40 Evaporite MineralsDominant Evaporite Minerals include: Carbonates, Chlorides, Sulphates, Borates & NitratesMarine systems dominantly produce Carbonates, Chlorides & SulphatesArid Terrestrial Systems produce unusual diagenetic minerals in pore spaces and beds of Borates & Nitrates additional to the Carbonates, Chlorides & Sulphates.Additional to the unusual Continental anion Chemistry, salts of metals form some unusual brine minerals, Cu, Ni, Zn, Pb, Ag and even (NH4)+ !Salts precipitate in inverse order depending on their solubility. (solubility in strong/odd brines is empirical)Salts in vadose zone porosity are important in soils
41 Textures in Resedimented Evaporites, Italy Messinian (~5Ma) Mediterranean Basin
42 Evaporite Minerals Carbonates: Mineral Formula Calcite CaCO3 Dolomite CaMg (CO3 )2Siderite FeCO3Natrite Na2CO3 & Natron•6(H2O)Trona Na3(CO3)(HCO3)•2(H2O)(Green River, WY; Lake Magadi, Kenya)
47 Cyclic & Crossbedded Devonian Halite, Goderich ON Q1) Cyclic evaporation and minor recharge. Q2) Brine is denser and has more momentum than typical sea water. Pure Halite has a S.G. of 2.07, lighter than calcite or quartz. As a result, lower current velocities might produce X-bedded halites just as shallow but also in deeper, quieter water than carbonate shoals or siliciclastic bars.In what kind of Basin would “Cyclic Halite” beds form?In what sort of flow regime would Halite X-beds form?
48 Evaporite Minerals Sulphates: Mineral Formula Anhydrite CaSO4 Gypsum CaSO4· 2H2OLangbeinite K2Mg2(SO4)3Polyhalite K2Ca2Mg(SO4)4 · 2H2OKieserite MgSO4· H2OKainite KMg(SO4)Cl · 3H2O
49 Interbedded Gypsum & Calcsiltite, Silurian Somerset Island ?Solutional Collapse
52 Evaporite Minerals Nitrates: Mineral Formula Niter KNO3 Nitratine NaNO3· 2H2ONitrocalcite Ca(NO3)2 · 4H2ONitrobarite Ba(NO3)2Gerhardtite Cu2(NO3)(OH)3Some of these were done from memory so you may wish to check Mindat.org
55 Evaporite Minerals Borates: Mineral Formula Boracite Mg3[ClB7O13 ] Borax Na2[B4O7]2 · 10H2OColemanite Ca[B3O4(OH)3] · 3H2OHydroBoracite CaMg [B3O4(OH)3]2 · 3H2OLarderellite (NH4 )B5O6(OH)4Tincalconite Na2[B4O7] · 5H2OUlexite NaCa[B5O6(OH)6]· 5H2OSome of these were done from memory so you may wish to check Mindat.org
Your consent to our cookies if you continue to use this website.