GEOLOGY FOR ENVIRONMENTAL PLANNING IN THE MILTON-ST. ALBANS REGION, VERMONT By DAVID P. STEWART VERMONT GEOLOGICAL SURVEY Charles C. Doll, Stale Geologist c c WATER RESOURCES DEPARTMENT MONTPELIER, VERMONT ENVIRONMENTAL GEOLOGY NO. 5 1971 TABLE OF CONTENTS Page INTRODUCTION 7 SOURCE OF MATERIAL ..................... EXPLANATION OF PLANNING MAPS ............ 12 (;EOLOGIC SETTING ..................... Champlain Lowland .................... 13 (;reen Mountains ..................... 16 Environmental Significance of Structures............... DRAINAGE ........................ 17 BURIED VALLEYS .................... 19 SURFICIAL MATERIAL .................. 21 BEDROCK ....................... 22 Rocks of the Champlain Lowland ............... 22 Rocks of the Green Mountains ................ 24 SURFACE WATER .................... 24 (;ROUND WATER ..................... 5 SOLID WASTE DISPOSAL ................. 31 sEwA(;E DISPOSAL .................... 36 FOUNDATION MATERIAL ................. 38 GEOLOGIC HAZARDS .................... 9 Landslides ....................... 39 Flash Floods ....................... 39 (;EOLOGIC RESOURCES .................. 43 Sand and Gravel ..................... 43 Crushed Stone ...................... 44 Lime and Chemical I'roducts ................. 45 Dimension Stone ..................... 45 Natural (;as ....................... 45 ACKNOWLED(;MENTS ..................... REFERENCES CITED ................... 47 REFERENCES FOR PLANNERS ................ 48 AP1ENDIX A - MAIS SHOwINC; LOCATIONS OF SEISMIC IROFILES. 49 LIST OF ILLUSTRATIONS Page FIGURE 1. Index map showing where environmental geology studies have been corn pleted.............. 6 FIGURE 2. Index map showing the location of quadrangles, townships, cities and villages in the Milton-St. Albans region . . . . 8 FIGURE 3. The Champlain Lowlands and the Islands of Lake Cham- plain. Picture taken looking west from Belvedere Hill one mile east of St. Albans . . . . . . . . . . . . . 9 FIGURE 4. Mt. Mansfieid looking toward the east side of the mountain. Picture taken looking west from Stowe . . . . . . . 9 FIGURE 5. Ski slopes of Madonna Ski Area. Six miles south-southeast ofJeffersonville................. 11 FIGURE 6. A portion of Madonna Village, a development near the foot of the Madonna Ski Area. Four miles south-southeast of Jeffersonville ................. 11 FIGURE 7. Power auger on trailer pulled by a jeep used for percolation tests .................... 12 FIGURE 8. Geomorphic subdivisions, major structures and topographic features of the Milton-St. Albans region . . . . . . 14 FI(;URE 9. Aldis Hill, an outlier of the Hincshurg-Oak Hill thrust. Pic- ture taken looking northwest from Belvedere Hill one and one-half miles southeast of St. Albans . . . . . . . 15 FIGURE 10. Drainage basins of the Milton-St. Albans region . . . . 18 FIGURE 11. Ma1) showing the former buried valleys of the Winooski, Lamoille and Missisquoi rivers . . . . . . . . . . 19 FIGURE 12. Bouldery surface of till on the Champlain Lowland. Fine sediment was removed by wave action. One mile northeast of St. Albans . . . . . . . . . . . . . . . . 20 FIGURE 13. Gravel face of a pit exposing the (ross-section of an esker with well-developed ice-contact structures. One and one- half miles northeast of Enosburg Falls . . . . . . . 21 FIGURE 14. Fractures enlarged by solution weathering of dolomite rock. Exposed in a stone quarry in the village of Milton . . . 22 FI(;URE 15. Weathered slate exposed in an abandoned quarry on North Hero Island.................... FIGURE 16. Enlarged fractures in carbonate rock one mile cast of Highgate Springs . . . . . . . . . . . . . . 26 FIGURE 17. Solution channels in dolomite rock. Exposed in a stone quarry in Winooski . . . . . . . . . . . . . 27 FI(;uRE 18. North-south seismic profile across the Missisquoi River valley at North Enosburg . . . . . . . . . . . 28 FI(;uRE 19. East-west seismic profile across a buried valley immediately east of Highgate Springs . . . . . . . . . . . 28 FIGURE 20. East-west seismic profile across Black Creek valley two and one-half miles south of Sheldon village . . . . . . 28 FIGURE 21. Northeast-southwest seismic profile across the Lamoille River valley three and one-half miles east-northeast of JefTersonville FI(;URE 22. North-south seismic profile across the Lamoille River valley one mile west of Cambridge village . . . . . . . 30 FI(;uRE 23. Northeast-southwest seismic l)rofile across the Browns River valley one mile south of Underhill village . . . . . . 30 FIGURE 24. North-south seismic profile across the Browns River valley one mile east of Underhill village ............ 1 FIGURE 25. Gravel exposed in the Berkshire kame complex, one and one-half miles northwest of Enosburg Falls . . . . . 32 FIGURE 26. Kame and kettle topography of the Berkshire kame com- plex. Picture taken looking east one mile south-southwest of West Berkshire . . . . . . . . . . . . . . 32 FIGURE 27. Lanclfill in gravel of the Buck Hollow kame deposit. Five miles north of Fairfax ............... 3 FIGURE 28. Sand used as a cover for a landfill, one mile west of Highgate Falls .................... 34 FI(;URE 29. Landfill site one mile west of Highgate Center. Sand cover has blown away exposing the refuse . . . . . . . . 35 FIGuRE 30. Material not buried in landfill pushed over the valley wall of a tributary of the Browns River. Two miles south-south- east of Fairfax village . . . . . . . . . . . . . 35 FIGURE 31. The Winooski River valley inundated by flood waters on July 1, 1973. Picture taken looking north from State Route 127 one mile west of Winooski. 40 FIGURE 32. The Winooski River in flood stage on July 1, 1973. Picture taken looking upstream from the bridge at Winooski. .4 I FIGuRE 33. The Winooski River level at normal flow. Same location as figure 32, but taken six weeks after the flood . 41 FIGURE 34. Bottomland along the Lamoille River that was covered with silt and sand by the flooding of the river. Four miles east- northeast of Jeffersonville ............. 4 FIGURE 35. Erosion along the Lamoille River. Across the river from Cambridge village . 42 FIGuRE 36. Quarry in dark colored limestone marble. One and one- half miles southeast of the village of Isle La Motte ..... 45 FI(;uRE 37. Oil-gas drilling rig. Three miles northwest of the city of St. Albans ................... 45 PLATES (In Pocket) PLATE I. Surficial Material of the Milton-St. Albans Region PLATE II. Bedrock of the Milton-St. Albans Region 1LATE III. Ground Water Potential Map of the Milton-St. Albans Region PLATE IV. Solid Waste Disposal Conditions of the Milton-St. Albans Region PLA1E V. Septic Tank Conditions of the Milton-St. Albans Region PLATE VI. General Construction Conditions of the Milton-St. Albans Region 1LATE Vii. Sand and Gravel Reserves of the Milton-St. Albans Region AArr NEwP , GUILDHAL et wos( EE1 () I JOHNSBtJR WTRUY - C o 2 - LE E - BRADFORD ECHESE ETHEL - - Wh,t C- '-'- WHITE RIVER JUNCTION ee 6' EXPLANATION '1Y,0O0STOCK - RUTLAND Barre-Montpelier Region I WINDSOR (Stewart, 1971) Rutland- Brandon Region (Stewart, 1972) Burlington-Midd)ebury Region I (Stewart, 1973) I - Johnson- Hardwick Region ANC EST " BELLOWS (Wright, in press) FALLS / Milton-St. Albans Region U/ (This report) L::. G~ATTLEBOR O Figure 1. Index map showing regions where environmental geology studies have been completed. 6 GEOLOGY FOR ENVIRONMENTAL PLANNING IN THE MILTON-ST. ALBANS REGION, VERMONT By David P. Stewart* INTRODUCTION have geologists on their staffs, and these reports supply the geologic background necessary for ade- The accumulation of geologic data is an essen- quate planning. tial prerequisite to many aspects of environmental In the four-year period that the environmental planning. Geology adds a third dimension to plan- geology program has been in progress, the regions fling inasmuch as it is concerned with the characteris- studied have been selected because of their potential tics of the subsurface soil and rock as well as the ob- growth. The initial study was completed in the Barre- vious features on the surface. All environmental Montpelier region and a report on that investigation problems that involve the movement of water, the was published in 1971. The second survey concerned supply of ground water, the strength of earth ma- the Rutland-Brandon region and the report on that terials, and the reserves of earth resources are related area was published in 1972. In 1973, a report was to the geology of the subsurface. These factors, in published on the Burlington-Middlebury region turn, are controlled by the texture of the rock and (Figure 1). In each of the regions, the field work was soil, the degree of metamorphic changes, the frac- done during the field season of the year preceding tures in the rock, the ability of the materials to hold the publication of the report. The environmental and transmit water, and the plasticity. The avail- geology program was expanded in 1973, and during ability of water and the contamination of water sup- the summer of that year two field parties were work- plies are related to the movement of liquids. The ing in two different regions. Frank M. Wright, III thickness, strength, and stability of surficial materials joined the program and studied the Johnson-Hard- determines their suitability for foundations for heavy wick region and the writer completed the Milton-