干旱区生态环境知识资源中心(Arid): Quantifying rates of rifting while drifting in the southern Gulf of California: The role of the southern Baja California microplate and its eastern boundary zone

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DOI	10.1130/L1132.1
	Quantifying rates of rifting while drifting in the southern Gulf of California: The role of the southern Baja California microplate and its eastern boundary zone
	Umhoefer, Paul J.1; Plattner, C.2; Malservisi, R.3
通讯作者	Umhoefer, Paul J.
来源期刊	LITHOSPHERE
ISSN	1941-8264
EISSN	1947-4253
出版年	2020
卷号	12 期号:1 页码:122-132
英文摘要	The southern Baja California (Mexico) microplate has been rapidly moving away from the North America plate since ca. 12 Ma. This relative motion toward the northwest developed an oblique-divergent plate boundary that formed the Gulf of California. The rift-drift hypothesis postulates that when a continent ruptures and seafloor spreading commences, rifting on the plate margins ceases, and the margins start to drift, subside, and accumulate postrift sediments, eventually becoming a passive margin. In contrast to this hypothesis, the southern part of the Baja California microplate (BCM), and in particular its actively deforming eastern boundary zone, has continued significant rifting for millions of years after seafloor spreading initiated within the southern Gulf of California at 6-2.5 Ma. This is a process we call rifting-while-drifting Global positioning system (GPS)-based data collected from 1998 to 2011 show relative motion across the eastern boundary zone up to -2-3.2 mm/yr with respect to a stable BCM. Furthermore, the velocity directions are compatible with normal faulting across the eastern boundary zone nearly perpendicular to the trend of the plate boundary at the latitude of La Paz and therefore a highly strain partitioned domain. North of 25 degrees N latitude up to the Loreto area, there is a domain with no strain partitioning, and northwest-directed transtensional deformation dominates. From long-term geologic and paleoseismology studies, late Quaternary faulting rates are equal to or less than the GPS-derived rates, while geologic rates older than 1-2 Ma are commonly much higher. We suggest that the rifting-while-drifting process may be caused by the large topographic relief across the BCM margin, which created a significant gradient in gravitational potential energy that helps in driving continued relatively slow faulting. The relief was inherited from the much faster faulting of the BCM eastern boundary zone before plate motions largely localized along the modern transform-spreading centers in the axis of the Gulf of California. The low sediment flux from the small drainages and arid climate on the southern Baja California Peninsula result in the maintenance of underfilled to starved basins, and the relatively slow late Quaternary active faulting promotes continued topographic relief over millions of years.
类型	Article
语种	英语
国家	USA ; Germany
开放获取类型	Green Submitted, gold
收录类别	SCI-E
WOS记录号	WOS:000517774400007
WOS关键词	OCEAN-CONTINENT TRANSITION ; LOS-CABOS REGION ; PACIFIC PLATE ; MIDDLE MIOCENE ; SUR ; MARGIN ; MOTION ; MEXICO ; FAULT ; TECTONICS
WOS类目	Geochemistry & Geophysics ; Geology
WOS研究方向	Geochemistry & Geophysics ; Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/315150
作者单位	1.No Arizona Univ, Sch Earth & Sustainabil, 624 S Knoles Dr,Ashurst Bldg,Room A108, Flagstaff, AZ 86011 USA; 2.Ludwig Maximilians Univ Munchen, Dept Umwelt & Geowissensch, Sekt Geol, Luisenstr 37, D-80333 Munich, Germany; 3.Univ S Florida, Sch Geosci, 4202 E Fowler Ave,NES107, Tampa, FL 33620 USA
推荐引用方式 GB/T 7714	Umhoefer, Paul J.,Plattner, C.,Malservisi, R.. Quantifying rates of rifting while drifting in the southern Gulf of California: The role of the southern Baja California microplate and its eastern boundary zone[J],2020,12(1):122-132.
APA	Umhoefer, Paul J.,Plattner, C.,&Malservisi, R..(2020).Quantifying rates of rifting while drifting in the southern Gulf of California: The role of the southern Baja California microplate and its eastern boundary zone.LITHOSPHERE,12(1),122-132.
MLA	Umhoefer, Paul J.,et al."Quantifying rates of rifting while drifting in the southern Gulf of California: The role of the southern Baja California microplate and its eastern boundary zone".LITHOSPHERE 12.1(2020):122-132.