Paleomagnetic evidence for a Late Cretaceous deformation of the Great Valley Sequence, Sacramento Valley, California

Paleomagnetic samples from five localities within the Great Valley sequence range in age from Late Jurassic to Late Cretaceous. All samples possess normal polarity, and alternating-field demagnetization experiments show that the remanence was acquired after the sequence was folded. A mean paleomagnetic pole position determined from 17 demagnetized samples is located at 72° N., 181° E., with the radius of the 95-percent circle of confidence equal to 5.4°. This pole position agrees very well with known Cretaceous poles from North America, a fact indicating that the deformation and remagnetization of the sequence must have occurred during the Late Cretaceous.