The data on the paleomagnetics of the volcanic rocks provided by Wellensiek et al. [ 1990] (hereinafter referred to as Wellensiek et al.) are welcome contributions to ongoing studies of the tectonic history of Maine and the northern Appalachians. Deficiencies in the presentation of important aspects of the geology of the region and of the particular area of the study by Wellenseik et al. motivate this comment, better to inform readers of the context of the paleomagnetic findings. REGIONAL SETTING 1. The Lunksoos "terrane" (formerly Weeksboro-Lunksoos anticlinorium [Osberg et al., 1985], also Lunksoos anticlinorium [Boone and Boudette, 1989]) is not part of the Kearsarge-Central Maine synclinorium. The latter is a broad Acadian structural feature that preserves a Silurian-Devonian trough. The northwestern boundary of this trough is the hinge zone defined by Moench [Moench and Pankiwskyj, 1988] in the Rangely area, northwestern Maine that may correspond with the deeply buried eastern margin of Grenvillian crust [Stewart, 1989]. This hinge zone is manifested along the SE flank of the Lunksoos anticlinorium by unnamed conglomerate of Silurian age (map unit S g of Neuman [ 1967]). 2. Of the several anticlinoria ("terranes" of Wellensiek et al.) in northern Maine the Lunksoos is Copyright 1991 by the American Geophysical Union. Paper number 91TC00059. 0278-7404/91/91 TC-00059 $02.00 the only one that preserves a non-North American Early Ordovician fauna, the Celtic brachiopod assemblage of the Shin Brook Formation [Neuman, 1984]. The Miramichi anticlinorium that extends across New Brunswick to the east also has Lower Ordovician fossiliferous rocks that contain such a fauna, but none of these is known to occur in Maine in the southwestern end of this anticlinorium. The few identifiable Ordovician shelly fossils elsewhere in northern Maine are all younger than those of the Shin Brook Formation, and they are assemblages of "Scoto-Appalachian" provincial affinities [Neuman, 1984]. 3. The statement that the "Stacyville volcanics" overlie the Shin Brook Formation is incorrect. No such relations are known to exist in the Lunksoos anticlinorium where only undated "metadiabase" overlies the Shin Brook. Such a relationship might be inferred, however, from known or estimated ages within the Lunksoos anticlinorium and from apparently unfaulted sequences of similar rocks of the same age span of the Miramichi anticlinorium in the Hayesville area, New Brunswick [Irrinki, 1980]. 4. The presence of the Katahdin Granite, the largest granitic body in Maine, should have been shown on Figure 1 of Wellensiek et al.. Its eastern margin is as close as 3 km SW of the three sample sites, wmc, wv3, and wv4. GEOLOGIC SETI'ING OF THE "STACYVILLE VOLCANICS" IN THE SHIN POND AREA 1. The source of the map (Figure 1 of Wellensiek et al.) is not attributed; apparently it was taken from an enlargement of a part of the 1985 state bedrock geologic map [Osberg et al., 1985] that was

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