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The Geological Bounties of Texas

The Role of Salt and Coal in Shaping Landscape and Life in East Texas


Cradled underneath the bedrock of East Texas lies a geological phenomenon that has served and continues to serve a pivotal role in the region's history and ecosystem dynamics: salt. These natural formations--found in the forms of both naturally occurring salt deposits and springs--have not only served as vital resources for humans but have also sustained various forms of wildlife for millennia. Originally formed as bedded evaporite deposits in the Gulf of Mexico during the Jurassic Period of the Mesozoic era, the growth of salt domes influenced the topography of Texas along the Gulf itself. [1]

Salt's Impact on Human Development

Through its geological ubiquity, salt has remained a mainstay in human development and the reinforcements of the habits of wildlife. Salt's value has been under underappreciated in the modern age, but throughout human history, entire empires have been built around the locational nexus of salt. Moreover, salt has defined the evolutionary and societal pathway for humanity; animals traveled to salt licks, hunters followed in their wake, and over time, the trails made way for roads and, eventually, human settlements. [2] The dietary need for sodium in herbivorous animals necessitated their habitual paths towards naturally occurring salt deposits, which made trails and settlements located close to these areas crucial for human survival in the region.

Indigenous Utilization of Salt

The indigenous inhabitants residing west of the Mississippi River have utilized salt as both an essential element of survival as well as a commodity for trade for over 1200 years; indigenous Tunica traders had been observed by Spanish colonists sifting, refining, and packaging salt for trade between tribes for goods such as skins and blankets in the mid-sixteenth century. [3] For the Caddo Native Americans that resided in the geographical area that is now East Texas, salt was not simply an important facet of trade, but a manifestation of political power that came to further prominence with the arrival of European settlers from the 15th century onwards. Cooperation between Native Americans and European settlers and their descendants was critical in the unearthing of many of the occurring salt deposits throughout East Texas; as information pertaining to the location of salt resources and their potential for productivity was expanded upon, by the mid-18th century, these areas served as both legitimization and incentivization for the colonization of the region. [4]

Salt Domes of Texas: Genesis of the Petroleum Industry

Salt domes formed in East Texas are primarily localized near the Gulf Coast. This area of concentration, known as the East Texas Basin, spans from Panola county and passes through Nacogdoches, Angelina, Polk, Liberty, and Chambers counties. [5] While the advent of the modern era has made salt comparatively less economically valuable, these salt domes still represent a momentous turn in both Texas and world history. The discovery of the mammoth salt dome located in Grand Saline in 1850 introduced widespread commercial salt making to the United States, and since 1931, has been the source of the salt supply of the Morton Salt Company. [6] Perhaps most momentous was the 1901 discovery of oil on Spindletop Hill, located near Beaumont; though oil was believed to be present in the area since 1865, the tremendous oil reservoirs unearthed in 1901 introduced one of the first oil booms in the United States. The year following the discovery of oil on Spindletop Hill witnessed the birth of the modern petroleum industry, directly resulting in the founding of the modern-day oil titans of Texaco, Exxon, and Mobil. [7]

Coal: More Than the Precursor to Oil

Despite salt's eminence and its lasting impact on the topography and societal beginnings of East Texas, the mineral wealth of the state is not merely confined to salt, but rich deposits of coal as well. The genesis of the modern petroleum industry spurred on by the discovery of oil beneath salt domes and salt deposits revolutionized Texas society, but it did not immediately replace the utility of coal. Oil's wide scale introduction into society was revolutionary, but coal was the essential domestic and industrial fuel of the 19th and 20th centuries and heavily mined and exported; it was not until the mid-20th century that oil would supplant coal as the dominant energy source of the modern era. [8]

Coal's Presence in East Texas

Coal, as one of the most ubiquitous geological elements in Texas, has long filled an important societal niche as both a commodity and a source of employment. East Texas serves as a veritable hotbed of coal deposits, and in the first geological survey of Texas in 1845, it was found that a profusion of bituminous coal and anthracite--the two most prized forms of coal--were found in rich deposits stretching from the Rio Grande to the Trinity River. [9] Referred to by geologists as a chief part of the Texas Claypan, the Trinity River Basin exists as part of the largest lignite coal band in North America, where the lignite is still used to powe local electrical plants. [10] The area of the Trinity River Basin shows more than just the patterns of economic mining efforts, as the present excavation of coal mirrors the historical import of the resource in the area. The Bedias Creek of East Texas was specifically mentioned in 1840s surveys of lignite deposits in the area, highlighting the importance of rivers and water channel confluences as nexuses for resource gathering; the presence of coal was well-known to the Native American tribes that inhabited Texas, as coal was used for both a fuel source and for domestic purposes. [11]


Rock Salt Sample from the Hockley Dome Mine, Hockley, Harris County, Texas
Rock Salt Sample from the Hockley Dome Mine, Hockley, Harris County, Texas A pure specimen of halite excavated from the Hockley salt dome in Harris County, Texas. Halite is the natural mineral form of both table and rock salt (NaCl), and the purity of the specimen results correlates directly to the surrounding minerals. This semi-opaque specimen is free of shifts in hue or coloration, marking it as a sample found in a pure salt dome. Source: Creator: Hockey Dome Mine
Gulf Coast Salt Dome
Gulf Coast Salt Dome Cutaway picture of a salt dome showing the stratified geological makeup of the dome and its surrounding geologic components resulting from diapirism. It is important to note the pockets of petroleum that occur around the salt dome, a naturally occurring phenomenon that would come to shape Texas in the modern era. Source:
Caddo Village Scene
Caddo Village Scene An envisioning of a Caddo village in East Texas, ca. 1100 CE. Living in sprawling, organized communities, the Caddo Native Americans were an agriculturally-centered society renowned for their prowess as basket weavers, farmers, and makers of pottery. Moreover, their proximity to natural salt deposits made them experts in salt making and refining, and with the advent of European settlers and explorers in North America, the Caddo rose to prominence as guides to salt deposits and as traders of the mineral resource. Source: Creator: George S. Nelson
Underground Picture of East Texas Salt Dome.
Underground Picture of East Texas Salt Dome. A photograph showcasing the vaulted arches of a salt dome taken underground in the 1940s by the United States Geological Survey (USGS). The salt dome exists at a depth of nearly 2000 feet below the surface, and despite the temperatures reaching ~90ºF, the nearly nonexistent levels of humidity create an environment perfectly suited for natural salt preservation. Source: Creator: United States Geological Survey Date: ca. 1940s
Industrial Mineral Map of Texas, 2008
Industrial Mineral Map of Texas, 2008 This map of the geological resources used in industrialism in Texas highlights the multitude of minerals situated in East Texas. The Texas Claypan has earned its name with the suffusion of clay throughout the region, but most importantly, the presence of salt along the eastern Gulf of Mexico details the enduring existence of salt in the area. Source: Creator: J. Richard Kyle, Bureau of Economic Geology
Lignite Coal
Lignite Coal A sample of lignite coal. Typically referred to as "brown coal," lignite coal is formed as a result of naturally compressed peat. Due to its moisture, its low carbon content makes it less sought after than anthracite or bituminous coal, but it has still historically been used in the generation of electricity. Source: Creator: United States Geological Survey Date: ca. 2013
Coal Pit at the Liberty Mine
Coal Pit at the Liberty Mine A modern coal mine in East Texas. The Liberty Mine near Tatum showcases the persisting modern importance of coal in life in Texas, used for generating electricity. Covered by the "overburden," the layer of soil just above the deposits, coal is found relatively close to the surface, marking it as an enduring byproduct of mining and excavation as it has been for at least two centuries. Source: Creator: Andrew D. Brosing Date: 2015
Oil Derricks on Spindletop Hill, ca. 1901
Oil Derricks on Spindletop Hill, ca. 1901 Following the discovery of oil beneath the Spindletop salt dome in 1901, the Texas Oil Boom and birth of the petroleum industry formally occurred. Erection of oil derricks covered what was once an area unremarkable save for natural gas seeps, heralding a shift to a new industrial age. Source: Creator: Texas Energy Museum


Samuel House, “The Geological Bounties of Texas,” East Texas History, accessed May 26, 2024,