干旱区生态环境知识资源中心(Arid): Mineralogy and geochemistry of marine glauconitic siliciclasts and phosphates in selected Cenomanian-Turonian units, Bohemian Cretaceous Basin, Czech Republic: Implications for provenance and depositional environment

Arid

DOI	10.1016/j.chemer.2019.05.003
	Mineralogy and geochemistry of marine glauconitic siliciclasts and phosphates in selected Cenomanian-Turonian units, Bohemian Cretaceous Basin, Czech Republic: Implications for provenance and depositional environment
	Al-Bassam, Khaldoun; Magna, Tomas; Vodrazka, Radek; Cech, Stanislav
通讯作者	Magna, T (corresponding author), Czech Geol Survey, Klarov 3, CZ-11821 Prague, Czech Republic.
来源期刊	GEOCHEMISTRY
ISSN	0009-2819
EISSN	1611-5864
出版年	2019
卷号	79 期号:2 页码:347-368
英文摘要	Glauconitic siliciclastic rocks and phosphate components from the Pecinov Member of the Peruc-Korycany Formation (Upper Cenomanian), the lower part of the BIM Hora Formation (Lower Turonian) and the lower part of the Teplice Formation (Upper Turonian) are studied. Geochemical indices suggest that the siliciclasts were derived from the weathering and recycling products of variable rock types of the Bohemian Massif, with a pronounced signature of felsic-derived source lithologies and a minor contribution from the sources of a chemically intermediate nature. Geochemical and mineralogical criteria suggest that the climate in the midCretaceous was generally humid with possible intermittent arid episodes, which resulted in a long-term weathering of source rocks and the development of residual clay minerals in the source area. Several geochemical indications point toward highly reducing marine conditions during deposition of the mudstones, which are composed of quartz, glauconite, kaolinite, smectite, apatite and calcite. The glauconites show a highly mature character with > 8 wt. % K(2)o and bear evidence of long residence time near the sediment-water interface. They are depleted in Fe and rich in Al indicating a mixed layer mica-smectite as a precursor. Carbonate-fluorapatite is the only phosphate phase identified in the phosphate components, with up to 8 wt. % CO32-, excess F- and significant amounts of Na+ and SO42- in the apatite structure. A short-lived phosphogenic event (s) took place in the latest Cenomanian and involved large areas of the Bohemian Cretaceous Basin in association with the Oceanic Anoxic Event 2. The phosphate nodules were initially precipitated under suboxic conditions around the Cenomanian-Turonian boundary and were later reworked and emplaced in the earliest Turonian units. Phosphate coprolites mark another phosphogenic event in the early Upper Turonian. The development of the phosphate coprolites took place under variable redox conditions; the release of organically-bound phosphate and subsequent phosphatisation of fecal material took place under suboxic environment, followed by reworking in oxic realms.
英文关键词	Glauconite Apatite Siliciclasts Phosphogenesis Paleoclimate Provenance Cretaceous OAE2
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000494249000010
WOS关键词	ORGANIC-CARBON BURIAL ; SEDIMENTARY-ROCKS ; SEQUENCE STRATIGRAPHY ; ISOTOPE STRATIGRAPHY ; SOUTHERN APENNINES ; WESTERN-AUSTRALIA ; FOSSIL BACTERIA ; PECINOV QUARRY ; EVOLUTION ; PETROLOGY
WOS类目	Geochemistry & Geophysics
WOS研究方向	Geochemistry & Geophysics
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/369511
作者单位	[Al-Bassam, Khaldoun; Magna, Tomas; Vodrazka, Radek; Cech, Stanislav] Czech Geol Survey, Klarov 3, CZ-11821 Prague, Czech Republic
推荐引用方式 GB/T 7714	Al-Bassam, Khaldoun,Magna, Tomas,Vodrazka, Radek,et al. Mineralogy and geochemistry of marine glauconitic siliciclasts and phosphates in selected Cenomanian-Turonian units, Bohemian Cretaceous Basin, Czech Republic: Implications for provenance and depositional environment[J],2019,79(2):347-368.
APA	Al-Bassam, Khaldoun,Magna, Tomas,Vodrazka, Radek,&Cech, Stanislav.(2019).Mineralogy and geochemistry of marine glauconitic siliciclasts and phosphates in selected Cenomanian-Turonian units, Bohemian Cretaceous Basin, Czech Republic: Implications for provenance and depositional environment.GEOCHEMISTRY,79(2),347-368.
MLA	Al-Bassam, Khaldoun,et al."Mineralogy and geochemistry of marine glauconitic siliciclasts and phosphates in selected Cenomanian-Turonian units, Bohemian Cretaceous Basin, Czech Republic: Implications for provenance and depositional environment".GEOCHEMISTRY 79.2(2019):347-368.