干旱区生态环境知识资源中心(Arid): Sedimentary organic matter and delta C-13(Kerogen) variation on the southern Iberian palaeomargin (Betic Cordillera, SE Spain) during the latest Pliensbachian-Early Toarcian

Arid

DOI	10.1016/j.palaeo.2019.109342
	Sedimentary organic matter and delta C-13(Kerogen) variation on the southern Iberian palaeomargin (Betic Cordillera, SE Spain) during the latest Pliensbachian-Early Toarcian
	Rodrigues, Bruno 1; Silva, Ricardo L.1,2; Reolid, Matias 3,4; Mendonca Filho, Joao Graciano 5; Duarte, Luis V.1
通讯作者	Rodrigues, Bruno
来源期刊	PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
ISSN	0031-0182
EISSN	1872-616X
出版年	2019
卷号	534
英文摘要	The Early Toarcian Oceanic Anoxic Event (T-OAE) is characterised by major palaeoenvironmental and palaeoceanographical changes (ocean anoxia, global warming, ocean acidification, among other), and a severe perturbation of the global carbon cycle. Although widespread oceanic anoxia was a significant control on the occurrence of organic-rich facies during the T-OAE in several locations of the northern Tethyan margin, the effects of anoxia, oceanic productivity, and dilution are poorly understood in other worldwide locations, such as the southern Tethyan and Iberian margins. In this study, we report new geochemical (total organic carbon (TOC), total sulphur (TS), total carbonate content (CaCO3), delta C-13 from kerogen isolates (delta C-13(Kerogen))] palynofacies and thermal maturation data from the Upper Pliensbachian Lower Toarcian successions in La Cerradura and Fuente Vidriera, External Subbetic domain, Betic Cordillera (SE Spain). The obtained results indicate that these successions have low TOC contents (similar to 0.3 wt.%), with TOC reaching up to 0.46 wt.% around the Polymorphum-Serpentinum ammonite zone boundary in La Cerradura. delta C-13(Kerogen) negative carbon isotope excursions (CIE) are observed at the base of the Polymorphum Zone, the Pliensbachian Toarcian Event (Pl-Toa), and base of the Serpentinum Zone (T-OAE). Overall, the low maturity kerogen assemblages are dominated by terrestrial OM and with a minor marine component. Small increments in terrestrial OM, non-opaque phytoclasts, and palynomorphs are observed just before and during the T-OAE in the studied area. During the Early Toarcian, in the External Subbetic domain, accumulation and preservation of OM was low and with a significant terrestrial contribution, similarly to other locations around the southern margins of Iberia and Tethys. The dominance of the opaque phytoclast subgroup, the occurrence of Classopollis, and the relatively more positive delta C-13 of terrestrial kerogen suggest that OM was mostly sourced from an area characterised by a semi-arid climate (i.e. with pronounced arid periods) during most of the Polymorphum Zone. The T-OAE negative CIE is accompanied by an increase in terrestrial OM, with a slight increase in the non-opaque phytoclast subgroup and terrestrial palynomorph subgroup. The increase of non-opaque phytoclast and terrestrial palynomorphs are in line with the posited enhancements of the hydrological cycle and export of terrestrial OM into marine environments during the T-OAE. This study suggests a link between C-13 fractionation during photosynthesis in C3 plants and climate during the Early Toarcian. This link suggests coupling of the water and terrestrial carbon cycles before and during the T-OAE.
英文关键词	Organic geochemistry Palynofacies C-13 fractionation Pl-Toa T-OAE Iberian Peninsula
类型	Article
语种	英语
国家	Portugal ; Ireland ; Spain ; Brazil
收录类别	SCI-E
WOS记录号	WOS:000504504200027
WOS关键词	OCEANIC ANOXIC EVENT ; CARBON-ISOTOPE DISCRIMINATION ; EARLY JURASSIC EXTINCTION ; TETHYS ; CLIMATE ; RECORD ; BASIN ; CYCLE ; PERTURBATION ; NANNOFOSSILS
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary ; Paleontology
WOS研究方向	Physical Geography ; Geology ; Paleontology
EI主题词	2019-11-15
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/310897
作者单位	1.Univ Coimbra, Fac Sci & Technol, Dept Earth Sci, MARE Marine & Environm Sci Ctr, Coimbra, Portugal; 2.Univ Dublin, Trinity Coll Dublin, Sch Nat Sci, Dept Geol,iCRAG, Dublin, Ireland; 3.Univ Jaen, Dept Geol, Jaen, Spain; 4.Univ Jaen, Ctr Estudios Avanzados Ciencias Tierra, Jaen, Spain; 5.Univ Fed Rio de Janeiro, Ctr Math Sci & Nat, Inst Earth Sci, Dept Geol, Rio De Janeiro, Brazil
推荐引用方式 GB/T 7714	Rodrigues, Bruno,Silva, Ricardo L.,Reolid, Matias,et al. Sedimentary organic matter and delta C-13(Kerogen) variation on the southern Iberian palaeomargin (Betic Cordillera, SE Spain) during the latest Pliensbachian-Early Toarcian[J],2019,534.
APA	Rodrigues, Bruno,Silva, Ricardo L.,Reolid, Matias,Mendonca Filho, Joao Graciano,&Duarte, Luis V..(2019).Sedimentary organic matter and delta C-13(Kerogen) variation on the southern Iberian palaeomargin (Betic Cordillera, SE Spain) during the latest Pliensbachian-Early Toarcian.PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY,534.
MLA	Rodrigues, Bruno,et al."Sedimentary organic matter and delta C-13(Kerogen) variation on the southern Iberian palaeomargin (Betic Cordillera, SE Spain) during the latest Pliensbachian-Early Toarcian".PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY 534(2019).