The drillings of the ICDP-DIVE project located in the Central part of the Ivrea-Verbano Zone at the Linea Cadorna in Migiandone near Ornavasso were accompanied by On-Line Gas Monitoring. During the drilling of both boreholes 5071_1_A (IGSN ICDP5071EH10001) and 5071_1_B (IGSN ICDP5071EH30001) O2, N2, 40Ar, 38Ar, 36Ar, CO2, CH4, H2, He and 222Rn were measured. The dataset contain for each species its concentration over time and depth. Gases were continuously recovered by degassing the drilling mud and quantified using two quadrupole mass spectrometers (QMS): an Omnistar GSD 300 (Pfeiffer Vacuum®, Germany) and a miniRUEDI (Gasometrix®, Switzerland) and an AlphaGUARD radon monitor (Bertin Technologies®, France). Baselines were corrected using the asymmetric least squares smoothing method from Eilers and Boelens (2005) resulting in an uncertainty not exceeding 3% for all the concentrations. All data provided are lag-time (and lag-depth) corrected with an error of less than 1 m.
For the determination of the exact location and drilling geometry of the ICDP expedition 5071 DIVE (Drilling the Ivrea-Verbano zonE) phase 1 boreholes, we have carried out a series of active seismic experiments to image the subsurface at high resolution (Greenwood et al., 2024). The two drilling sites of DIVE phase 1 are located in the Ossola valley (Figure 1) in the Central part of the Ivrea-Verbano zone, one in Megolo di Mezzo (5071_1_A: IGSN ICDP5071EH10001, Münthener, 2024a) and the other near Ornavasso (5071_1_B: IGSN ICDP5071EH30001, Münthener, 2024a). A total of 4 seismic reflection surveys, one in Megolo, two in Ornavasso (Ornavasso primary and Or-navasso secondary), and a transect crossing from Premosello-Chiovenda south towards Megolo, make up the MicrO-SEIZE (MOS) data base.
The MOS surveys were conducted over a period of 12 days mid to late June 2019, utilizing a 26,000 lb (12,247 kg) EnviroVibe2™ vibrator source. Survey planning utilised existing roads, pathways, and open grass fields to cover as much area as possible around the borehole sites, to reduce the envi-ronmental impact on cultivation, and to ease operation logistics. A full description of the data can be found in Greenwood et al. (2024) and the data description file accessible via the data download link.
To structurally and petrophysically characterize the rock mass in the Ivrea-Vebarno Zone, a comprehensive downhole geophysical dataset from has been collected in borehole 5071_1_B (IGSN ICDP5071EH30001) of the ICDP-DIVE project located in the Central part of the Ivrea-Verbano Zone at the Linea Cadorna in Migiandone near Ornavasso. Natural gamma ray (GR), magnetic susceptibility (MS), mud parameter (MP), dual laterolog resistivity (DLL), full waveform sonic (FWS), acoustic televiewer (ATV), optical televiewer (OTV), single point resistance (SPR) logs and vertical seismic profiling data (VSP) are recorded.
The borehole data is complemented by magnetic susceptibility measurements conducted on the cored rocks on site during the drilling campaign and by density measurements of 96 core sections using a multi sensor core logger (MSCL) after the drilling campaign at the BGR Core Repository in Berlin-Spandau. Additionally, for 15 whole-round core samples, the bulk density as well as ultrasonic velocities are measured at ambient conditions in the laboratory at Montanuniversität Leoben.
Several logging campaigns have been conducted. The logging data contain logs from a logging campaign conducted by GFZ-Operational Support Group (OSG) after the drilling operation in December 2022 and from complementary logging operations carried out by Montanuniversität Leoben and the University of Lausanne in June 2023. The repository data include: processed and/or interpreted properties of the well log data; zero-offset VSP P- and S-wave velocities; and petrophysical properties inferred from the core measurements. The full description of the data and methods is provided in the data description file.
This data set was collected in the frame of the ICDP drilling project DIVE (Drilling the Ivrea-Verbano ZonE) to determine the thermal properties of lower crustal lithologies and their variabilities. Two boreholes were drilled, the first 5071_1_B (in Ornavasso, final depth: 578.5 m) intersects the amphibolite-facies metasedimentary succession of the Ivrea-Verbano Zone, and the second borehole 5071_1_A (in Megolo, final depth: 909.5 m) is located within the mafic complex.
Thermal properties were measured on fresh drill cores from the two DIVE boreholes and surface samples collected from nearby outcrops. The data set comprises thermal conductivity (TC), thermal diffusivity (TD), and specific heat capacity (Cp) measurements as well as measurements on concentrations of heat producing elements (HPE) Uranium (U), Thorium (Th), and Potassium (K) and the calculated radiogenic heat production (A).