A global plate motion model, named NUVEL-1, which describes current plate motions between 12 rigid plates is described, with special attention given to the method, data, and assumptions used Tectonic implications of the patterns that emerged from the results are discussed It is shown that wide plate boundary zones can form not only within the continental lithosphere but also within the oceanic lithosphere; eg, between the Indian and Australian plates and between the North American and South American plates Results of the model also suggest small but significant diffuse deformation of the oceanic lithosphere, which may be confined to small awkwardly shaped salients of major plates

Current plate motions

SUMMARY 
We determine best-fitting Euler vectors, closure-fitting Euler vectors, and a new global model (NUVEL-1) describing the geologically current motion between 12 assumed-rigid plates by inverting plate motion data we have compiled, critically analysed, and tested for self-consistency. We treat Arabia, India and Australia, and North America and South America as distinct plates, but combine Nubia and Somalia into a single African plate because motion between them could not be reliably resolved. The 1122 data from 22 plate boundaries inverted to obtain NUVEL-1 consist of 277 spreading rates, 121 transform fault azimuths, and 724 earthquake slip vectors. We determined all rates over a uniform time interval of 3.0m.y., corresponding to the centre of the anomaly 2A sequence, by comparing synthetic magnetic anomalies with observed profiles. The model fits the data well. Unlike prior global plate motion models, which systematically misfit some spreading rates in the Indian Ocean by 8–12mm yr−1, the systematic misfits by NUVEL-1 nowhere exceed ∼3 mm yr−1. The model differs significantly from prior global plate motion models. For the 30 pairs of plates sharing a common boundary, 29 of 30 P071, and 25 of 30 RM2 Euler vectors lie outside the 99 per cent confidence limits of NUVEL-1. Differences are large in the Indian Ocean where NUVEL-1 plate motion data and plate geometry differ from those used in prior studies and in the Pacific Ocean where NUVEL-1 rates are systematically 5–20 mm yr−1 slower than those of prior models. The strikes of transform faults mapped with GLORIA and Seabeam along the Mid-Atlantic Ridge greatly improve the accuracy of estimates of the direction of plate motion. These data give Euler vectors differing significantly from those of prior studies, show that motion about the Azores triple junction is consistent with plate circuit closure, and better resolve motion between North America and South America. Motion of the Caribbean plate relative to North or South America is about 7 mm yr−1 slower than in prior global models. Trench slip vectors tend to be systematically misfit wherever convergence is oblique, and best-fitting poles determined only from trench slip vectors differ significantly from their corresponding closure-fitting Euler vectors. The direction of slip in trench earthquakes tends to be between the direction of plate motion and the normal to the trench strike. Part of this bias may be due to the neglect of lateral heterogeneities of seismic velocities caused by cold subducting slabs, but the larger part is likely caused by independent motion of fore-arc crust and lithosphere relative to the overriding plate.

/pdf/global-continental-and-ocean-basin-reconstructions-since-200-huopwd2ldv.pdf

Global continental and ocean basin reconstructions since 200 Ma

We have constructed a magnetic polarity time scale for the Late Cretaceous and Cenozoic based on an analysis of marine magnetic profiles from the world's ocean basins. This is the first time, since Heirtzler et al. (1968) published their time scale, that the relative widths of the magnetic polarity intervals for the entire Late Cretaceous and Cenozoic have been systematically determined from magnetic profiles. A composite geomagnetic polarity sequence was derived based primarily on data from the South Atlantic. Anomaly spacings in the South Atlantic were constrained by a combination of finite rotation poles and averages of stacked profiles. Fine-scale information was derived from magnetic profiles on faster spreading ridges in the Pacific and Indian Oceans and inserted into the South Ariantic sequence. Based on the assumption that spreading rates in the South Atlantic were smoothly varying but not necessarily constant, a time scale was generated by using a spline function to fit a set of nine age calibration points

/pdf/a-new-geomagnetic-polarity-time-scale-for-the-late-47c9jfk0ho.pdf

A new geomagnetic polarity time scale for the Late Cretaceous and Cenozoic

Geochronology of the Phanerozoic granitoids in northeastern China

SUMMARY This paper presents new data from palaeomagnetic investigations on the Upper Palaeozoic and Mesozoic geological units from the Siberian platform and the Mongol–Okhotsk suture zone. Within the southern portion of the Mongol–Okhotsk suture we collected palaeomagnetic samples from the Late Permian Belektuy formation (Borzya region; 50.7uN, 116.9uE) and the Middle–Late Jurassic Shadaron formation (Unda-Daya; 51.5uN, 117.5uE). We sampled the Late Permian Alentuy formation (Khilok region; 50.8uN, 107.2uE), the Early to Middle Jurassic Irkutsk sedimentary basin (ISB; 52.0uN, 104.0uE), the Late Jurassic Badin formation (Mogzon region; 51.8uN, 112.0uE), and the Early Cretaceous Gusinoozesk formation (Gusinoe Lake region; 51.2uN, 106.5uE) additionally in the northern region of the Mongol–Okhotsk suture. Apart from the results of the ISB and Gusinoozersk formations, which show very large ellipses of confidence and might be the present-day geomagnetic field overprint, our results allow us to constrain the evolution of the Mongol–Okhotsk Ocean palaeomagnetically from the Late Permian to the Middle–Late Jurassic. They confirm that this large Permian ocean closed during the Jurassic, ending up in the late Jurassic or the beginning of the Cretaceous in the eastern end of the suture zone, as suspected on geological grounds. However, although geological data suggest a Middle Jurassic closure of the Mongol–Okhotsk Ocean in the west Trans-Baikal region, our data show evidence of a still large palaeolatitude difference between the Amuria and Siberia blocks. This is interpreted as a result of the quite fast closure of the ocean after the Middle Jurassic. Finally, our new palaeomagnetic results exhibit very large tectonic rotations around local vertical axes, which we interpret as probably arising both from collision processes and from a left-lateral shear movement along the suture zone, due to the eastward extrusion of Mongolia under the effect of the collision of India into Asia.

/pdf/evolution-of-the-mongol-okhotsk-ocean-as-constrained-by-new-1g4a909nzn.pdf

Evolution of the Mongol-Okhotsk Ocean as constrained by new palaeomagnetic data from the Mongol-Okhotsk suture zone, Siberia

Oceanic crust between 38°S and 65°S along the Pacific-Antarctic ridge records a complete history of Neogene Pacific-Antarctic motion. We have modeled magnetic stages corresponding to portions of isochrons 1, 2, 2A, 3, 3A, 4, and 5 from 17 high-quality marine magnetic traverses of the ridge to determine the Neogene finite rotation poles for this plate pair. We chose to model velocities over time intervals of about 0.5 m.y. because this greatly increased the number of estimates of Pacific-Antarctic plate velocity. Our analysis shows that a change in Pacific-Antarctic relative motion occurred between chron 2A, 3.40 Ma, and the beginning of chron 3 time, 3.86 Ma. We used 203 estimates of Pacific-Antarctic spreading velocity to calculate a 0–3.4 Ma and 3.86–10.3 Ma Euler pole. Combined with tracks of seamounts that record the passage of the Pacific plate over mantle plumes our data show that this change in relative motion corresponds to a change in the absolute motion of the Pacific plate with respect to the hotspot frame of reference. Using these Euler poles to calculate Pacific-Antarctic-Africa-North America circuit Euler poles show that this recent change in Pacific plate absolute motion corresponds to a change from strike-slip to transpressive motion along the coastal California Pacific-North America plate boundary. Interestingly, this age of increased tectonism agrees in time with deformation in New Zealand and northern Japan.

Late Neogene motion of the Pacific plate

The Mendocino triple junction area of northern California is underlain by the Coastal belt of the Franciscan complex, flanked on the east by the Central and Eastern belts of the Franciscan Complex. The coastal belt is further divided into three tectonostratigraphic terranes. Upper Cretaceous through middle Miocene rocks included in these terranes were accreted to the North American plate margin partly during normal convergence with the Farallon plate between 49 and 25 Ma at poleward rates of 2 to 5cm /yr, and partly during translation with the Pacific plate between 14 and 2 Ma at poleward rates of 3 to 6cm/yr. The evolution of the triple junction is discussed. -from Authors

/pdf/plate-motions-recorded-in-tectonostratigraphic-terranes-of-2gb41g0tq5.pdf

Plate motions recorded in tectonostratigraphic terranes of the Franciscan complex and evolution of the Mendocino triple junction, northwestern California

In this paper a new set of finite rotations describing the relative motion of the Pacific and North America plates during the last 10 m.y., incorporating recently published studies of the Pacific‐Antarctic, Antarctic‐Africa, and Africa‐North America plate boundaries is presented. These finite rotations show that changes have occurred in Pacific‐western North America motion at 2.48 Ma and between 3.40 and 3.9 Ma, resulting in increased compression along the Pacific‐North America plate boundary. The most significant change in relative motion was of the latter age. During this change the predicted motion of the Pacific plate along the California coast changes from transform to transpressive, due to a clockwise rotation of the relative convergence vector by 12°. This timing of the onset of transpression agrees well with a variety of geologic data along the California plate boundary, including the onset of compressive deformation in onshore and offshore sedimentary basins, formation of reverse faults and anticlines (which are parallel to strike‐slip faults of the previous, more westerly directed azimuth of relative motion), a change in the orientation of the San Andreas fault, and formation of a set of new, more northerly trending strike‐slip faults. In this model this change in relative motion is caused by a change in the absolute motion of the Pacific plate, due to the detachment of a slab beneath the Fiji Basin between 3.4 and 3.9 Ma. The detachment of this slab and the resultant change in overall Pacific plate torque resulted in a noncollisional “orogeny” along the California plate boundary. This study shows that minor adjustments in the motion of large oceanic plates, such as the Pacific plate, can have profound consequences on the preserved geologic record. Copyright 1991 by the American Geophysical Union.

Late Neogene relative motions of the Pacific and North America Plates

https://www.ualberta.ca/~vadim/Publications-Kravchinsky_files/1997-Xu%20Harbert%20Dril%20Kravchinsky.pdf

New paleomagnetic data from the Mongol–Okhotsk collision zone, Chita region, south-central Russia: implications for Paleozoic paleogeography of the Mongol–Okhotsk ocean

William Harbert

Papers

Evolution of the Mongol-Okhotsk Ocean as constrained by new palaeomagnetic data from the Mongol-Okhotsk suture zone, Siberia

Late Neogene motion of the Pacific plate

Plate motions recorded in tectonostratigraphic terranes of the Franciscan complex and evolution of the Mendocino triple junction, northwestern California

Late Neogene relative motions of the Pacific and North America Plates

New paleomagnetic data from the Mongol–Okhotsk collision zone, Chita region, south-central Russia: implications for Paleozoic paleogeography of the Mongol–Okhotsk ocean