• journal_title：Journal of the Geological Society
• Contributor：BRENT V. MILLER ; SCOTT D. SAMSON ; RICHARD S. D’LEMOS
• Publisher：Geological Society of London
• Date：2001-
• Format：text/html
• Language：en
• Identifier：10.1144/jgs.158.2.243
• journal_abbrev：Journal of the Geological Society
• issn：0016-7649
• volume：158
• issue：2
• firstpage：243
• section：Regular Article

d="p-1">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.