Pedersen K, Ekendahl S, Tullborg E L, Furnes H, Thorseth I, Tumyr O
Department of General and Marine Microbiology, Goteborg University, Sweden.
Geology. 1997 Sep;25(9):827-30. doi: 10.1130/0091-7613(1997)025<0827:eoalam>2.3.co;2.
The results of electron-microscopy investigations of calcite precipitated in a water-conducting fracture in a ca. 1800 Ma granitic rock from 207 m below sea level at the island of Aspo on the southeastern (Baltic) coast of Sweden are compared with measurements of carbon, oxygen, and sulfur isotope composition of the calcite and embedded pyrite. Parts of the calcite had extremely low delta 13C values, indicative of biological activity, and contained bacteria-like microfossils occurring in colonies and as typical biofllms. X-ray microanalysis demonstrated these fossils to be enriched in carbon. Our results provide evidence for ancient life in deep granitic rock aquifers and suggest that the modern microbial life found there is intrinsic. Modeling historical and present geochemical processes in deep granitic aquifers should, therefore, preferably include biologically catalyzed reactions. The results also suggest that the search for life on other planets, e.g., Mars, should include subsurface material.
对在瑞典东南部（波罗的海）海岸阿斯波岛海平面以下207米处一块约18亿年前花岗岩的导水裂缝中沉淀的方解石进行电子显微镜研究的结果，与该方解石及嵌入其中的黄铁矿的碳、氧和硫同位素组成测量结果进行了比较。部分方解石的δ13C值极低，表明存在生物活动，并且含有以菌落形式出现以及作为典型生物膜存在的类似细菌的微化石。X射线微分析表明这些化石富含碳。我们的结果为深部花岗岩含水层中的古代生命提供了证据，并表明在那里发现的现代微生物生命是固有的。因此，对深部花岗岩含水层中历史和当前地球化学过程进行建模时，最好应包括生物催化反应。结果还表明，在其他行星（如火星）上寻找生命时，应包括地下物质。
