µCT data of two drill cores of fractured crystalline rock (Grimsel)

Two crystalline rock drill cores from the Grimsel site were scanned with a Nikon XT H 225 - scanner. The samples were prepared (formatted and cast in epoxy) by UJV Rez, Czech Republic. The CT-data were acquired and processed at HZDR-FWOT. Sample 1 (GAM_UJV_1C_1) contains a complex system of interconnected fractures.<br> Sample 2 (GAM_UJV_1C_2) contains one single end-to-end fracture with larger aperture. Size of both samples: Diameter 80 mm, length 165 mm. Two tomograms were acquired for both samples:<br> 1) Complete drill core as one scan, voxel size ca. 75 µm.<br> 2) HR-tomogram merged from three sections with maximum resolution, voxel size ca. 40 µm. The tomograms were stored as 3D-raw files. Data format, acquisition parameters, and processing workflow, are documented in the tomogram header files (nrrd-format (text): see https://teem.sourceforge.net/nrrd/format.html).<br> This data format is importable into open-source visualization programs as 3D slicer (https://www.slicer.org) or Paraview (https://www.paraview.org). The data processing has been conducted with Avizo (https://www.thermofisher.com/de/de/home/electron-microscopy/products/software-em-3d-vis/avizo-software.html). Files:<br> Sample 1<br> GAM_UJV_1C_1_complet-2_01_NLM: Graylevel image of complete sample, ring artifact removal, non-local-means filter<br> GAM_UJV_1C_1_complet-2_01_thresholded: Tentative label image of complete sample, threshold segmentation with manual edit<br> Merged-GAM_UJV_1C_1_HR.Frac_section: Graylevel image of merged fracture section, unfiltered<br> Merged-GAM_UJV_1C_1_HR.Frac_section.Threshold: Tentative label image of merged fracture section, adaptive threshold segmentation with manual edit<br> GAM_UJV_1C_1_complet_2.png: Figure of complete sample <br> GAM_UJV_1C_1_HR_Frac_Y2.png: Figure of merged high-resolution tomogram Sample 2<br> GAM_UJV_1C_2_complet_01.filtered: Graylevel image of complete sample, ring artifact removal, non-local-means filter<br> GAM_UJV_1C_2_complet_01.filtered.thresholded: Tentative label image of complete sample, threshold segmentation with manual edit<br> Merged-GAM_UJV_1C_2_A_01.Frac_section.filtered: Graylevel image of merged fracture section, ring artifact removal, non-local-means filter<br> Merged-GAM_UJV_1C_2_A_01.Frac_section.filtered.segm: Tentative label image of merged fracture section, threshold segmentation with manual edit<br> GAM_UJV_1C_2_complett_2.png: Figure of complete sample<br> GAM_UJV_1C_2_HR_Frac_Y2.png: Figure of merged high-resolution tomogram Original acquistion data are stored on the HZDR bulk data storage system and available for reprocessing on request. <br> Financial support was granted from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 847593 (EURAD, WP FUTURE, task 2.2).<br>

本次研究使用尼康XT H 225型扫描仪（Nikon XT H 225）对采集自格里姆塞尔（Grimsel）点位的两块结晶岩岩心进行了扫描。样品制备（表面打磨与环氧树脂包埋）由捷克共和国雷兹的UJV研究院完成。CT数据的采集与处理由HZDR-FWOT完成。样品1（GAM_UJV_1C_1）内部存在一套复杂的相互连通裂隙系统。
样品2（GAM_UJV_1C_2）则包含一条单条贯穿式裂隙，且裂隙开度更大。两块样品的尺寸均为：直径80 mm，长度165 mm。
两块样品均采集了两套断层扫描图像：
1）完整岩心单次扫描图像，体素尺寸约75 µm；
2）由三个断面拼接而成的高分辨率（HR）断层扫描图像，体素尺寸约40 µm。
所有断层扫描图像均以3D原始文件格式存储。数据格式、采集参数与处理流程均记录于断层扫描图像的头文件中（文本型NRRD格式，详见https://teem.sourceforge.net/nrrd/format.html）。
该数据格式可导入至开源可视化软件，如3D Slicer（https://www.slicer.org）与ParaView（https://www.paraview.org）中。本次数据处理使用Avizo软件完成（https://www.thermofisher.com/de/de/home/electron-microscopy/products/software-em-3d-vis/avizo-software.html）。
文件详情如下：
样品1
GAM_UJV_1C_1_complet-2_01_NLM：完整样品的灰度图像，已完成环形伪影去除与非局部均值滤波处理
GAM_UJV_1C_1_complet-2_01_thresholded：完整样品的初步标记图像，经阈值分割并辅以人工编辑
Merged-GAM_UJV_1C_1_HR.Frac_section：合并裂隙断面的灰度图像，未经过滤波处理
Merged-GAM_UJV_1C_1_HR.Frac_section.Threshold：合并裂隙断面的初步标记图像，经自适应阈值分割并辅以人工编辑
GAM_UJV_1C_1_complet_2.png：完整样品可视化图
GAM_UJV_1C_1_HR_Frac_Y2.png：高分辨率拼接断层扫描图像可视化图
样品2
GAM_UJV_1C_2_complet_01.filtered：完整样品的灰度图像，已完成环形伪影去除与非局部均值滤波处理
GAM_UJV_1C_2_complet_01.filtered.thresholded：完整样品的初步标记图像，经阈值分割并辅以人工编辑
Merged-GAM_UJV_1C_2_A_01.Frac_section.filtered：合并裂隙断面的灰度图像，已完成环形伪影去除与非局部均值滤波处理
Merged-GAM_UJV_1C_2_A_01.Frac_section.filtered.segm：合并裂隙断面的初步标记图像，经阈值分割并辅以人工编辑
GAM_UJV_1C_2_complett_2.png：完整样品可视化图
GAM_UJV_1C_2_HR_Frac_Y2.png：高分辨率拼接断层扫描图像可视化图
原始采集数据存储于HZDR大容量数据存储系统中，可应要求提供用于重新处理。
本研究获欧盟地平线2020研究与创新计划资助，资助协议编号为847593（项目：EURAD，工作包FUTURE，任务2.2）。