White Rock Lake

Because of the tendency of HCs to associate with particles, suspended sediment is likely to be the vehicle for the vast majority of the transport of HCs. Once the sediment settles out of flow and settles to the floor of the receiving water body, it can represent a threat to the ecological community. Benzo[a]pyrene, for example, was not detected in any of 100 storm-event samples in residential sites in the Dallas-Fort Worth area and was detected in less than 5% of samples from commercial and industrial sites (Raines et al., 1997). Yet concentrations of benzo[a]pyrene have increased 20-fold in the Dallas-Fort Worth area, coincident with urban development, based on an age-dated sediment core from White Rock Lake in Dallas (Van Metre et al., 2000). 

Van Metre, P. C., Callender, E., 1997, Water-Quality Trends in White Rock Creek Basin from 1912-1994 Identified Using Sediment Cores from White Rock Lake Reservoir, Dallas, Texas, J. Paleolimnol. 17 239-249. 

Reynolds R. L., Rosenbaum J. G., van Metre P., Tuttle M. L., Callender E. and Golden A. (1999) Greigite (Fe3S4) as an indicator of drought—the 1912-1994 sediment magnetic record from White Rock Lake, Dallas Texas, USA. J. Paleolimnol. 21, 193 -206. 

At the White Lake Cu-Zn sulfide deposit (near Flin Flon, Manitoba) no geochemical signature had been obtained from conventional soil geochemistry. Where the deposit is overlain by 23m of barren rock and 8m of glacial overburden including an upper 1m of impermeable varved clay, a strong characteristic rabbit-ear H anomaly clearly indicates the location of the orebody, as predicted by the electrochemical model (Govett 1976). 

Figure 18.5 Lake Natron in Africa s Great RiftVaiiey is a naturaiiy basic body of water. Water, iaden with dissoived sodium carbonate from surrounding voicanic rocks, drains into the lake but finds no outiet. Evaporation concentrates the mineral leaving a white crust on the surface and strongly alkaline water. 

In the La Cloche Mountain area of Ontario, 24% of lakes surveyed have no fish at all. 56% of these fishless lakes are known to have suffered a reduction in fish species composition. Small-mouth bass, walleye, white suckers, norther pike, lake trout, lake herring, perch and rock bass have been affected. 

The blood at Blood Falls spills out of life, but it s not blood. Like blood, this substance is a form of iron bound to oxygen. In your blood, the protein hemoglobin hosts the iron, but Blood Falls is straight-up iron oxide, similar to rust. I saw some of this chemical last August near Mount Rainier. As we hiked up to Goat Lake, the frozen water looked dirty. The pure white ice was dusted with bright-red powder blown around from the iron-rich rocks surrounding it. The land was red as blood. 

Doyleite is a triclinic aluminium hydroxide mineral with composition Al(OH)3. It occurs as masses of soft white tabular crystals with pearly lustre which form from the weathering of aluminium-rich rocks in tropical climates. Hence, doyleite is often found in bauxites (. v.). Doyleite is closely related to another triclinic form of A1(0H)3, nordstrandite, and the monoclinic polymorphs, gibbsite and bayerite qq.v.), with which it may be found (Chao et al., 1985) it is also related to the orthorhombic dehydrated forms of AIO(OH), boehmite and diaspore qq.v.). Synthetic alu-minimn hydroxide Al(OH)3 is commonly encountered as a substrate for lake pigments. 

Various forms of limestone (particularly chalk) and lime have found abrmdant usage as a pigment either as bases for lakes, or as plain white and whitewash. Naruse (1996) has noted that there is documentary evidence for the use of limestone as a white grormd coating in the consfructionof Kofuku-ji Temple, Japan, in 734 ad. Pedersen (1974) has detected limestone in Argentinian rock art. There is some documentary evidence for the use of travertine as a substrate for lake pigments. 

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