Lissie Formation (TXQl;0)

State	Texas
Name	Lissie Formation
Geologic age	Phanerozoic \| Cenozoic \| Quaternary \| Pleistocene-Middle
Original map label	Ql
Comments	Sand, silt, clay, and minor amount of gravel. Iron oxide and iron-manganese nodules common in zone of weathering; locally calcareous. Surface fairly flat and featureless except for many shallow depressions and pimple mounds. Moore and Wermund (1993a) mapped three units--(1) alluvium undifferentiated as to texture and origin--includes meander belt, levee, crevasse splay, and distributary sand, and flood-basin mud deposits, about 60 m thick, (2) fine-grained channel facies (alluvial sand, silt, and clay) about 10-25 m thick, thicker seward, and (3) fine-grained overbank facies (alluvial silt and clay) about 55-65 m thick, thicker seaward. Together, these deposits form a deltaic plain that parallels the Gulf Coast. Unit contains Pleistocene vertebrate fauna, dips seaward beneath the Beaumont Fm. and disconformably overlies deposits of the Pliocene and early Pleistocene Willis Formation. The deltaic plain is entrenched as much as 7 m by streams. In Hidalgo County (southernmost part of Texas) the unit underlies a semiarid plain, widely irrigated and cultivated. Unit is locally veneered with thin, discontinuous stabilized eolian sand.
Primary rock type	sand
Secondary rock type	silt
Other rock types	clay or mud
Lithologic constituents	Major Unconsolidated > Fine-detrital > Clay (Bed) Unconsolidated > Coarse-detrital > Sand (Bed) Unconsolidated > Fine-detrital > Silt (Bed)
Map references	Bureau of Economic Geology, 1992, Geologic Map of Texas: University of Texas at Austin, Virgil E. Barnes, project supervisor, Hartmann, B.M. and Scranton, D.F., cartography, scale 1:500,000
Unit references	Bureau of Economic Geology, 1975, Corpus Christi Sheet, Geologic Atlas of Texas, Bureau of Economic Geology, University of Texas at Austin, scale 1:250,000. Moore, D.W. and Wermund, E.G., Jr., 1993a, Quaternary geologic map of the Austin 4 x 6 degree quadrangle, United States: U.S. Geological Survey Miscellaneous Investigations Series Map I-1420 (NH-14), scale 1:1,000,000. [http://pubs.er.usgs.gov/publication/i1420(NH14)] Moore, D.W. and Wermund, E.G., Jr., 1993b, Quaternary geologic map of the Monterrey 4 x 6 degree quadrangle, United States: U.S. Geological Survey Miscellaneous Investigations Series Map I-1420 (NG-14), scale 1:1,000,000. [http://pubs.er.usgs.gov/publication/i1420(NG14)] Bureau of Economic Geology, 1974, Seguin Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000. Bureau of Economic Geology, 1976, Crystal City-Eagle Pass Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000. Bureau of Economic Geology, 1975, Beeville-Bay City Sheet, Geologic Atlas of Texas, Bureau of Economic Geology, University of Texas at Austin, scale 1:250,000. Bureau of Economic Geology, 1982, Houston Sheet, Geologic Atlas of Texas, Bureau of Economic Geology, University of Texas at Austin, scale 1:250,000.
Geographic coverage	Austin - Bee - Calhoun - Colorado - DeWitt - Duval - Fort Bend - Goliad - Grimes - Hardin - Harris - Hidalgo - Jackson - Jasper - Jim Wells - Lavaca - Liberty - Live Oak - Montgomery - Newton - Nueces - Polk - Refugio - San Jacinto - San Patricio - Tyler - Victoria - Waller - Washington - Wharton - Willacy