HYDROGRAPHY AND HOLOCENE SEDIMENTATION OF THE MERRIMACK RIVER ESTUARY, MASSACHUSETTS,
Abstract
The Merrimack River estuary, situated on glaciated terrain along the coast of northeastern Massachusetts, is representative of the Type B estuary of Pritchard (1955). A sharp, slightly tilted boundary between salt water to the north and fresh water to the south develops during periods of normal and high runoffs. At low runoff the stratification disappears. The distribution of bottom sediments is closely related to the hydraulic circulation pattern, tidal current velocities, bottom topography, and sediment source areas. Three types of sand are present in the estuary. A yellow-orange feldspathic suite occupies the main channel. A gray feldspathic suite underlies the marshes of the lower estuary. A third sand type, which is predominantly quartz (86%) with subequal amounts of gray and yellow-orange feldspar (5%), is common in the central part of the main channel and in some tidal channels. The stratigraphy and geometry of the deposits of the fringing salt marshes document a gradual rise in sea level and infilling of an original open bay environment behind the barrier islands accompanying marine transgression since late Pleistocene. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1970
- Accession Number
- AD0709144
Entities
People
- Allan D. Hartwell
Organizations
- University of Massachusetts Amherst