Full Title: Mesozoic igneous rocks of northern New England and adjacent Quebec
Compiler: J. Gregory McHone
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One black and white sheet, 35" x 30", scale 1:690,000. From text: The accompanying map shows locations, ages, and major rock types of Mesozoic intrusions in Vermont, New Hampshire, western Maine, and adjacent areas of Massachusetts, New York, and Quebec. Forty-five plutons and approximately 1,200 dikes are shown; discussions and analyses presented by McHone (1978) and McHone and Butler (1984) summarize much of the related geology. Sources listed in the bibliography should be consulted for details on the individual intrusions and their surroundings. Field work and the compilation of the source bibliography were carried out between 1970 and 1983. The work is not complete; the more than 2,500 dikes mapped in the region are estimated to be only 10% to 20% of those exposed, and new exposures are constantly being made from construction activities. In addition, it is possible that small plutons could have been missed or gone unrecognized, and geologic maps of the larger complexes are still being revised. The scale of the map does not allow all dikes (many outcrops contain several) and details of plutonic complexes to be shown. Radiometric analyses continue and are much needed to better understand patterns of magmatic activity in the region. The purpose of the map and the accompanying summary are (1) to show the need for and be the basis of future work; (2) to express patterns of magmatism through time and space in New England, as now known; and (3) to provide information pertinent to tectonic and petrologic models of intraplate magmatism.
Published: 4/01/1984
Pages: 5 plus 1 sheet
Product Category: Maps and Charts