Laserfiche WebLink
a <br /> 'i <br /> 44 <br /> 7 <br /> i.� <br /> CHAPTER 3 <br /> HYDROGEOLOGY <br /> 1A <br /> This section presents a description of the hydrogeology at the site based on Brown and <br /> 14 Caldwell Consultant's as well as previous investigations of the site. <br /> Regional Geology <br /> {' Lodi is underlain by three major geological units. In descending stratigraphic order they <br /> i . <br /> are: (1) unconsolidated alluvial sediments, (2)consolidated nonmarine and murine sedimentary <br /> rocks, and (3)metamorphic:and igneous basement rocks, The regional geology was detemzired <br /> - from the California Department of Water Resources Bulletin 118-6 and the State Geoiogical Map, <br /> j Sacramento Quadrangle. <br /> is 5 <br /> 14 <br /> Alluvial deposits of Quaternary-age immediately underlie Lodi. These deposits,which may <br /> be yup to 500 feet in thickrPss, are -trade up of layers of sand, silt, and clay, with interfing,;red <br /> ancient stream channel deposits of sand and gravel. Permeability is variable except in the ancient <br /> buried stream channels,where it is generally high. These unconsolidated deposits contain fresh <br /> a mater. <br /> t� <br /> ;�- Underlying these alluvial deposits are Late Eocene-age through Plio-Pleistocene-age,alluvial <br /> _ and lacustrine deposits up to 1,620 feet in thickness. With the exception of the Eocene-age <br /> formations, these formations and generally freshwater-bearing. U,tderlying the nonmarine <br /> sequence are consolidated marine rocks (silty claystone with thin interbeds of sandstone and <br /> Is <br /> conglomerate) of Cretaceous- and Early Tertiary-age. These water bearing rocks generally do <br /> l <br /> not contain fresh water.' <br /> i <br />