The detection of carbonate in the martian soil at the Phoenix Landing site: A laboratory investigation and comparison with the Thermal and Evolved Gas Analyzer (TEGA) data     

B. Sutter  W.V. Boynton  D.W. Ming  P.B. Niles  R.V. Morris  D.C. Golden  H.V. Lauer  C. Fellows  D.K. Hamara  S.A. Mertzman 《Icarus》2012,218(1):290-296

Data collected by Phoenix Lander’s Thermal and Evolved Gas Analyzer (Phoenix-TEGA) indicate carbonate thermal decomposition at both low and high temperatures. The high-temperature thermal decomposition is consistent with calcite, dolomite, or ankerite, (3–6 wt.%) or any combination of these phase or, presumably, solid solutions of these phases having intermediate composition. The low-temperature thermal decomposition is consistent with the presence of magnesite or siderite, their solid solutions, or any combination of magnesite and siderite, and possibly other carbon-bearing phases (e.g., organics). The carbonate concentration for the low temperature release, assuming magnesite–siderite, is ～1.0 wt.%. This revised interpretation of the Phoenix-TEGA data resulted from new laboratory measurements of carbonate decomposition at a Phoenix-like 12 mbar atmospheric pressure. Phoenix carbonate was inherited in ejecta from the Vastitas Borealis and Scandia regions, inherited from material deposited by aeolian processes, and/or formed in situ at the Phoenix Landing site (pedogenesis). Inherited carbonate implies multiple formation pathways may be represented by carbonates at the Phoenix Landing site. Soil carbonates and associated moderate alkalinity indicate that the soil pH is favorable for microbial activity at the Phoenix Landing site and presumably throughout the martian northern plains.  相似文献   

Evaluating Hyperspectral Imager for the Coastal Ocean (HICO) data for seagrass mapping in Indian River Lagoon,FL     

Hyun Jung Cho  Igor Ogashawara  Deepak Mishra  Joseph White  Andrew Kamerosky  Lori Morris 《地理信息系统科学与遥感》2014,51(2):120-138

Differentiation between benthic habitats, particularly seagrass and macroalgae, using satellite data is complicated because of water column effects plus the presence of chlorophyll-a in both seagrass and algae that result in similar spectral patterns. Hyperspectral imager for the coastal ocean data over the Indian River Lagoon, Florida, USA, was used to develop two benthic classification models, Slope_RED and Slope_NIR. Their performance was compared with iterative self-organizing data analysis technique and spectral angle mapping classification methods. The slope models provided greater overall accuracies (63–64%) and were able to distinguish between seagrass and macroalgae substrates more accurately compared to the results obtained using the other classifications methods.  相似文献   

Magnetic crustal character in Central Ireland     

P. Morris  M. D. Max 《Geological Journal》1995,30(1):49-67

The simplest magnetic model for the upper 20 km of crust in central Ireland is of two layers. A thin, weakly magnetic upper layer carrying a number of magnetic bodies that can be related to surface geology overlies a magnetic crustal zone whose gross magnetization increases towards the north. The deeper trace of the lapetus Suture in central Ireland forms the boundary between a more magnetic northern crustal area and a less magnetic southern area. A pre-Carboniferous major dextral offset of this suture boundary occurs in the Limerick area. The suture is traced beneath the Dingle peninsula in the far south-west of Ireland. In east-central Ireland, between the Iapetus Suture and Southern Upland Line, the crust contains a large, south-dipping magnetic body with no surface expression, which produces the Virginia magnetic anomaly. The development of magnetic bodies — in particular, volcanic rocks of Carboniferous age — has been controlled by regional stress patterns. The major volcanic centre at Limerick lies at the intersection of two major Caledonian block fault systems just to the north of the surface trace of the Hercynian Front.  相似文献