Big Sky Geophysics is a consulting and contracting company located in Bozeman, Montana. I operate the company as a sole proprietor. I have been working as a geophysicist for over twenty-five years and both execute field work and perform survey planning, processing, and interpretation. I have worked throughout North and Central America and in Africa on projects ranging is scope from one day engineering surveys to multiyear follow ups of airborne surveys. I use potential field (gravity and magnetics), electrical/EM, seismic and radiometric methods for applications in mineral exploration, hydrocarbon exploration, and engineering studies.
I believe in using the best equipment possible for collecting, processing, and interpreting geophysical data. I use a large variety of computer programs including:
Geosoft Oasis Montaj potential field mapping and processing software EMIT Maxwell EM processing and modeling software Fullagar Geophysics EmaxAIR time domain EM representation software Geotomo's resistivity/induced polarization modeling and smooth model inversion software based upon the code of Loke Allen Cogbill's gravity terrain correction software Encom Technology's ModelVision gravity and magnetic modeling software using prisms UBC's GRAV3D and MAG3D 3D smooth model inversion software for gravity and magnetic data Bill Petrick's (Industrial Imaging Technology) parallel processing finite difference 3D MT inversion software with MT formatting and processing software Kansas Geological Survey MASW (surface wave) and seismic refraction processing software Rayfract diving wave tomography and refraction processing software RadExPro reflection seismic processing software Golden Software's Didger digitizing program, Surfer mapping program, and Voxler 3D rendering program Mount Sopris WellCAD software for well log display Numerous public domain, commercial, and personal programs written in FORTRAN, C, and BASIC for formatting and processing various geophysical data types.
I currently perform at least some variation of virtually every type of surface geophysical survey and am rapidly expanding borehole surveying capabilities. At the present time I own:
- Potential Fields:
LaCoste and Romberg G model gravimeter with electrostatic readout
Geneq SXblue-SMART survey grade (centimeter level accuracy) GPS with RTK and post processing options (GPS, GLONASS, Galileo, and BeiDou)
GEM GSM-19W Overhauser walking magnetometer/gradiometer
GEM GSM-19TG proton precession walking magnetometer/gradiometer
Electrical/Electromagnetic:
Time Domain resistivity/induced polarization (IP)
EMIT SMARTem24 multifunction receiver (8 channel, 24 bit A/D)
Walcer KW10 10 kVA time domain transmitter
Iris Instruments VIP3000 3 kVA transmitter
Time Domain Electromagnetics (EM)
EMIT SMARTem24 multifunction receiver (8 channel, 24 bit A/D) with transmitter controller and fluxgate (B field) sensor
Crone Geophysics 30A transmitter system and Crone receiver coil (dB/dt field)
Geonics EM61 near surface conductivity system
Frequency Domain EM
AMT receivers (24 bit A/D, John Stodt amplifiers)- Geometrics G20K induction coils
- Apex Parametrics Max-Min II EM induction system (222, 444, 888, 1777, 3555 Hz)
- Geonics EM31 near surface conductivity system
Geonics VLF receiver (approximately 20 kHz range) with resistivity option
Mala Geoscience Easy Locator 450 MHz ground penetrating radar
Seismic:
Geometrics 120 channel seismic system (5 24 channel Geodes, 24 bit A/D)
4.5 Hz and 100 Hz geophones for MASW, refraction and reflection surveys
PEG-40 88 lb. accelerated weight drop mounted on a RZR Trail side-by-side
Bison AWGIII 550 lb. accelerated weight drop mounted on trailer
Radiometric:
Geofyzika GS-512 gamma ray spectrometer (modern with digital storage) with large (3") external crystal
Exploranium GR110 gamma ray scintillometer
Borehole:
Mount Sopris semi-portable 450 meter four conductor winch and 1000 meter one conductor winch
Mount Sopris Scout (for digital tools) and MX (for analogue tools) data loggers
EMIT DigiAtlantis 3-component fluxgate (B field) receiver for magnetic, TDEM, and borehole deviation surveys
Geonics BH43-3 three component coil (dB/dt field) receiver for TDEM surveys
Mount Sopris QL40-ABI-2G acoustic televiewer for borehole imaging, structural interpretation, and borehole deviation
Mount Sopris QL40-IP resistivity/IP tool for resistivity and induced polarization measurements
Mount Sopris 2PGA gamma ray probe for radiometric surveys
Stainless steel electrode for downhole current source IP surveys using winch
Array of four stainless steel electrodes for three dipole downhole receivers for IP surveys using four conductor winch - Geometrics G20K induction coils
If you feel I may be able to help you with a project, please contact me. I enjoy both field work and processing/interpretations and will work to incorporate any geophysical planning and results with additional data such as geologic mapping and well logs, geochemical sampling, and existing water table information. If you wish to have additional information about my experience and education, I have provided my resume. I am pretty fluent in Russian and German and speak some Spanish. I encourage you to consult the case studies.
Clark Jorgensen P.O. Box 353 Bozeman, Montana 59771 USA +1 (406) 587-6330 office +1 (406) 580-9718 mobile clark@bigskygeo.com
