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A continuous floodplain line could not be delineated on the basis of computer analysis of the aircraft collected MSS data. However, the computer analysis did indicate a break between floodplain and non-floodplain within small areas which correlated with one or more floodplain limits established by other methods (i.e., interpretation by the U.S. Army Corps of Engineers, photo interpretation of color infrared aerial photographs, and soils maps generated by the USDA Soil Conservation Service). Although the results of this investigation were somewhat less positive than desired, they do not necessarily indicate that computer analysis of aircraft collected multispectral scanner data could not be useful in the delineation of floodplains. The test area involved in this study has a very complex topography and many land cover types. The slopes range from nearly level to over 35 percent, with greatly varying aspects. The land cover types include urban and residential areas, small agricultural fields, and complex forest stands. Results in a less complex area would most likely be considerably more successful.

A continuous floodplain boundary was drawn on the basis of interpretation of the computer classification of selected Landsat-1 digital MSS data. Within the agricultural and developed portion of the study area, this floodplain correlated quite favorably with the USACE 100-year return period floodplain, which is based on the conventional engineering parameters of streamflow and basin configuration. Within the forested portion of the study area, correlation of the floodplain limits was not as satisfactory. Since the floodplain limit established by remote sensing in the forested area consistently overestimated the USACE 100-year return period floodplain, there is an indication that it could represent the limit of a flood with a return period of more than 100 years. The success realized in this investigation indicates that computer analysis of remotely sensed digital MSS data has the potential of playing a prominent role in the identification and mapping of floodplains. This method could be used to update and verify existing maps or to produce maps in watersheds where none exist and the need for floodplain information to regulate land use is great. The use of remotely sensed digital MSS data would most likely have its greatest application as a tool to complement more conventional floodplain mapping techniques., See also ORSER-SSEL-TR-1-75, AD-A035 279.

The late-kinematic structural architecture of the Flin Flon domain is dominated by a network on anastomosing shear zones formed by compressional deformation during the Proterozoic Trans-Hudson orogeny (ca. 1900-1800 Ma). A number of structurally controlled mesothermal gold deposits occur throughout the region, associated with this shear zone network. The Tartan Lake gold deposit occurs in the Tartan Lake shear zone, at the contact between a layered gabbroic intrusive complex and metavolcanic rocks of the Amisk group (ca. 1875 Ma). Five phases of deformation have been recognised in the Flin Flon region (P1-P5). Mid-greenschist facies peak metamorphic conditions (phase 3) at Tartan Lake are recorded by a mineral assemblage of biotite-actinolite-albite-muscovite-epidote and carbonate in volcaniclastic rocks, along with a well-developed phase 3 schistosity. Early movement of the Tartan Lake shear zone was initiated with phase 3 deformation, during which oblique slip occurred. During phase 4, this shear zone was overprinted by a major regional fold and the shear zone was reactivated by strike-slip movement. Regional phase 3 schistosity is refolded in a series of steeply plunging mesoscopic phase 4 fold closures that were synchronous with the shear zones., The late-kinematic structural architecture of the Flin Flon domain is dominated by a network on anastomosing shear zones formed by compressional deformation during the Proterozoic Trans-Hudson orogeny (ca. 1900-1800 Ma). A number of structurally controlled mesothermal gold deposits occur throughout the region, associated with this shear zone network. The Tartan Lake gold deposit occurs in the Tartan Lake shear zone, at the contact between a layered gabbroic intrusive complex and metavolcanic rocks of the Amisk group (ca. 1875 Ma). Five phases of deformation have been recognised in the Flin Flon region (P1-P5). Mid-greenschist facies peak metamorphic conditions (phase 3) at Tartan Lake are recorded by a mineral assemblage of biotite-actinolite-albite-muscovite-epidote and carbonate in volcaniclastic rocks, along with a well-developed phase 3 schistosity. Early movement of the Tartan Lake shear zone was initiated with phase 3 deformation, during which oblique slip occurred. During phase 4, this shear zone was overprinted by a major regional fold and the shear zone was reactivated by strike-slip movement. Regional phase 3 schistosity is refolded in a series of steeply plunging mesoscopic phase 4 fold closures that were synchronous with the shear zones.