Vol. 13 No. 4 (1973)
Articles

SUBDUCTION ZONE BETWEEN THE PALEO-AMERICAN AND THE PALEO-AFRICAN PLATES IN NEW ENGLAND

JAMES W. SKEHAN
Weston Observatory, Boston College, Weston, Massachussetts (USA).
S. J.
Weston Observatory, Boston College, Weston, Massachussetts (USA).

Published 1973-10-01

How to Cite

SKEHAN, J. W., & J., S. (1973). SUBDUCTION ZONE BETWEEN THE PALEO-AMERICAN AND THE PALEO-AFRICAN PLATES IN NEW ENGLAND. Geofísica Internacional, 13(4), 291-308. https://doi.org/10.22201/igeof.00167169p.1973.13.4.1142

Abstract

Cambrian and Tremadocian faunas of the Acado-Baltic Province have remarkable simiralities on both sides of the Atlantic (Fig. 1). Lower and Middle Cambrian representatives of this province are present in eastern Massachussetts, whereas Pacific Province faunas are present in nearby western New England and eastern New York. The Boston Border Fault and its presumed continuation to the south marks the western margin of the palco-African Plate which contains the Acado-Baltic faunal localities (Fig. 2). Inmmediately west of the Acado-Baltic localities in Massachussetts is a sequence of rocks interpreted as an ophiolite suite (Fig. 3, 4 and 5), marking a subduction zone whose western margin is marked by the Clinton-Newbury Fault Zone (Fig. 3). The trace of this fault is marked by the most conspicuous magnetic lineament in southeastem. New England (Fig. 6) and is interpreted as the eastern margin of the Paleo-American Plate. The Marlboro and Nashoba Formations and younger Unnamed Formations (Fig. 3 and 4) whose protoliths consist of sea floor metavolcanics and metasediements of the opgiolite suite, represent ensimatic crust, squeezed and intensely deformed between the two paleo-plates. Thus a collision boundary between two continental plates (Fig. 7) is hypothesized for the northern Appalachians. I infer that plate tectonic mechanisms have been operative since at least the end of Precambrian time.