Electromagnetic study in the Minas-Bahia Graphite Province (MBGP)

Description

The Inter-American Development Bank (IDB), in close coordination with the Geological Survey of Brazil (SGB), is seeking a specialized engineering or geophysics consulting firm to execute a helicopter-borne airborne Time-Domain Electromagnetic (TDEM) survey. The primary focus of the assignment is to map subsurface electrical conductivity distributions to enhance the regional geological understanding and support the identification of graphite mineralized zones.

1. Project objectives and survey parameters
Subsurface mapping: Delineating the distribution of electrical conductivity across the southeastern portion of the Minas-Bahia Graphite Province (MBGP).

Mineral characterization: Enhancing geological models to isolate, characterize, and evaluate prospective graphite-bearing structures.

Survey volume: Operational execution of exactly 334.50 linear kilometers of flight lines, adhering strictly to the boundary coordinates and flight line geometries defined by the SGB.

2. Operational standards and safety compliance
Methodological alignment: All planning, acquisition, and processing workflows must strictly comply with the technical manuals, operational spreadsheets, and procedural guidelines provided by the SGB.

Supervisory framework: Field operations will be conducted under the direct supervision of the IDB and in continuous alignment with the SGB technical team.

Rigid target parameters: Maintaining strict flight line spacing, pre-planned sampling intervals, and specific sensor heights while fully observing local safety standards and field access constraints.

3. Key activities and technical phases
The contract lifecycle is structured across four sequential operational streams:

Inception and planning: Reviewing baseline cartographic and geological inputs to deliver a comprehensive Inception Report. This document must detail the field methodology, mobilization strategy, work schedule, organizational chart, logistical planning, and dedicated health and safety protocols.

Field data acquisition: Mobilizing the specialized aircraft and TDEM system to the survey area to collect high-resolution electromagnetic data along the approved flight tracks, keeping strict control over system noise levels and data gaps.

Data processing and quality control: Treating raw electromagnetic datasets through advanced geophysical routines, including stacking, filtering, removal of atmospheric contributions, transmitter waveform correction, drift correction, channel leveling, and the calculation of decay constants and apparent conductivity.

Reporting and handover: Compiling gridded and profile mapping products, populating a validated georeferenced database, delivering a final technical presentation to both the SGB and the IDB, and finalizing the project close-out.

Note: Interested companies must review the requirements in the BEO Bidders Portal.