research on coastal, environmental and geotechnical topics. |
