Exploring for the Future – Interpreted Horizons of the South Nicholson Seismic Survey.

Exploring for the Future (EFTF) is an Australian Government program led by Geoscience Australia, in partnership with state and Northern Territory governments. The first phase of the EFTF program (2016-2020) aimed to drive industry investment in resource exploration in frontier regions of northern Australia by providing new precompetitive data and information about their energy, mineral and groundwater resource potential (Carr et al 2018).The South Nicholson Basin and immediate surrounding region is situated between Paleo-Mesoproterozoic Mount Isa Province and McArthur Basin. Both the Mount Isa Province and McArthur Basin are well studied. By contrast, the adjacent South Nicholson region is less studied, and contains rocks that are mostly undercover, for which the basin evolution and resource potential is not well understood. To address this gap, the L210 South Nicholson Deep Crustal Seismic Survey was collected in 2017 in the region between the southern McArthur Basin to the Mount Isa western succession, crossing the South Nicholson Basin and Murphy Province, providing a fundamental data link across these regions (L210 South Nicholson Deep Crustal Seismic Reflection Survey). The primary aim of the survey was to investigate areas with a low measured gravity response in the region to determine whether they represent thick basin sequences, as is the case for the nearby prospective Beetaloo Sub-basin. The interpretation of this survey led to the discovery of a new basin, the Carrara Sub-basin, coinciding with a gravity low in the south-eastern South Nicholson Basin Region.This data set contains an exported set of XYZ points from interpreted horizons (Carr et al 2019) on the South Nicholson Seismic Survey (L210) in both two way time (TWT ms on PreSTM_17ga lines) and depth (m) re-interpreted on depth indexed PreSDM_17GA lines. The coordinate reference system for this dataset is WGS 1984 Australian Centre for Remote Sensing Lambert. Seismic reference datum is 350 m. The seismic reference datum are described in the EBCDIC headers of the SEGY files for each of the survey lines.Carr, L.K., Southby, C., Henson, P., Costello, R., Anderson, J.R., Jarrett, A.J M., Carson, C.J., Gorton, J., Hutton, L.J., Troup, A., Williams, B., Khider, K., Bailey, A. & Fomin, T. 2019. Exploring for the Future: South Nicholson Basin geological summary and seismic interpretation. Record 2019/21, Geoscience Australia, Canberra. http://dx.doi.org/10.11636/Record.2019.021Carr, L.K., Southby, C., Henson, P., Anderson, J.R., Costelloe, R., Jarrett, A.J.M., Carson, C.J., MacFarlane, S.K., Gorton, J., Hutton, L., Troup, A, Williams, B., Khider, K., Bailey, A.H.E., Fomin, T. 2020. South Nicholson Basin seismic interpretation. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/132029L210 South Nicholson Deep Crustal Seismic Reflection Survey, NT and QLD, 2017. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/116881.

未来勘探计划（Exploring for the Future, EFTF）是澳大利亚政府发起、由澳大利亚地质调查局（Geoscience Australia）主导，与各州及北领地政府合作开展的项目。该计划第一阶段（2016-2020年）旨在通过提供全新的预竞争数据与相关信息，推动澳大利亚北部前沿地区的资源勘探行业投资，覆盖能源、矿产与地下水资源潜力领域（Carr等，2018）。

南尼科尔森盆地及周边紧邻区域位于古-中元古代的芒特艾萨省（Mount Isa Province）与麦克阿瑟盆地（McArthur Basin）之间。上述两个区域均已得到充分研究，但与之相邻的南尼科尔森区域研究程度较低，且多数岩体处于隐伏覆盖层之下，其盆地演化过程与资源潜力尚未得到充分认知。为填补这一研究空白，2017年针对南麦克阿瑟盆地南部至芒特艾萨西部岩系之间的区域开展了L210南尼科尔森深部地壳地震勘测，该测线横穿南尼科尔森盆地与墨菲省（Murphy Province），为上述区域搭建了关键的数据关联纽带（亦称L210南尼科尔森深部地壳反射地震勘测）。

本次勘测的核心目标是对区域内重力响应值偏低的区域开展调查，以判断其是否属于厚层盆地沉积序列——正如邻近具有勘探潜力的比塔卢次盆地（Beetaloo Sub-basin）的情况一致。通过对本次勘测数据的解释工作，研究人员发现了一个全新的盆地：卡拉拉次盆地（Carrara Sub-basin），该盆地与南尼科尔森盆地东南部区域的重力低异常区相吻合。

本数据集包含基于2019年Carr等对L210南尼科尔森地震勘测（L210）的解释层位导出的XYZ点集，这些点集同时对应双向走时（Two Way Time, TWT，单位为毫秒，对应PreSTM_17ga测线）与深度（以PreSDM_17GA测线的深度索引重新解释后的米制数值）。本数据集的坐标参考系统为WGS 1984澳大利亚遥感中心兰伯特坐标系。地震参考基准面为350米，各测线的SEGY文件的EBCDIC头文件中均记载了地震参考基准面的相关信息。

### 参考文献
1. Carr, L.K., Southby, C., Henson, P., Costello, R., Anderson, J.R., Jarrett, A.J.M., Carson, C.J., Gorton, J., Hutton, L.J., Troup, A., Williams, B., Khider, K., Bailey, A. & Fomin, T. 2019. 《未来勘探计划：南尼科尔森盆地地质概况与地震解释》，报告编号2019/21，澳大利亚地质调查局，堪培拉。http://dx.doi.org/10.11636/Record.2019.021
2. Carr, L.K., Southby, C., Henson, P., Anderson, J.R., Costelloe, R., Jarrett, A.J.M., Carson, C.J., MacFarlane, S.K., Gorton, J., Hutton, L., Troup, A, Williams, B., Khider, K., Bailey, A.H.E., Fomin, T. 2020. 《南尼科尔森盆地地震解释》，澳大利亚地质调查局，堪培拉。http://dx.doi.org/10.11636/132029
3. 《2017年北领地与昆士兰州L210南尼科尔森深部地壳反射地震勘测》，澳大利亚地质调查局，堪培拉。https://pid.geoscience.gov.au/dataset/ga/116881.