# Goliad Formation

The Goliad Formation (Tg) is a geologic formation in Texas. It preserves fossils dating back to the Serravallian to earliest Pliocene stages (Clarendonian, Hemphillian and earliest Blancan in the NALMA classification) of the Neogene period, including the gomphothere Blancotherium among many other fossil mammals, reptiles, birds and fish.
The formation hosts uranium deposits and forms the Evangeline aquifer underneath the city of Houston.

## Description

The Goliad Formation was described by Plummer in 1933, as consisting of three members; the Lapara Sand, overlain by the Lagarto Creek Beds, in turn overlain by the Labahia Beds with outcrop thicknesses ranging from 35 to 200 feet (11 to 61 m). The Goliad Formation comprises claystone, sand, sandstone, marl, caliche, limestone, and conglomerates and reaches in certain areas a thickness of 180 metres (590 ft). The formation overlies the Fleming Formation and dates from the Clarendonian to the earliest Blancan. In the southwest of its range, the formation overlies the Catahoula and Gueydan Formations. The Goliad Formation is recognized regionally across the Texas coastal plain as an interval of dominantly fluvial siliciclastic strata that overlies the Miocene Fleming Formation and underlies Pleistocene terrace deposits. The formation is now interpreted as a basinward-thickening progradational wedge of Middle and Late Miocene age. Stratigraphic thicknesses in outcrop range from 60 to 120 metres (200 to 390 ft), but offshore the interval thickens to as much as 365 to 425 metres (1,198 to 1,394 ft).
Together with the Catahoula, Fleming and Oakville Formation, the Goliad Formation is part of the Gulf Coast aquifer, an extensive artesian aquifer that produces water primarily for irrigation and municipalities. The Evangeline aquifer is hosted by the Goliad Formation underlying the city of Houston. The formation hosts uranium deposits in the South Texas Uranium Province and is mined for caliche in Hidalgo County, Texas.

## Fossil content

Tertiary mammal fossils from South Texas were first reported by Dumble (1894) as coming from the Lapara division, later the Lapara Beds (Dumble, 1903).
The following fossils have been reported from the formation:
| Group | Taxa |
| Mammals | Aelurodon taxoides |
| Mammals | Blancotherium buckneri |
| Mammals | Calippus martini |
| Mammals | Calippus placidus |
| Mammals | Calippus regulus |
| Mammals | Ceratogaulus rhinocerus |
| Mammals | Cormohipparion ingenuum |
| Mammals | Cranioceras teres |
| Mammals | Dinohippus subvenus |
| Mammals | Hipparion tehonense |
| Mammals | Hypohippus affine |
| Mammals | Hypohippus affinis |
| Mammals | Ischyrocyon gidleyi |
| Mammals | Leptocyon vafer |
| Mammals | Megatylopus primaevus |
| Mammals | Neohipparion affine |
| Mammals | Nothotylopus camptognathus |
| Mammals | Pliohippus pernix |
| Mammals | Procamelus grandis |
| Mammals | Procamelus occidentalis |
| Mammals | Prosthennops xiphidonticus |
| Mammals | Protohippus supremus |
| Mammals | Protolabis coartatus |
| Mammals | Pseudhipparion curtivallum |
| Mammals | Pseudoceras skinneri |
| Mammals | Ramoceros ramosus |
| Mammals | Synthetoceras tricornatus |
| Mammals | Teleoceras major |
| Mammals | Ustatochoerus medius novomexicanus |
| Mammals | Protolabis cf. yavapaiensis |
| Mammals | Ustatochoerus cf. medius |
| Mammals | Aepycamelus sp. |
| Mammals | Amphicyon sp. |
| Mammals | Aphelops sp. |
| Mammals | Bison sp. |
| Mammals | Blastomeryx sp. |
| Mammals | Calippus sp. |
| Mammals | Glyptodon sp. |
| Mammals | Hypohippus sp. |
| Mammals | Hippotherium sp. |
| Mammals | Hypolagus sp. |
| Mammals | Megatylopus sp. |
| Mammals | Merychippus sp. |
| Mammals | Merychyus sp. |
| Mammals | Merycodus sp. |
| Mammals | Nannippus sp. |
| Mammals | Neohipparion sp. |
| Mammals | Pliauchenia sp. |
| Mammals | Pliohippus sp. |
| Mammals | Procamelus sp. |
| Mammals | Prosthennops sp. |
| Mammals | Protolabis sp. |
| Mammals | Teleoceras sp. |
| Mammals | cf. Domninoides sp. |
| Mammals | cf. Eucyon sp. |
| Mammals | cf. Gomphotherium sp. |
| Mammals | Amphicyoninae indet. |
| Mammals | Merycodontinae indet. |
| Mammals | Protoceratinae indet. |
| Mammals | Tayassuinae indet. |
| Mammals | Antilocapridae indet. |
| Mammals | Canidae indet. |
| Mammals | Equini indet. |
| Mammals | Palaeomerycidae indet. |
| Mammals | Protoceratidae indet. |
| Mammals | Rhinocerotidae indet. |
| Mammals | Rodentia indet. |
| Mammals | Ruminantia indet. |
| Mammals | cf. Mustelidae indet. |
| Birds | cf. Anserinae indet. |
| Birds | Aves indet. |
| Reptiles | Alligator cf. mississippiensis |
| Reptiles | Apalone sp. |
| Reptiles | Hesperotestudo sp. |
| Reptiles | Testudo sp. |
| Reptiles | Trionyx sp. |
| Reptiles | cf. Gopherus sp. |
| Reptiles | cf. Mycteria sp. |
| Reptiles | cf. Terrapene sp. |
| Reptiles | cf. Trachemys sp. |
| Reptiles | Emydidae indet. |
| Fish | Pylodictis olivaris |
| Fish | Ictalurus cf. lambda |
| Fish | Ameiurus sp. |
| Fish | Lepisosteus sp. |