Shi Zhenya

Authigenic carbonates are widely distributed in marine sediments, microbes, and anaerobic oxidation of methane (AOM) play a key role in their formation. The authigenic carbonates in marine sediments have been affected by weathering and diagenesis for a long time, it is difficult to understand their formation process by analyzing the samples collected in situ. A pore water environment with 10 °C, 6 MPa in the marine sediments was built in a bioreactor to study the stages and characteristics of authigenic carbonates formation induced by microbes. In experiments, FeCO3 is formed preferentially, and then FeCO3-MgCO3 complete isomorphous series and a small part of CaCO3 isomorphous mixture are formed. According to this, it is proposed that the formation of authigenic carbonates performed by AOM and related microbes needs to undergo three stages: the rise of alkalinity, the preferential formation of a carbonate mineral, and the formation of carbonate isomorphous series. This work provides experimental experience and reference basis for further understanding the formation mechanism of authigenic carbonates in marine sediments.

This paper deals with 1 new species of the Eriococcusinhabiting Encyrtid colleted from Henan Province of China; Microtetys eriococci sp.nov. Type specimens are kept in the Insect Specimen Room the Department of Plant Protection. Bioengineering College of Henan Agricultural University. The new species is similar to Microterys danzigae Sugonjaev, but its body is yellowish brown, with antennal scape oval, about 2.5 times as long as wide, fifth sixth funicle segments white, and fore wings almost wholly infuscate, except apical margine hyaline. Holotype ♀ (B17 09 01),Paratypes 10 ♀ ♀ (B17 09,Q90 05 03), Parasites of Eriococcus transverses, June 23,1985,Zhengzhou, Henan Province, colleted by Xu Guang.