Laserfiche WebLink
August I 8, 2004 <br />Mr. Jim Thomas <br />ISclvcdcrc Lols 32 anJ 33 <br />I.&A .lob No. 4AOFSR <br />Pagc 3 <br />residences are �u be construcicd on Ihe caslern to souihcastern, upland shelf arcas of the lols. The <br />upl.md ridge shelf area has alrcady hecn cleaned and grubbed and the stcep slope flanking the <br />ridgc lo tlie easl is co�ered wiU� very dense brush and shrubs and dottcd by deciduous anJ <br />cvcrgrccn Irccs. <br />CGOLOCIC SCT'I'ING <br />l'he Preliminarv Geulo�ic Mao of the Muk�!tco and Gverett Uuadran�les Snohomish Countv, <br />Washineton, by Mackey Smith, published by U. S. Geological Survey in 1976, ti'as referenced <br />for �hc gcologic and soil conditions a� Ihc lo�s. Accor�ing �o this publication, Ihc surficiai soil <br />unils at and in thc viciniry oC Ihe lots are mapped as Vashon Till (Q��) underlain hy Fsperancr <br />Sand (Q�), which is in turn undcrlain by Whidbe} I'onnation (Q�,�j. <br />Thc gcology of the Puget Sound Lo��l�nd has bcen modi��ed hy thc a�1.,inrc :�nd retrcat ul' <br />sevcral glacicrs in thc past and subsequcnt dcposits and erosion. Thc lates� glacier advanced �o <br />thc Pugcl Sound Lowland is rcfcrrcd to as thc Vashon Stadc of thc Frascr Glaciation, which has <br />uccurrcd during thc I:dcr st:iges of Ihc Plcistoccnc fipoch and relrcated f�om dte region somc <br />14,500 ycars a�;u. <br />I he Vashon "I ill was dcpositcd direclly hy glacial ice Jurin� the most recent glacial perioJ as il <br />;iJvanced over an crodcd. irrcgular surface ol olJer fonnalions and sediments. Il is a very dense <br />mixlurc of unsurtcd clay, silt, sand, gravcl, and sc�ttcred cobbles and boulders, o(ien referred to <br />as "�inrd pan", l he till soils o�cr dic tup two tu fuur feel are normally wca�hered to a medium <br />dcnsc slatc, and iti modcratcly permcablc and compressiblc. Thc underlying fresh till is vcry <br />dcnse aud is p�.��u��iiy ��ni��rvious to stormwater inliltr.uion. The fresh lill has lhe slrenglh of <br />lo��-�radc cnncrete and can stand in a stecp natural or cut slopc for a long periud. If remains <br />LIU & AStiOCIATES, INC. <br />, �/,�;� �> � <br />L___ <br />