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Pervasive dolomites occur preferentially in the stromatoporoid biostromal (or reefal) facies in the basal Devonian (Givetian) carbonate rocks in the Guilin area, South China. The amount of dolomites, however, decreases sharply in the overlying Frasnian carbonate rocks. Dolostones are dominated by replacement dolomites with minor dolomite cements. Replacement dolomites include: (1) fine to medium, planar-e floating dolomite rhombs (Rd1); (2) medium to coarse, planar-s patchy/mosaic dolomites (Rd2); and (3) medium to very coarse nonplanar anhedral mosaic dolomites (Rd3). They post-date early submarine cements and overlap with stylolites. Two types of dolomite cements were identified: planar coarse euhedral dolomite cements (Cd1) and non-planar (saddle) dolomite cements (Cd2); they post-date replacement dolomites and predate late-stage calcite cements that line mouldic vugs and fractures. The replacement dolomites have d 18 O values from )13AE7 to )9AE7& VPDB, d 13 C values from )2AE7 to + 1AE5& VPDB and 87 Sr/ 86 Sr ratios from 0AE7082 to 0AE7114. Fluid inclusion data of Rd3 dolomites yield homogenization temperatures (T h ) of 136-149°C and salinities of 7AE2-11AE2 wt% NaCl equivalent. These data suggest that the replacive dolomitization could have occurred from slightly modified sea water and/or saline basinal fluids at relatively high temperatures, probably related to hydrothermal activities during the latest Givetian-middle Fammenian and Early Carboniferous times. Compared with replacement dolomites, Cd2 cements yield lower d 18 O values ()14AE2 to )9AE3& VPDB), lower d 13 C values ()3AE0 to )0AE7& VPDB), higher 87 Sr/ 86 Sr ratios ( 0AE7100) and higher T h values (171-209°C), which correspond to trapping temperatures (T r ) between 260 and 300°C after pressure corrections. These data suggest that the dolomite cements precipitated from higher temperature hydrothermal fluids, derived from underlying siliciclastic deposits, and were associated with more intense hydrothermal events during Permian-Early Triassic time, when the host dolostones were deeply buried. The petrographic similarities between some replacement dolomites and Cd2 dolomite cements and the partial overlap in 87 Sr/ 86 Sr and d 18 O values suggest neomorphism of early formed replacement dolomites that were exposed to later dolomitizing fluids. However, the dolomitization was finally stopped through invasion of meteoric water as a result of basin uplift induced by the Indosinian Orogeny from the early Middle Triassic, as indicated by the decrease in salinities in the dolomite cements in veins (5AE1-0AE4 wt% NaCl equivalent). Calcite cements generally yield the lowest d 18 O values ()18AE5 to )14AE3& VPDB), variable d 13 C values ()11AE3 to )1AE2& VPDB) and high T h values (145-170°C) and low salinities (0-0AE2 wt% NaCl equivalent), indicating an origin of high-temperature, dilute fluids recharged by meteoric water in the course of basin uplift during the Indosinian Orogeny. Faults were Sedimentology

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The conductance method has been used to measure the density of interface states of the ZnS/Hg0.775Cd0.225Te metal-insulator-semiconductor (MIS) system with three different HgCdTe surface treatments. It is found that the density of fast interface states increases from ∼1011 eV−1 cm−2 at the conduction-band minimum to ∼1013 eV−1 cm−2 near the valence-band maximum. In addition, the interface states located in the lower part of the band gap communicate with the valence band so efficiently that the effective band gap is reduced. Our observations explain why the p-type MIS photodiode is superior to the n-type version in terms of breakdown voltage and storage time.