NEAR-LAURENTIAN PALEOGEOGRAPHY OF THE LAWRENCE HEAD VOLCANICS OF CENTRAL NEWFOUNDLAND, NORTHERN APPALACHIANS

Paleomagnetic analyses were completed on two volcanic units of the Exp loits Group in Newfoundland's Central Mobile Belt, which are part of a n Ordovician are-back-are system. The Tea Arm Volcanics display scatte red and unstable characteristic directions that cannot be interpreted. However, stable end-points in six sites supported by great-circle ana lysis of seven sites in the mid-Arenigian to LIanvirnian Lawrence Head Volcanics yield a tilt- and strike-corrected characteristic direction of D = 56 degrees, I = 23 degrees, (alpha(95) = 19 degrees, k = 14, N = 6). The magnetization is carried by magnetite and passes a hit test . The corresponding paleolatitude of 12 degrees +/- 10 degrees is inte rpreted as southerly, and is similar to the paleolatitude of 11 degree s +/- 4 degrees for are volcanics of the nearby Moreton's Harbour Grou p. However, this near-laurentian paleolatitude is distinctly different from the paleolatitude of 31 degrees +/- 8 degrees reported for the R obert's Arm-(Cottrell's Cove)-Chanceport-Summerford volcanic terrane. The low paleolatitude of the Lawrence Head Volcanics supports the loca tion of a major Ordovician subduction system near the Laurentian margi n of Iapetus, whereas the present-day juxtaposition of latitudinally d istinct elements in the area represents a complex accretionary history involving Early Silurian or older thrusting and younger strike-slip f aulting of several Iapetan island-are terranes to Laurentia.