2.16.3.3. pycsamt.geology.rock_library

Built-in rock/fluid resistivity table for pycsamt.geology.lithology.

This module holds only data: BUILTIN_ROCKS, a flat list of (name, rho_min, rho_max, color, description, code, source) tuples consumed by pycsamt.geology.lithology.RockDatabase.default(). It carries no classification logic, so it can grow – new rows, new subsections, a locally curated regional variant kept alongside it – without touching pycsamt.geology.lithology at all. Contributors extending the table for a specific commodity, climate, or region should add rows here, grouped under a labelled subsection with a literature citation in source, rather than editing the classification engine.

Resistivity ranges are ohm metres, linear scale, drawn from widely cited compilations rather than from any single fetchable dataset – no public, machine-readable API currently maps rock name directly to a resistivity range (see pycsamt.geology.rock_providers for how a project-specific or organisation-internal source can be plugged in instead). Primary references:

• Palacky, G.J. (1988), “Resistivity characteristics of geologic targets”, in Nabighian, M.N. (ed.), Electromagnetic Methods in Applied Geophysics, Vol. 1, Society of Exploration Geophysicists.

• Telford, W.M., Geldart, L.P., Sheriff, R.E. (1990), Applied Geophysics, 2nd ed., Cambridge University Press.

• Keller, G.V., Frischknecht, F.C. (1966), Electrical Methods in Geophysical Prospecting, Pergamon Press.

• Slichter, L.B., Telkes, M. (1942), “Electrical properties of rocks and minerals”, in Handbook of Physical Constants, Geological Society of America.

Ranges are reproduced as round, order-of-magnitude-faithful brackets consistent with these sources rather than as falsely precise per-sample values – individual field measurements routinely span the full width of a bracket and beyond, which is the same reason Lithology classification treats classification as a hypothesis rather than a measurement.