Geochemistry of oil stains from NDI Carrara 1 and NDI BK10, Northern Territory, Australia

Exploring for the Future (EFTF) is an Australian Government program led by Geoscience Australia, in partnership with state and Northern Territory governments, and aimed at stimulating exploration now to ensure a sustainable, long-term future for Australia through an improved understanding of the nation’s minerals, energy and groundwater resource potential. The EFTF program is currently focused on eight interrelated projects, united in growing our understanding of subsurface geology. One of these projects, the Barkly–Isa–Georgetown project, will deliver new data and knowledge to assess the mineral and energy potential in undercover regions between Tennant Creek, Mount Isa and Georgetown. Building on the work completed in the first four years of the Exploring for the Future program (2016-2020), the project undertook stratigraphic drilling in the East Tennant and South Nicholson regions, in collaboration with MinEx CRC and the Northern Territory Geological Survey (NTGS). This work tests geological interpretations and the inferred mineral and energy potential of these covered regions. Geoscience Australia is undertaking a range of analyses on physical samples from these drill holes including geochemistry and geochronology. The South Nicholson National Drilling Initiative (NDI) Carrara 1 drill hole is the first drillhole to intersect the Proterozoic rocks of the Carrara Sub-Basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys acquired as part of the EFTF. It is located on the western flanks of the Carrara Sub-basin on the South Nicholson Seismic line 17GA-SN1, reaching a total depth of 1751 m, intersecting ca. 630 m of Cambrian Georgina Basin overlying ca. 1100 m of Proterozoic carbonates, black shales and minor siliciclastics.The NDI BK10 drill hole is the tenth drill hole drilled as part of the East Tennant project aimed to constrain the East Tennant basement geology and calibrate predictive mineral potential maps to further our understanding of the prospectivity of this region. NDI BK10 reached a depth of 766 m and intersected basement at 734 m. Overlying these basement metasediments of the Alroy Formation, the drillhole intersected about 440 m of Proterozoic rocks underlain by ca. 300 m rocks of Cambrian age from the Georgina Basin.During coring of NDI Carrara 1 and NDI BK10, cores containing oil stains were identified and sent for geochemical analysis to Geoscience Australia. This report presents the geochemical data from these oil stains including biomarker and isotopic data.

未来勘探计划（Exploring for the Future, EFTF）是澳大利亚政府发起的项目，由澳大利亚地质调查局（Geoscience Australia）牵头，与各州及北领地政府合作开展，旨在推动当前的勘探工作，通过深化对澳大利亚矿产、能源与地下水资源潜力的认知，保障该国资源的可持续长期发展。
该计划目前聚焦于8个相互关联的项目，核心目标均为深化对地下地质情况的认知。其中，巴克利-艾萨-乔治敦项目（Barkly–Isa–Georgetown）将提供全新数据与认知，以评估滕南特克里克、芒特艾萨与乔治敦之间覆盖区的矿产与能源潜力。
依托未来勘探计划2016-2020年前四年的工作成果，该项目与矿物勘探合作研究中心（MinEx CRC）、北领地地质调查局（Northern Territory Geological Survey, NTGS）合作，在东滕南特与南尼科尔森地区开展了地层钻探。此项工作旨在验证相关地质解译，以及上述覆盖区推断出的矿产与能源潜力。澳大利亚地质调查局（Geoscience Australia）正对这些钻孔获取的实物样品开展一系列分析，包括地球化学与地质年代学分析。
南尼科尔森国家钻探倡议（National Drilling Initiative, NDI）Carrara 1钻孔是首个钻穿卡拉拉次盆地元古代岩层的钻孔，卡拉拉次盆地是依托未来勘探计划中的地震勘探解译成果，在南尼科尔森地区新发现的沉积中心。该钻孔位于南尼科尔森地震测线17GA-SN1上的卡拉拉次盆地西翼，总钻探深度达1751米，钻穿约630米的寒武纪乔治娜盆地岩层，其下伏约1100米的元古代碳酸盐岩、黑色页岩及少量硅质碎屑岩。
国家钻探倡议BK10钻孔是东滕南特项目的第十个钻孔，旨在明确东滕南特基底地质情况，并校准预测性矿产潜力地图，以进一步深化对该区域找矿潜力的认知。该钻孔钻探深度达766米，在734米处钻遇基底岩层。在阿尔罗伊组的基底变沉积岩之上，该钻孔钻穿约440米的元古代岩层，其下伏约300米的寒武纪乔治娜盆地岩层。
在对NDI Carrara 1与NDI BK10钻孔取芯过程中，科研人员发现了含有油迹的岩芯，并将其送至澳大利亚地质调查局（Geoscience Australia）开展地球化学分析。本报告呈现了这些油迹的地球化学数据，包括生物标志物与同位素数据。