Appendices & Glossary - Botanical Research Institute of Texas

1208 APPENDIX TEN/EAST TEXAS AS A UNIQUE HABITAT
the region was a near shore environment, an extraterrestrial object (e.g., meteorite) impacted into soft,
unconsolidated sediments, producing a 13 km diameter impact crater. Subsequently buried by sediments,
and later partially uncovered by erosion, the only present day surface exposure of the crater is
an uplifted area at the crater’s center—a 1.2 km diameter outcrop of blocks of Cretaceous Pecan Gap
limestone (Taylor group) in a matrix of sand and clay. The presence of this anomalous limestone at the
surface represents a vertical uplift of the Cretaceous rocks at least 1120 m (more than half a mile), and
is an indication of the tremendous energy released when an object moving at incredible speed impacted
the area (Gibson & Sharpton 1989; Gibson 1990; McHone & Sorkhabi 1994; Buchanan et al.
1998; Wong et al. 2001). The unusual surface outcrop of limestone rocks is potentially interesting botanically—e.g.,
the presence of unexpected calciophilic species.
East Texas is thus a unique habitat from numerous perspectives. When it is considered that within
the last 150 years virtually all of the Pineywoods was cut for timber and virtually all of the Blackland
Prairie was destroyed for cotton production and other uses, many questions, both practical and philosophical,
come to mind regarding the use of natural resources. Is it not our responsibility to preserve a
minute fraction of this wonderful and unique natural heritage? How can we justify destroying absolutely
everything in the name of progress and economic prosperity? What will future generations of
Texans say about the actions of those alive today? Are we the stewards of the natural world or merely
its exploiters?