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 fifteen 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, 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
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
NGA GM-SYS gravity and magnetic modeling software using prisms
UBC's GRAV3D and MAG3D 3D smooth model inversion software for gravity and magnetic data
Kansas Geological Survey MASW (surface wave) and seismic refraction processing software
SU seismic/ground penetrating radar reflection processing software
ArcView GIS software
Golden Software's Didger digitizing program
Numerous public domain, commercial, and personal programs written in FORTRAN, C, and BASIC for formatting and processing various geophysical data types.

I am gradually acquiring all of the field gear necessary to perform surveys. At the present time I own:

Trimble 5700 survey grade (centimeter level accuracy) GPS base/rover pair with RTK and post processing options
LaCoste and Romberg G model gravimeter with electrostatic readout
Iris Instruments Elrec Pro 10 channel time domain resistivity/IP receiver
Walcer KW10 10 kVA time domain transmitter
Walcer MG-12A 12 kW 400 Hz motor generator
BRGM (early Iris Instruments) VIP3000 3 kVA transmitter
Honda 5 kW 60 Hz motor generator
GEM GSM-19W Overhauser walking magnetometer/gradiometer
GEM GSM-19TG proton precession walking magnetometer/gradiometer
Scintrex proton precession base station magnetometer
Geometrics 24 channel SmartSeis seismograph with 4.5 Hz, 8 Hz, and 100 Hz geophones for MASW, refraction, and reflection surveys
Bison AWGIII 550 lb. accellerated weight drop mounted on trailer
MALA Easy Locator 450 MHz ground penetrating radar with rough terrain cart
Geofyzika GS-512 gamma ray spectrometer (modern with digital storage) with large (3") external crystal (with ability to store full spectrum and not just four windows)
Exploranium GR110 gamma ray scintillometer
Apex Parametrics Max-Min II+ EM induction system (222, 444, 888, 1777, 3555 Hz) with digital storage
Apex Parametrics Max-Min II EM induction system (222, 444, 888, 1777, 3555 Hz, analogue)
Geonics EM-16R VLF receiver (approximately 20 kHz range) with resistivity option

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. I also discuss some of the advantages and potential pitfalls of using GPS positioning systems with geophysical surveys.

Clark Jorgensen
P.O. Box 353
Bozeman, Montana 59771
+1 (406) 587-6330 telephone/facsimile
+1 (406) 580-9718 mobile