Salt Diapirism: Importance of Temperature, and Energy Source of Emplacement

摘要: Heat is critical for the occurrence of salt intrusion. Increased temperature greatly reduces ultimate strength and eliminates work hardening. When heated above 400°F (205°C), it becomes soft plastic flows indefinitely with a pressure gradient about 33-100 kg/cm2 (460-1,400 psi). It during entire process intrusion, even extrusion at surface. Thus, time extrusion, can flow by simple gravity, like "glacier," as long remains hot. buried depth more than 25,000 ft, sedimentary mobile because high behaves hydrodynamically; moves laterally to places lower overburden pressure, where doming or piercement occurs. Once initiated, will continue until supply depleted cut off, either coming together overlying underlying strata additional supplies have not been necessary maintain plasticity. The energy impelling lateral radial place be attributed only an imbalance in geostatic load overburden, but after occurs, differential ever-increasing effect buoyancy cause rise rapidly th ough strata. Buoyancy effective force when height intrusion has increased greatly. requirement modifying effect. emplacement igneous masses such volcanic plugs, granite batholiths, diamond pipes, carbonatites, serpentine bodies (Gussow, 1962), intrusive mud volcanoes, shale diapirs, ice piercements pingos 1954), frost boils similar that piercements. In all cases prime motivating weight 1962). writer postulates salt-dome thermally activated rate rather rapid--probably catastrophic on geologic scale. movement which interpreted growth actually measure compaction adjacent sediments. fundamental mechanics outlined diapirism are applicable generally, other forms diapirism.