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Analysis of Landsat and Seasat imagery reveals several structural and geobotanical anomalies in the northwestern lower peninsula of Michigan. Integrating these surface anomalies with regional cross-sections and geophysical studies shows that they lie along predictable subsurface trends. These trends control hydrocarbon migration and accumulation; anomalies occur in both producing and untested portions of the trends. Subsequent to the acquisition and analysis of the satellite data, several "untested" areas have been drilled and successfully completed, suggesting that the anomalies are associated with hydrocarbon microseepage. The geobotanical and structural characteristics of Michigan are strongly affected by the last stage of Pleistocene glaciation. In moving through this portion of Michigan, the ice was deflected by a series of topographic features related to subsurface highs. This is indicated by the concave bends in the Port Huron and Manistee moraines, as well as the glacial lake terraces that formed along the edges of the northern topographic high as the ice retreated. The structural interpretation suggests that a large patch reef system may have existed in the northern portion of the study area during deposition of the Devonian Traverse Formation and the Silurian Niagara Group. The Traverse Formation underlies the Antrim Shale that outcrops below the glacial drift of the area. A large patch reef system would account for the differential movement of the ice since the associated limestones would be more resistant to erosion than the surrounding shales. In comparing the location of the geobotanical anomalies with the glacial deposits, an interesting interaction is revealed: over 75% of the anomalies are located in the more porous and permeable outwash deposits. Furthermore, every vegetation anomaly is associated with a lineament or lineament intersection on the structural interpretation. The geobotanical anomalies are also very transient. They appear only during the initial "leaf-out" in the spring and as areas of pre-senesence in the fall. During the summer months they are not visible. Apparently the microseepage visibly affects the vegetation only at those times of the year when the vegetation is in a natural state of flux or stress. This vegetation "stressing" also seems to be limited to the larger species of trees that have extensive root systems. This suggests that only the larger trees sample the deeper, more highly affected soil horizons.
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