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 a multiyear follow up of a $500,000 airborne survey. 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 SU seismic/ground penetrating radar reflection processing software WinSism seismic refraction 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 20 Zonge porous pot IP receiver electrodes approximately 12 km of wire 8 Zonge power winder reels and 5 Zonge breast reels 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 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 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 clark@bigskygeo.com