In a message dated 1/29/2008 3:18:08 P.M. Central Standard Time, [email protected] writes:
Are there any caves in Fort Bend County? No, though there was a large sinkhole that formed by salt collapse. BLUE RIDGE SINKHOLE (FB001) Sinkhole Length: 150 ft. (45 m) Depth: 35 ft. (11 m) Owner: (?) Quadrangle: Almeda and Missouri City 7.5” Description: A sinkhole measuring 150 feet wide and 35 feet deep suddenly formed on 24 December 1949 southeast of the town of Missouri City, Texas. The collapse damaged several structures at the Gulf Salt Company salt mining facility. History: “Prior to the collapse, which occurred on December 24, 1949, Hanna (1953, p. 277) reports that machinery at the plant began to malfunction. This was unexpected because the plant had been shut down for the Christmas holiday. On December 24, the ground above the solutioned cavity started to sink. Hanna reports that the subsidence was centered around the pipe shaft through which the fresh water and brine was being pumped in and out. By December 28, when Hanna (1953, p. 277) visited the site, the sinkhole had stabilized with a diameter of 150 feet and an approximate depth of 35 feet. Since the sinkhole was partially filled with water or brine, the actual depth was hard to establish. During Hanna's visit, he noted that surface cracks were found encircling the sinkhole. Structural damage to plant buildings also occurred. The buildings that were damaged were located in the area directly above the solution cavity and some portions of the plant fell in with the overlying strata. ”- (Coates, et al, 1981). Geology: The area overlies the shallowly buried Blue Ridge Salt Dome which for decades has been actively mined for salt. Wells are drilled into the salt for water injection and brine subsequently pumped out. This has resulted in the creation of dissolution voids, one of which apparently collapsed, causing the formation of the sinkhole. Bibliography: Coates, G. K., C.A. Lee, W.C. McClain, and P.E. Senseny. 1981. Failure of man-made cavities in salt and surface subsidence due to mining. Sandia National Laboratories Report SAND81-7145, Albuquerque, NM, 136 pp. Hanna, M.A. 1953. Fracture porosity in Gulf Coast. Am. Assoc. Petroleum Geologists Bull., 37(2):266-281. Neal, James. T. 1994. Surface features indicative of subsurface evaporite dissolution: implications for storage and mining. Solution Mining Research Institute, 1994 Spring Meeting, Houston, Texas, 25-27 April 1994. _http://ug-sprtech.sandia.gov/pub/General/SNL_Geotech_General/SMRI94_Surface_F eatures_Dissolution_Implications_Storage.pdf_ (http://ug-sprtech.sandia.gov/pub/General/SNL_Geotech_General/SMRI94_Surface_Features_Dissolution_Implications _Storage.pdf) **************Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489
