Structural and chemical modification of nontronite associated with microbial Fe(III) reduction: Indicators of “illitization”

Clay Mineralogical Characteristics of Sediments Deposited during the Late Quaternary in the Larsen Ice Shelf B Embayment, Antarctica

“…These values with SD (0.53 ± 0.03, 0.52 ± 0.06, 0.56 ± 0.03, and 0.58 ± 0.05, respectively) showed a variation between those values from U1-2 and U3-4, suggesting different depositional conditions or likely different sources. In addition, bio-reduced smectite showed an Al/Si difference of 0.02-0.05, compared with the non-reduced smectite [49], indicating that small variation in Al/Si may respond to the geochemical alteration of minerals as observed in the present study. However, the present study is for the natural sediments that may have more factors to modify the illite composition, such as chemical/physical weathering as well as microbial alteration [5,50].…”

“…Structural differences in the two groups of illite were measured in the Bragg's reflection of the SAED patterns, displaying diffused, randomly ordered (U3-4, Figure 4c,d), and discretely ordered patterns (U1-2, Figure 4a,b). Modification of illite crystal structures can be ascribed to the Fe-redox reaction that changes the lattice energy, causing Fe to be released from the structure [49]. Indeed, the content of structural Fe in illite for U3-4, the oxygen-limited conditions, is shown to be less than the content in U1-2, which was deposited in more oxygen-rich conditions when the open marine condition reached.…”

Low-temperature feldspar and illite formation through bioreduction of Fe(III)-bearing smectite by an alkaliphilic bacterium

“…This S-I reaction was interpreted to occur as a result of microbial reduction of structurally-coordinated Fe(III) in smectite by DIRB, reductive dissolution of smectite, and subsequent formation of illite (Kim et al, 2004). A growing body of work has subsequently suggested that a wide variety of DIRB (e.g., Shewanella strains: Zhang et al, 2007a;Gaines et al, 2009;Jaisi et al, 2011;Koo et al, 2014;Liu et al, 2014;Thermoanaerobacter ethanolicus: Zhang et al, 2006, 2007bThermus scotoductus: Jaisi et al, 2011) and sulfate-reducing bacteria (SRB) (Liu et al, 2012) catalyze illite formation via a similar mechanism. In addition to illite, some other secondary minerals have also been observed as a result of bioreduction of iron-bearing smectite, such as amorphous silica globules (Dong et al, 2003;O'Reilly et al, 2005;Zhang et al, 2007b;Liu et al, 2011Liu et al, , 2014, high charge smectite with increased Al/Si ratios (O'Reilly et al, 2005;Zhang et al, 2007a;Liu et al, 2011), and other various byproducts (e.g., vivianite, siderite, calcite, and iron sulfide particle), depending on medium and buffer type (Li et al, 2004;Dong et al, 2009;Jaisi et al, 2011).…”

Quantitative Identification of the Annealing Degree of Apatite Fission Tracks Using Terahertz Time Domain Spectroscopy (THz-TDS)

“…Terahertz spectroscopy, a rapidly developing spectroscopic technique bridging the gap between microwave and infrared (IR) radiation, is becoming increasingly widely applied in petroleum geology. The latest applications mainly focus on clay mineral structure, 19 lithology identification, 20 kerogen pyrolysis, 21 and coal, oil, and gas components. [22][23][24] Terahertz time domain spectroscopy (THz-TDS) is a non-ionizing, non-contact transmission spectrum detection technique that can provide abundant phase and amplitude information of anomalous lattice vibrations caused by componential and structural changes of materials and therefore suitable for fission-track research.…”