Phanerozoic Quartz Arenite Formation and Sequence-Analytical Patterns: Indirectly Relating to Major Impacting and Super Plume Volcanism, Jordan, Arabian Plate

Abstract

This paper deals with indirect effects of major impacting throughout the Early Paleozoic resp. with those of super plume activity during the Early Cretaceous, both applied to the siliciclastic series of Jordan deposited on the Arabian Platform, Arabian Plate. Its focus is mainly directed on gases released by both processes (CO 2 , SO 2 , NO x , HCl, HF) and the relating acids, challenged by experiments and microscopic analysis of grain mounts and thin sections that reveal chemical instability of quartz and ultrastable heavy minerals ( i.e. tourmaline) under high acidity (pH < 4). Jordan located on the northwestern edge of the stable Arabian Platform between the Arabian-Nubian Shield as source area and the Tethys Seaway, which represented throughout the Phanerozoic a remarkably “sensitive depositional environment” documented by Cruziana Ichnofacies-bearing, even thin pelite layers, intercalating the siliciclastic braid plains/braid plain deltas during the Early Paleozoic resp. by fossil-bearing Tethys incursions during the Early Cretaceous. All quartz arenites (95% - 100% quartz) analyzed exhibit an enormous loss of primary mineral assemblages of hinterland source rocks (mainly granite, granodiorite, metamorphics). The heavy mineral composition (zircon, tourmaline, rutile, anatase and brookite) varies to a high extent quantitively across architectural elements, lithofacies and formations at all, reflecting manifold reworking and resedimentation. Tourmaline shows strong progressive “hack sawing” through Cambrian/Lower Ordovician suites; angular and corroded quartz grains contrast the high compositional maturity despite long transport affection. Kaolinite dominates the clay-fraction throughout the Phanerozoic and became transformed to dickite as neoformation and cement replacing quartz! by increasing burial depth below 2000 m (T = 85 ° C - 90 ° C). According to Lopatin’s Time/Temperatur-Index the Lower Cambrian reached the onset of hydrocarbon generation (liquid window) during the Lower Early Cretaceous. Unstable heavy minerals (apatite, garnet, hornblende, epidote, zoisite/clinozoisite) are generally absent in quartz arenites while in arkosic sandstones of marine environment carbonate cement and primary clay minerals (illite) provide conservation. As known since the eighties, the K/T-event’s indirect effects had global influence on Earth’s surface sediments and atmospheric chemistry by wildfires, hot whirl storms, acidic “sturz rain”, dust, soot, darkness, loss of photosynthesis, toxic metals, gases and relating acids. All of them are here concerned and applied to major impacting throughout the Early Paleozoic using the impact data of Price (2001); while superplume volcanism during Cretaceous led to the opening of the South Atlantic accompanied by the cyclic outflow of the Para ? a/Etendeka Flood Basalts and relating gases in a gigantic scale (137 - 127 Ma). Assuming that the gases cause similar global effects on Earth’s surface sediments, an according result may be expected in form of quartz arenites and their sequence-analytical patterns (cyclic SBs, MFSs).*