[1] Measurements of the calcium isotopic composition (dCa) of planktonic foraminifera from the western equatorial Pacific and the Indian sector of the Southern Ocean show variations of about 0.6% over the past 24 Myr. The stacked dCa record of Globigerinoides trilobus and Globigerina bulloides indicates a minimum in dCasw (seawater calcium) at 15 to 16 Ma and a subsequent general increase towar...

The analysis of an acid-soluble and acid-insoluble fraction of one systematically sampled, partially dolomitized limestone bed is reported. The original lime sediment, composed principally of skeletal remains, pellets, occasional intraclasts, detrital quartz, illite, and muscovite has been modified by the addition of calcite, dolomite, and dickite cements and has been patchily replaced by dolom...

We examine the link between organic matter degradation, anaerobic methane oxidation (AMO), and sulfate depletion and explore how these processes potentially influence dolomitization. We determined rates and depths of AMO and dolomite formation for a variety of organic-rich sites along the west African Margin using data from Ocean Drilling Program (ODP) Leg 175. Rates of AMO are calculated from ...

The present work focuses on the upper Cretaceous (Cenomanian-early Campanian) carbonate successions in selected wells from northwestern Iraq. These are represented by Gir Bir Turonian), Wajna (late Santonian) and Mushorah (early Formations. succession has affected early burial near-surface, unconformity-related deep diagenesis cementation, neomorphism, dolomitization, dedolomitization, silicifi...

Abstract Difficulties in dating Mississippi Valley–type (MVT) mineral deposits and the often closely associated dolomitization have led to controversy regarding their origin. We report first radiometric ages for Gorno mining district northern Italy, an example of Alpine subclass MVT deposits. U-Pb hydrothermal carbonates pre- postdating ore-forming event show that base-metal mineralization occu...

A detail sedimentological analysis of the Sarki Formation (Early Jurassic) in Warte and Zarwan sections Imbricated Zone, northern Iraq has been conducted for first time. The both studied are consisting dolomite, dolomitic limestone recrystallized breccia. petrographic study 80 thin analyzed outcrops showed skeletal non-skeletal components. components including ostracods, bivalves echinoderms. W...

The Microfacies analysis of the Cretaceous Mishrif Formation was studied in Nasiriyah oil field Governorate, southern Iraq using integrated borehole data set that included, core samples and well logs newly drilled to analyze microfacies Diagenesis Process formation, 100 thin sections for selected well. results show formation composed of: (top base) a fine-grained, limonitic fresh water limeston...

This trip examines exposures in the Adirondack Lowlands that contain Paleozoic hydrothermal and faultrelated features hosted by Mesoproterozoic ‘Grenville’ marbles and Cambrian Potsdam Sandstone. These features have been the source of some debate historically and are now explicable as resulting from hydrothermal activity within an ancient wrench fault system. This system is similar to the deep ...