story of the OWL starts. Other evidence suggests a similar plate reorganization around 80 Ma, possibly connected with the start of the Laramide orogeny. claimed at least five "major chaotic tectonic events since the Triassic". Each of these events is a possible candidate for creating some condition or structure that affected the OWL or ur-OWL, but knowledge of what these events were or their effects is itself still chaotic. Complicating the geology is a stream of terranes – crustal blocks – that have been streaming north along the continental margin for over 120 Ma (and probably much, much earlier), what has recently been called the North Pacific Rim orogenic Stream (NPRS). However, these terranes may be incidental to the OWL, as there are suggestions that local tectonic structures may be substantially affected by deeper and much older (e.g., Precambrian) basement rock, and even lithospheric mantle structures. Subduction of the Farallon and Kula Plates Roughly 205 million years ago (during the Jurassic period) the Pangaea supercontinent began to break up as a rift separated the North American Plate from what is now Europe, and pushed it west against the Farallon Plate. During the subsequent Cretaceous Period (144 to 66 Ma ago) the entire Pacific coast of North America, from Alaska to Central America, was a subduction zone. The Farallon plate is notable for having been very large, and for subducting nearly horizontally under much of the United States and Mexico; it is likely connected with the Laramide Orogeny. About 85 Ma ago the part of the Farallon plate from approximately California to the Gulf of Alaska separated to form the Kula Plate. The period 48–50 Ma (mid-Eocene) is especially interesting as this is when the subducted Kula—Farallon spreading ridge passed below what is now the OWL. This also marks the onset of the Oregon rotation, possibly with rifting along the OWL, and the initiation of the Queen Charlotte and Straight Creek Faults. The timing seems significant, but how all of these might be connected is unknown. Around 30 Ma ago part of the spreading center between the Farallon Plate and Pacific Plate was subducted under California, putting the Pacific plate into direct contact with the North American plate and creating the San Andreas Fault. The remainder of the Farallon Plate split, with the part to the north becoming the Juan de Fuca Plate; parts of this subsequently broke off to form