USGS Science⌕ Search

Geology topics

Norman L. Hatch

Publications and source records attributed to Norman L. Hatch.

17 recordsLinked to original sources
USGS1984

Evidence for tectonic emplacement of ultramafic and associated rocks in the pre-Silurian eugeoclinal belt of western New England: Vestiges of an ancient accretionary wedge

In northern Vermont, detailed 1:10,000 mapping of the Hazens Notch, Ottauquechee, Stowe, and Moretown formations in the 60 km 2 Jay area has shown that metasedimentary rocks and serpentinites are highly faulted to produce a tectonic stratigraphy in which serpentinites and talc-carbonate rocks occur as slivers along faults that separate contrasting lithic assemblages. Remnants of the ophiolite sequences of Quebec. In western Massachusetts, the ultramafic-bearing section of the Rowe Schist and the western part of the Moretown Formation are largely equivalent to the rocks in northern Vermont. Mapping at 1:24,000 scale and compilation work for the new bedrock map of Massachusetts have shown that the Rowe Schist consists of numerous lenses of greenschist, carbonaceous schist, gray schist, amphibolite, and serpentinite. Although the geometric arrangement of the lenses and serpentinites is strikingly similar to that seen in the Jay area, higher grade Taconian and Acadian metamorphism has partially obscured the fault fabrics seen in Vermont.

Massachusetts, Vermont↗
USGS1984

Lithotectonic assemblages as portrayed on the new bedrock geologic map of Massachusetts.

Scale of 1:250,000. The map units are grouped into eight lithotectonic packages. Five "zones" of older rocks that cover the whole state are, from west to east, the Taconic-Berkshire, Rowe-Hawley, Bronson Hill, Nashoba, and Milford-Dedham. In central and western Massachusetts, these zones are overlain by the Connecticut Valley and Merrimack "belts" of Silurian-Devonian, and local Carboniferous, strata; the two belts are distinguished from each other on the basis of the lithofacies of the Silurian strata. In eastern Massachusetts, the Milford-Dedham Zone also includes Silurian-Devonian, Carboniferous, Mesozoic, and Tertiary strata. A Mesozoic "basin" is separately identified in the Connecticut Valley region

Massachusetts↗