Investigating Geometrical Granite Landscapes: A Comparative Framework, with Case Studies from California and Montana

Granite terrain occasionally produces landforms that look built: planar faces, right-angle intersections, coursed or stacked blocks, stepped terraces, standing monoliths. Some of these forms, including planar faces and stepped profiles, are well explained by ordinary joint-controlled weathering; right-angle intersections are a weaker signal on their own, since orthogonal jointing occurs naturally in granite but the same geometry is also a hallmark of dressed masonry, which is why this paper treats no single feature as diagnostic of origin (Section 9). In a smaller number of cases, this kind of morphology occurs at sites with independent evidence of human modification. This paper proposes a general framework for telling these cases apart, and applies it to new case-study material from Three Rivers and Kirch Flat, California, and from previously documented localities in Montana. We define granite’s relevant physical and mineralogical properties, state an explicit and deliberately narrow hypothesis expressed as testable, discriminating predictions, introduce an eight-category morphological typology (Types A-H) together with operational classification thresholds, and apply that typology across the California and Montana material and a wider set of comparanda: accepted anthropogenic granite construction (Sardinia, Great Zimbabwe, Osirion at Abydos, Mahabalipuram) and natural granite controls (Yosemite, Joshua Tree, City of Rocks, Dartmoor, Matobo Hills, Huangshan). We do not decide, for California or Montana, whether the documented features are natural or built; that question is left open and is the object of the phased research protocol proposed in Section 10. On the strength of the morphology alone, both localities belong in a coordinated program of future research, whatever that research eventually concludes about their origin.