气候变化领域集成服务门户(CCPortal): Early Neogene unroofing of the Sierra Nevada de Santa Marta, as determined from detrital geothermochronology and the petrology of clastic basin sediments

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DOI	10.1130/B31676.1
	Early Neogene unroofing of the Sierra Nevada de Santa Marta, as determined from detrital geothermochronology and the petrology of clastic basin sediments
	Piraquive A.; Pinzón E.; Kammer A.; Bernet M.; von Quadt A.
发表日期	2018
ISSN	167606
起始页码	355
结束页码	380
卷号	130 期号:2021-03-04
英文摘要	We used geothermochronologic data from sedimentary rocks, coupled with stratigraphic analyses, to unravel the late Paleogene to early Neogene exhumation of the Sierra Nevada de Santa Marta massif. This fault-bounded triangular northernmost promontory of the Northern Andes exposes Precambrian to Paleozoic metamorphic rocks and a Triassic to Jurassic magmatic arc. We examined the Neogene basin fills of two marginal basins, a western one located along the Santa Marta-Bucaramanga fault, and a northern one occupying the southern hanging-wall block of the Oca fault. The western sequence consists of ~1200-m-thick conglomeratic gravity deposits that define a progradational Gilbert-type delta emanating from a scarp coinciding with the present Santa Marta-Bucaramanga fault. By its stratigraphic and structural position, this sequence is similar to the northern sequence, which reveals a retrogradational stacking pattern. In order to reconcile these different architectural styles, we propose a regional-scale tilting of the Sierra Nevada de Santa Marta massif toward the NE during the late Paleogene-early Neogene. This model presumes a concomitant evolution of the two sedimentary sequences. Provenance analyses performed on representative units of these sedimentary sections yielded U-Pb age spectra of zircons that correlate with known age data of the underlying basement. Particularly, they lack pre-Grenvillian and Ordovician signals common to Neogene sediments of the wider Miocene Magdalena basin. These marginal basins thus evolved disconnected from the trunk system of the proto-Magdalena River, and they record an initial stage of Oligocene-Miocene segmentation of the South American plate margin. These new findings help to better constrain the paleogeographic setting of the Sierra Nevada de Santa Marta massif and its marginal basins for the late Oligocene-early Neogene during initial breakup of the Caribbean margin. Their sedimentary record depicts an early stage of fault-controlled subsidence of the western margin and a presumably tiltrelated transgression of the northern margin that preceded the Miocene expansion of local depocenters and their merging into a wider embayment of the Neogene Lower Magdalena basin. © 2017 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185067
作者单位	Institut des Sciences de la Terre, Université Grenoble Alpes, 1381, rue de la Piscine, Saint-Martin d'Hères, 38400, France; Grupo de Investigación en Geologia Estructural y Fracturas, Universidad Nacional de Colombia, Apartado Aéreo, Bogotá, 14490, Colombia; Department of Earth Sciences, Institute of Geochemistry and Petrology, ETH Zentrum, Clausiusstrasse 25, Zurich, 8092, Switzerland
推荐引用方式 GB/T 7714	Piraquive A.,Pinzón E.,Kammer A.,et al. Early Neogene unroofing of the Sierra Nevada de Santa Marta, as determined from detrital geothermochronology and the petrology of clastic basin sediments[J],2018,130(2021-03-04).
APA	Piraquive A.,Pinzón E.,Kammer A.,Bernet M.,&von Quadt A..(2018).Early Neogene unroofing of the Sierra Nevada de Santa Marta, as determined from detrital geothermochronology and the petrology of clastic basin sediments.Bulletin of the Geological Society of America,130(2021-03-04).
MLA	Piraquive A.,et al."Early Neogene unroofing of the Sierra Nevada de Santa Marta, as determined from detrital geothermochronology and the petrology of clastic basin sediments".Bulletin of the Geological Society of America 130.2021-03-04(2018).