Land & Wildlife - Texas - page 739

TEXAS GEOLOGY & BLACK GOLD
The most exciting geological aspect of Texas is why there's oil. The sticky black stuff sits beneath Texas, south-
ern Mississippi and Alabama, and Louisiana; there is heaps of it under the Gulf of Mexico near all these states, as
well as the Mexican states of Tamaulipas, Veracruz and Tabasco - all areas surrounding the huge sedimentary
basin that forms the Gulf of Mexico.
Evolving for more than 100 million years, the basin consists of a thick sequence of sedimentary rocks. As the
sedimentary material makes its way deeper into the earth, it's subjected to a great deal of pressure and heat -
enough to convert much of the organic debris (the remains of plants and animals that are always part of sediment-
ary material) into petroleum. You know, to refine for gasoline, to fill up those ubiquitous Texas trucks needed to
traverse these great distances… See, every issue here comes back, inexorably, to the land.
Petroleum flows freely, but tends to collect into large masses that migrate into traps - so named because rocks
or other impermeable materials catch the oil - where it forms pools. Pools are what oil explorers are after. Under
Texas, salt domes (which are just what they sound like) act as traps; when they're pierced, oil that has been
trapped beneath gushes forth. That's what happened when early 1900s prospectors first struck oil at Spindle Top
in Beaumont, and at the World's Richest Half Acre in Kilgore. Gushers, however, are rare these days, as oil ex-
ploration has become extremely sophisticated.
These days it's the Eagle Ford shale, found south of Hill Country, that's making news. This late Cretaceous
rock formation is mineral rich, with oil and gas deposits. The high percentage of carbonate makes the formation
more brittle, and therefore responsive to hydraulic-fracturing (or fracking), which is used to extract it. This some-
what controversial process is fueling a growing economy in once moribund south-central Texas.
Parks & Land Protection
Texas has two national parks, Big Bend and Guadalupe Mountains, as well as 16 national
preserves ( www.nps.gov ) , 55 state parks ( www.tpwd.state.tx.us ) and four state forests. Oil
drilling and natural gas exploration is allowed, but managed, in some of the natural pre-
serves and on public lands. As well as providing opportunities for recreational activities,
many of the preserves offer interpretive activities and educational programs.