PDF Publication Title:
Text from PDF Page: 027
Minerals 2020, 10, 284 27 of 34 5.2. Groundwater Flow to Playa Center For discharging playas in Death Valley, California, and Dixie Valley, Nevada, [24] suggested that permeability contrast between playa clays and alluvial fan sands and gravels causes groundwater from alluvial fans to discharge at the edge of the playa though phreatophytes and not flow to the playa center. They indicated that the playas are wet because of continual run-on of surface water to the playa during rainfall events that then seeps into the playa surface and evaporates concentrating the water over time. They further suggested that this process is true for all wet playas. However, this hypothesis is not consistent with salt precipitation patterns. As surface freshwater arrives on the playa it would dissolve any salts that had precipitated previously, but the composition of the incoming water would always be essentially the same and contain higher HCO3 concentrations, because HCO3 is the dominant anion in global river water [69]. This would mean that carbonate minerals would form first in the center of the playa. After carbonate precipitation gypsum would form and then halite. This sequence of precipitation would be vertically stacked in the basin. In Bristol Trough playas, this is not seen in any of the cores, and in fact this sequence is seen laterally most prominently in the BDL basin. Carbonates form mostly in vadose zone calcretes in the fans surrounding the basin, gypsum forms at the transition from alluvial fan to playa clays, and halite forms in the center of the basin (at BDL). Although there are minor amounts of calcite and gypsum in the playa clays (<10%) possibly from run on events, the bulk of these minerals are formed on the edges of the playa. As has been demonstrated in previous work (25–27) the lack of HCO3 and SO4 in the playa center brine at BDL and CDL must be caused by the precipitation of carbonate and sulfate minerals before they enter the center of the playa because these minerals are not present in the basin center. If the playa center brine was formed solely from geothermal fluids similar to Salton Sea brines entering only in the center of the basin, the chemistry of the playa brines would have higher trace element concentrations (Pb, Fe, Mn, in particular) and likely higher Li concentrations. Unevaporated Salton Sea brines have 200–400 ppm Li [42]. In addition, although the Salton Sea brines appear chemically similar to the brines discussed here (Table 1), the milliequivalent ratio of Na:Ca in Salton Sea brines is approximately 1.7 whereas in BDL and CDL brines it is approximately 5 or higher. Finally, K and Mg concentrations Salton Sea brines are approximately 11–16 g/L and 20–74 mg/L, respectively, whereas Bristol Trough brines have K concentrations between <1 and 4.1 g/L and Mg concentrations between 0.5 and 3.5 g/L (data in [12,13]), which are much lower and the opposite of Salton Sea brines (Table 1). Precipitation of clays cannot account for these differences (see below). Lowenstein et al. [15] suggested that Long Valley Caldera springs contributed to the major ion composition of Searles lake in the past, but this geothermal water is not similar to Bristol Trough brines (Table 1). Geothermal water from the Long Valley Caldera is not a likely to be the source for the Bristol Trough brines because even during the wet Pleistocene epoch, the river system that started in the Long Valley Caldera and flowed to Death Valley did not overflow into Bristol Dry Lake [68]. It appears there is no individual source that can completely account for the chemistry of BDL and CDL brines. It is possible that there is a mixture of the different fresh water and geothermal sources. However, correlations of most solutes are consistent (Figure 8), indicating that the source(s) of the fluids come from the edge of the basins and not from the basin centers. Although the chemistry of the alluvial fan porewater is best characterized in the northern Bristol Trough, it is clear that there is little fresh water near BDL. Yet there is abundant fresh/brackish water in Fenner Valley and in the fans to the north of DDL. Based on the observation that the greatest salinity occurs at BDL and playa brines are progressively less saline from CDL to DDL, it appears that BDL is the only completely closed playa within the trough. Extensive halite deposits occur at BDL down to 500 m bls, whereas CDL and DDL only have limited halite within the upper 10 m of the surface [6–8,28]. This indicates that BDL brine has lost substantial Na and Cl to halite precipitation, whereas CDL and DDL brines have not, and that BDL has undergone closed basin evaporation to a greater extent than CDL and DDL. The similarity in brine chemistry between BDL and CDL suggests that they either have been connected as one lake basin at certain times, or that there is a subsurface connection between the basinsPDF Image | Bristol Dry Lake Brine Compared to Brines from Cadiz
PDF Search Title:
Bristol Dry Lake Brine Compared to Brines from CadizOriginal File Name Searched:
minerals-10-00284-v2.pdfDIY PDF Search: Google It | Yahoo | Bing
Product and Development Focus for Infinity Turbine
ORC Waste Heat Turbine and ORC System Build Plans: All turbine plans are $10,000 each. This allows you to build a system and then consider licensing for production after you have completed and tested a unit.Redox Flow Battery Technology: With the advent of the new USA tax credits for producing and selling batteries ($35/kW) we are focussing on a simple flow battery using shipping containers as the modular electrolyte storage units with tax credits up to $140,000 per system. Our main focus is on the salt battery. This battery can be used for both thermal and electrical storage applications. We call it the Cogeneration Battery or Cogen Battery. One project is converting salt (brine) based water conditioners to simultaneously produce power. In addition, there are many opportunities to extract Lithium from brine (salt lakes, groundwater, and producer water).Salt water or brine are huge sources for lithium. Most of the worlds lithium is acquired from a brine source. It's even in seawater in a low concentration. Brine is also a byproduct of huge powerplants, which can now use that as an electrolyte and a huge flow battery (which allows storage at the source).We welcome any business and equipment inquiries, as well as licensing our turbines for manufacturing.CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)