Corrected IODP Gamma Ray Attenuation (GRA) densities and calculated porosities derived from the LILY Database
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The dataset GRA_Densities_Corrected_and_Porosities_2023-12-26.csv is derived from an analysis of data from the LILY Database (https://doi.org/10.5281/zenodo.8408296) as described in Childress et al. (2024, https://doi.org/10.1029/2023GC011287). The file contains over 3.7 million corrected gamma ray attenuation (GRA) bulk density data derived from the LILY database file GRA_DataLITH.csv. It also contains over 3.7 million porosity estimates that are computed from the corrected GRA bulk density using grain densities computed for each lithology from Moisture and Density (MAD) grain densities (derived from LILY file MAD_DataLITH.csv). Citation: Please cite Childress et al. (2024) when using these data: Childress, L.B., Acton, G.D., Percuoco, V.P., Hastedt, M., 2024. The LILY Database: Linking Lithology to IODP Physical, Chemical, and Magnetic Properties Data, Geochemistry, Geophysics, Geosystems, 25, https://doi.org/10.1029/2023GC011287. GRA_Densities_Corrected_and_Porosities_2023-12-26.csv file size uncompressed is 950 Mb. Data File format: Exp: expedition number Site: site number Hole: hole number Core: core number Type: Type indicates the coring tool used to recover the core (typical types are F, H, R, X; see Table S3 in Childress et al., 2024, https://doi.org/10.1029/2023GC011287). Sect: section number Offset (cm): position of the observation, measured relative to the top of a section. Depth CSF-A (m): location of the observation expressed relative to the top of a hole. Bulk density (GRA): bulk GRA density measured on whole core sections in g/cm^3. Timestamp (UTC): date and time the observation was made. Instrument: abbreviation or mnemonic for the GRA sensing device used to make this observation (GRA1 or GRA2). Instrument group: abbreviation or mnemonic for the data collection device (logger) used to acquire this observation (WRMSL). Text ID: automatically generated unique database identifier for a sample, visible on printed labels. Prefix: Prefix of the lithology Principal: Principal lithology Suffix: Suffix of the lithology Full Lithology: full lithologic name = Prefix + Principal + Suffix Simplified Lithology: categorization of lithologies (see Supporting Information in Childress et al., 2024, https://doi.org/10.1029/2023GC011287) Lithology Type: Sedimentary, Igneous, or Metamorphic Degree of Consolidation: consolidation state of the lithology. Lithology Subtype: categorization of lithologies (see Supporting Information in Childress et al., 2024, https://doi.org/10.1029/2023GC011287). Expanded Core Type: the actual coring type used, because some coring types were incorrectly grouped in the "Type" column (see Childress et al., 2024 for an explanation) Latitude (DD): Latitude in decimal degrees Longitude (DD): Longitude in decimal degrees Water Depth (mbsl): water depth in meters below sea level Grain Density: grain density associated with the Principal lithology, computed from MAD data Mean MAD Bulk Density: mean MAD bulk density associated with the Principal lithology. Std MAD Bulk Density: standard deviation in the MAD bulk densities for each Principal lithology. Correction Basis: the GRA bulk densities are corrected based on coring tool used. If the RCB was used, then the lithology cored by the RCB is used in determining the size of the correction. Median Difference: The correction that will be applied based on the median difference between the raw GRA bulk density and the colocated MAD bulk density for a specific Correction Basis. GRA Bulk Density Corrected: The corrected GRA bulk density in g/cm^3. Porosity: porosity computed from the corrected GRA bulk densities and grain density. Deviation: difference between "GRA Bulk Density Corrected" and "Mean MAD Bulk Density", which is the deviation the corrected density has from that expected for its Principal lithology. N Deviations: The number of standard deviations by which the observation differs from the expected value (= Deviation/(Std MAD Bulk Density)), which is useful for identifying outliers. GitHub Repository: Contains a few notebooks to demonstrate how to work with the LILY database IODP LILY GitHub Repository
本数据集GRA_Densities_Corrected_and_Porosities_2023-12-26.csv源自对LILY数据库（LILY Database，https://doi.org/10.5281/zenodo.8408296）数据的分析，相关细节见Childress等人（2024，https://doi.org/10.1029/2023GC011287）的研究。该文件包含源自LILY数据库文件GRA_DataLITH.csv的超370万条校正后伽马射线衰减（GRA，gamma ray attenuation）体密度数据；同时还包含超370万条孔隙度估算值，这些孔隙度由校正后的GRA体密度计算得到，其中颗粒密度则依据每种岩性从含水率与密度（MAD，Moisture and Density）颗粒密度（源自LILY文件MAD_DataLITH.csv）中提取。 引用规范：使用本数据集时，请引用如下文献： Childress, L.B., Acton, G.D., Percuoco, V.P., Hastedt, M., 2024. 《LILY数据库：关联国际大洋发现计划（IODP，International Ocean Discovery Program）物理、化学及磁特性数据》，《地球化学、地球物理学、地球系统》，25卷，https://doi.org/10.1029/2023GC011287。 GRA_Densities_Corrected_and_Porosities_2023-12-26.csv未压缩大小为950 Mb。 数据文件字段说明： - Exp：航次编号 - Site：站位编号 - Hole：钻孔编号 - Core：岩心编号 - Type：取心类型，指示用于回收岩心的取心工具（常见类型包括F、H、R、X；详见Childress等人2024年文献中的表S3，https://doi.org/10.1029/2023GC011287） - Sect：岩心片段编号 - Offset (cm)：观测位置，以岩心片段顶部为基准的相对距离，单位为厘米 - Depth CSF-A (m)：以钻孔顶部为基准的CSF-A相对深度，单位为米 - Bulk density (GRA)：全岩心片段测得的GRA体密度，单位为g/cm³ - Timestamp (UTC)：观测完成的日期与时间（协调世界时） - Instrument：本次观测所用GRA传感设备的缩写或助记符（GRA1或GRA2） - Instrument group：采集本次观测数据的数据记录设备（记录仪）的缩写或助记符（WRMSL） - Text ID：自动生成的样本唯一数据库标识符，可在打印标签上查看 - Prefix：岩性前缀 - Principal：主要岩性 - Suffix：岩性后缀 - Full Lithology：完整岩性名称 = 前缀 + 主要岩性 + 后缀 - Simplified Lithology：岩性分类体系（详见Childress等人2024年文献的补充材料，https://doi.org/10.1029/2023GC011287） - Lithology Type：岩性类型，分为沉积岩、火成岩或变质岩 - Degree of Consolidation：岩性固结状态 - Lithology Subtype：岩性子分类（详见Childress等人2024年文献的补充材料，https://doi.org/10.1029/2023GC011287） - Expanded Core Type：实际取心类型，因部分取心类型在“Type”列中存在错误分组（详见Childress等人2024年文献的相关解释） - Latitude (DD)：十进制格式的纬度 - Longitude (DD)：十进制格式的经度 - Water Depth (mbsl)：水深，单位为米（海平面以下） - Grain Density：与主要岩性对应的颗粒密度，由MAD数据计算得到 - Mean MAD Bulk Density：与主要岩性对应的平均MAD体密度 - Std MAD Bulk Density：各主要岩性的MAD体密度标准差 - Correction Basis：GRA体密度的校正依据，基于所使用的取心工具。若使用反向套管取心（RCB），则以RCB取心所获取的岩性作为校正尺度的确定依据 - Median Difference：基于特定校正依据下，原始GRA体密度与同位置MAD体密度的中位数差值得到的校正量 - GRA Bulk Density Corrected：校正后的GRA体密度，单位为g/cm³ - Porosity：由校正后的GRA体密度与颗粒密度计算得到的孔隙度 - Deviation：“校正后GRA体密度”与“平均MAD体密度”的差值，即校正后密度相对于对应主要岩性预期密度的偏差值 - N Deviations：观测值与预期值的标准差倍数（= Deviation/(Std MAD Bulk Density)），可用于识别异常值 GitHub 仓库： 包含若干用于演示LILY数据库操作方法的Jupyter笔记本 IODP LILY GitHub 仓库
