U-Pb geochronological constraints on the timing of plutonism, volcanism, and sedimentation, Jersey, Channel Islands, UK

• Published in: Journal of the Geological Society Vol. 158; no. 2; pp. 243 - 252
• Main Authors: Miller, Brent V, Samson, Scott D, d'Lemos, Richard S
• Format: Journal Article
• Language: English
• Published: London Geological Society of London 01.03.2001; The Geological Society of London; Geological Society; Geological Society Publishing House
• Subjects: absolute age; Brioverian; Cadomian Orogeny; Crystalline rocks; dates; Earth sciences; Earth, ocean, space; English Channel Islands; Europe; Exact sciences and technology; Geochronology; Geological time; Geology; igneous and metamorphic rocks; Igneous and metamorphic rocks petrology, volcanic processes, magmas; Isotope geochemistry. Geochronology; Jersey; Jersey Shale; metagranite; metaigneous rocks; metamorphic rocks; Neoproterozoic; Petrology; Precambrian; Prehistoric era; Proterozoic; Sediments; Stone; Tectonics. Structural geology. Plate tectonics; Thermodynamics; U/Pb; United Kingdom; upper Precambrian; volcanism; Volcanoes; Western Europe; English Channel; United Kingdom; Northeast Atlantic; North Atlantic; English Channel Islands; Western Europe; Channel Islands; Cadomian Orogeny; absolute age; Jersey; U-Pb; Channel Islands; Atlantic Ocean; Precambrian; sandstone; volcanism; Brioverian; magmatism; zircon; granites; Proterozoic; silicates; deformation; upper Proterozoic; clastic rocks; shale; nesosilicates; Europe; volcanic rocks; Ordovician; igneous rocks; U/Pb; sedimentation; Paleozoic; sedimentary rocks; plutonic rocks
• ISSN: 0016-7649; 2041-479X
• DOI: 10.1144/jgs.158.2.243

Uranium-lead dates for single and small multiple grain zircon separates are presented for the main geological units from Jersey, British Channel Islands. A turbiditic sandstone from the Jersey Shale Formation (Brioverian Supergroup) contains detrital zircons of a variety of ages, ranging from c. 2.6 to 0.6 Ga. The youngest zircons yielded nearly concordant U-Pb dates of 586.7±3.0 Ma and 587.1±2.7 Ma providing a maximum depositional age for the unit. Zircons from overlying volcanic rocks (Anne Port Rhyolite) give an upper intercept date of 582.8+3-2.7 Ma, considered to be the age of eruption. The undeformed SW Jersey granite, which intrudes and locally thermally metamorphoses the folded Jersey Shale Formation, is dated at 580+2.3-1.6 Ma. These dates constrain tightly the timing of deposition of the Jersey Shale Formation and the age of deformation on Jersey, and indicate a dynamic arc environment during the late Neoproterozoic. Zircons from the NW Jersey granite define an upper intercept date of 482.7±1.6 Ma, similar to the previously reported 40Ar/39Ar hornblende date of c. 473 Ma, confirming a renewed pulse of magmatism during the Ordovician in this sector of Cadomia.