Edward A. Mankinen 1978 <p>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.</p> application/pdf en U.S. Geological Survey Paleomagnetic evidence for a Late Cretaceous deformation of the Great Valley Sequence, Sacramento Valley, California article