Papers by Matthew DeCesare
ABSTRACT
Bookmarks Related papers MentionsView impact
The reaction of nitrite (NO 2 −) and nitrate (NO 3 −) on nanometer-sized FeS particles was invest... more The reaction of nitrite (NO 2 −) and nitrate (NO 3 −) on nanometer-sized FeS particles was investigated in alkaline (initial pH=10.3) solutions at reaction temperatures of 22, 70, and 120 °C using in situ attenuated total reflection Fourier transform infrared spectros-copy (ATR-FTIR) and fluorescence spectroscopy that allowed an analysis of adsorbate complexation on the FeS and reaction product in the aqueous phase, respectively. ATR-FTIR showed that NO was a surface-bound intermediate on FeS during its exposure to NO 2 − at all three reaction temperatures. Ammonia/ammonium (NH 3 /NH 4 +) product was also produced when FeS was exposed to NO 2 − at the 70 °C and 120 °C reaction temperatures. Activation of NO 3 − to form surface-bound NO was experimentally observed to occur at 120 °C on FeS, but not at the lower reaction temperatures. Furthermore, NH 3 /NH 4 + product in the aqueous phase was only present during the reaction of FeS with NO 3 − at the highest temperature used in this study.
Bookmarks Related papers MentionsView impact
A newly recognized carbonate preservation event (CPE) dated between 11 and 12 Ma was identified i... more A newly recognized carbonate preservation event (CPE) dated between 11 and 12 Ma was identified in Hole U1361A during Integrated Ocean Drilling Program Expedition 318 in the Southern Ocean based on CaCO 3 content and the preservation of foramin-iferal tests. High carbonate content occurs within the interval between 311.60 and 349.99 meters below seafloor, whereas CaCO 3 content was typically near 1 wt% for the rest of the core. In addition , benthic and planktonic foraminifers were relatively abundant. However, stable isotope measurements carried out within this interval contained unrealistic values, which we ascribe to postdepositional diagenetic alteration by the release of methane. This prohibited quantification of temperature, ice volume, and salinity. The CPE identified at Hole U1361A was also observed at Ocean Drilling Program Site 689, which is correlated to the Mi5 glaciation. We hypothesize that this Southern Ocean CPE and the dia-genetic alteration of foraminifers were due to both the Mi5 glacia-tion and reorganization of ocean circulation.
Bookmarks Related papers MentionsView impact
Uploads
Papers by Matthew DeCesare