Definition of a Plume. Stress- and dike-based models recognize that the difference between a surface volcano (âhotspotâ) and sills, intrusion, magma chambers and underplating is simply one of the orientation of the stress field, not the absolute temperature of the mantle, or even the magnitude of the stress.
Hempstead is a city in Waller County, Texas, United States, part of the HoustonâThe WoodlandsâSugar Land metropolitan area. It is the county seat of Waller County.
After the annexation of Texas to the United States in 1845, portions of Gonzales County were detached to form what are now the counties of Caldwell, Comal, DeWitt, Fayette, Guadalupe, Jackson, Lavaca, and Victoria.