DOI: 10.1016/j.tecto.2021.228872
论文题名: Paleomagnetic results from Upper Triassic and Middle Jurassic strata of east-central New Mexico, and implication for North American apparent polar wander path
作者: Mirzaei M. ; Housen B.A. ; Burmester R.F. ; Foreman B.Z.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 811 语种: 英语
中文关键词: East-central New Mexico
; Elongation/Inclination
; Inclination error
; North American mid-Jurassic Apparent Polar Wander Path
; Paleomagnetism
; Summerville Formation
英文关键词: Geomagnetism
; Hematite
; Igneous rocks
; Magnetization reversal
; Sedimentology
; High Latitudes
; Inclination errors
; Middle Jurassic
; Morrison formations
; Paleomagnetic poles
; Sedimentary units
; True Polar Wander
; Upper Triassic
; Sedimentary rocks
; apparent polar wander path
; demagnetization
; error analysis
; error correction
; igneous rock
; Jurassic
; magnetization
; paleomagnetism
; polar wandering
; Triassic
; New Mexico
; United States
英文摘要: Two apparent polar wander (APWP) paths for North America (NA) diverge during the Jurassic. The path based on paleomagnetic results from igneous rocks of eastern NA, well-dated Ontario kimberlites, and carbonates and radiolarites of Adria (northern Italy - transformed to NA coordinates) has a large gap at high latitude, which could document rapid plate motion or True Polar Wander. The APWP from coeval NA sedimentary rocks define a lower-latitude, more continuous path. The discrepancy between the two paths has been attributed to inclination error (IE) from deposition and compaction of the sediments. New paleomagnetic results from Upper Triassic (Garita Creek, Trujillo, and Redonda Formations) and Middle Jurassic (Entrada, Summerville, and Lower Morrison Formations) sedimentary units of east-central New Mexico have positive reversal and fold tests, which indicate their magnetization, mostly carried by detrital hematite, is primary. Interpretation of noisy and non-linear demagnetization paths was facilitated by a smoothing scheme, which did not bias the mean directions. Using sample-level directions from line fits, IE was estimated ~20° for the Jurassic units, but is negligible for the Triassic units because mean directions are horizontal. Mean paleomagnetic poles for the ~223 Ma (Garita Creek and Trujillo) and ~214 Ma Redonda Formations are 55.7°N/78.7°E/A95 = 3.2° and 59.7°N/81.0°E/A95 = 4.0°; those for the ~163 Ma Summerville and ~155 Ma Morrison Formations are 59.3°N/138.1°E/A95 = 6.5° and 48.7°N/151.8°E/A95 = 7.8°. Simulated ~163 Ma paleomagnetic poles based on Summerville results and a wide range of IE show that no amount of IE correction to the Summerville directions would produce poles consistent with the high-latitude Jurassic APWP. Furthermore, paleomagnetic poles for Trujillo, Redonda, Summerville, and Lower Morrison Formations of east-central New Mexico, even with IE-correction, streak approximately along the 60° parallel (present coordinates) for most of late Triassic and Jurassic, which validates the lower-latitude APWP. Another explanation for the APWP discrepancy is required. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170863
Appears in Collections: 气候变化与战略
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作者单位: Western Washington University, Geology Department, Building: ES 240, 516 High Street, Bellingham, WA 98225-9160, United States
Recommended Citation:
Mirzaei M.,Housen B.A.,Burmester R.F.,et al. Paleomagnetic results from Upper Triassic and Middle Jurassic strata of east-central New Mexico, and implication for North American apparent polar wander path[J]. Tectonophysics,2021-01-01,811