The geology of Tarrant County is made up of four basic types of rock including limestone (many types based on age of deposition and surrounding environment), shale, sandstone and clay. They all arrived in Texas via sedimentary processes occurring over millions of years. Because of their arrival here through these processes, the layers of rocks occur in wide and narrow fingers across the landscape. The layered, weathering of these rock types are responsible for the four unique ecoregions found in the county: Blackland Prairie, the East and West Cross Timbers, and the Fort Worth Prairie, a local variant of the Grand Prairie.
Geology of an area is described by the bedrock and topography. It is an important factor that influences what plant species can grow and develop in an area. Bedrocks vary in different hardness (which impacts erosion or rate of soil formation), acidity, and mineral compositions. As rocks erode, they create soil that combines with decomposing plant and animal matter to provide a substrate capable of supporting life. The texture of the bedrock is also an important part of creating the environment, making soil that drains easily or soils that retain moisture. These variations in mineral composition, texture, and acidity are the factors that influence plant communities. Thus, geology is the foundation that informs the development of all plant communities (assemblages of plants that occur together within these restrictions). It is important to note that soil formation occurs over millions of years.
The foundation of all plant life (and really, all life) is built on soil formed over millions of years. Made of decomposed rock, plant and animal matter, soil contains many micro and macro nutrients (nitrogen, phosphorous, potassium, magnesium, to name a few) necessary for plants to grow and develop. Combined with carbon dioxide from the air, these nutrients form the chemical basis of all of the compounds that a plant needs to live. Created by the erosion and weathering of rock, soil strongly informs the type of plants that grow in it. In some cases, the geology may be so extreme or unusual as to cause high endemism (unique only to that region or place). An example of this is serpentine, a type of igneous rock that was laid down billions of years ago in small belts extending from Newfoundland to Texas. This affects the shape, available minerals and chemistry of the soil, which in turn affects the plants growing in it. Serpentine areas have higher pH (more alkaline), silica, iron, magnesium and more. The serpentine soils of the Llano Uplift in central Texas help to form an oak, juniper, mesquite savanna with fairly sparse vegetation and limited tree density. At least seven plants are thought to be endemic to the Llano Uplift. They include a sandmint, bellflower, quillwort, spiderwort and corn salad.
Geology of an area is described by the bedrock and topography. It is an important factor that influences what plant species can grow and develop in an area. There is a wide variety of bedrocks, and all may vary in different hardness (which impacts erosion or rate of soil formation), acidity, and mineral compositions. As rocks erode, they create soil that combines with decomposing plant and animal matter to provide a substrate capable of supporting life. The texture of the bedrock is also an important part of creating the environment, making soil that drains easily or soils that retain moisture. These variations in mineral composition, texture, and acidity are the factors that influence plant communities. Thus, geology is the foundation of all plant communities (assemblages of plants that occur together within these restrictions).
The foundation of all plant life is built on soil. Made of decomposed rock, plant and animal matter, soil contains many micro and macro nutrients (nitrogen, phosphorous, potassium, magnesium, to name a few) necessary for plant growth and development. Combined with carbon dioxide from the air, these nutrients form the chemical basis of all of the compounds that a plant needs to live (and also necessary for our survival). Created by the erosion and weathering of rock, soil strongly informs the type of plants that grow in it. In some cases, the geology may be so extreme as to cause high endemism (unique only to that region or place).