Abstract
Red cherts from Kawakawa Bay near Auckland have yielded Late Triassic and Early Jurassic radiolarians. The cherts occur as blocks in melanges that have a green argillite matrix containing Middle and Late Jurassic (Callovian-Oxfordian) radiolarians. The melanges mark fault zones along which the Waipapa terrane has been imbricated. Callovian-Oxfordian green argillites are also found in stratigraphic contact with overlying Kimmeridgian-Tithonian green argillites and gray terrigenous clastics. The Late Triassic and Early Jurassic radiolaria are Tethyan, but the Middle and Late Jurassic faunas are dominantly non-Tethyan because the two sets of faunas are of low-latitude and of high-latitude origin, respectively, or because they originated in areas of differing ocean productivity. Occurrence of both Late Triassic and Early Jurassic radiolarians in one red chert horizon indicates sedimentary reworking.
