Geoscience Australia Marine Survey GA0332 (SS05/2011): Natural hydrocarbon seepage survey of the offshore northern Perth Basin - Mineralogy of seabed sediments.

In September and October of 2011 Geoscience Australia surveyed part of the offshore northern Perth Basin in order to map potential sites of natural hydrocarbon seepage. The primary objectives of the survey were to map the spatial distribution of seepage sites and characterise the nature of the seepage at these sites (gas vs oil, macroseepage vs microseepage; palaeo vs modern day seepage) on the basis of: acoustic signatures in the water column, shallow subsurface and on the seabed; geochemical signatures in rock and sediment samples and the water column; and biological signatures on the seabed. Areas of potential natural hydrocarbon seepage that were surveyed included proven (drilled) oil and gas accumulations, a breached structure, undrilled hydrocarbon prospects, and areas with potential signatures of fluid seepage identified in seismic, satellite remote sensing and multibeam bathymetry data. Within each of these areas the survey acquired: water column measurements with the CTD; acoustic data with single- and multi-beam echosounders, sidescan sonar and sub-bottom profiler (sidescan not acquired in Area F as it was too deep in places); and sediment and biological samples with the Smith-McIntyre Grab. In addition, data were collected with a remotely operated vehicle (ROV), integrated hydrocarbon sensor array, and CO2 sensor in selected areas. Sampling with the gravity corer had limited success in many of the more shallow areas (A-E) due to the coarse sandy nature of the seabed sediments. This dataset comprises mineraology of the upper 2cm of seabed sediment. The mineral assemblage includes quartz, aragonite, calcite and high-Mg calcite expressed as mol %.

2011年9月至10月，澳大利亚地质调查局（Geoscience Australia）对珀斯盆地北部近海部分区域开展勘测，旨在绘制天然烃类渗漏的潜在点位分布图。
本次勘测的核心目标为：基于水体、浅表层地下及海底的声学特征，岩石、沉积物样品与水体中的地球化学特征，以及海底的生物特征，绘制渗漏点位的空间分布，并表征各点位的渗漏性质（天然气与原油、宏观渗漏与微观渗漏；古渗漏与现代渗漏）。
本次勘测覆盖的潜在天然烃类渗漏区域包括：经钻井验证的已探明油气藏、一处破损构造、未钻探的油气远景靶区，以及经地震、卫星遥感和多波束测深数据识别出具有流体渗漏潜在特征的区域。
在上述各区域内，本次勘测采集了以下数据与样品：利用CTD（温盐深仪）开展水体剖面测量；利用单波束与多波束回声测深仪、侧扫声呐及浅地层剖面仪采集声学数据（F区域因局部水深过深，未获取侧扫声呐数据）；利用Smith-McIntyre采泥器（Smith-McIntyre Grab）采集沉积物与生物样品。
此外，在选定区域内还利用遥控无人潜水器（ROV）、集成烃类传感器阵列及CO₂传感器完成了数据采集。重力岩心取样器（gravity corer）的取样在多数浅水区（A-E区）效果有限，原因是海底沉积物为粗砂质。
本数据集包含海底表层0至2厘米沉积物的矿物学数据，矿物组合以摩尔百分比（mol %）表示，涵盖石英、文石、方解石及高镁方解石。