Aspects of the origin of the Solnhofen lithographic limestone facies based on a new core drilling in the Maxberg quarry

Abstract

Based on micro- and nannofacies investigations of cored limestones of a research well at the base of the Maxbergquarry near Solnhofen has changed the interpretation of the facies position of the Solnhofen Lithographic Limestone within the megafacies cycle at the end of Jurassic of the Südliche Frankenalb. The deposition environment of the Solnhofen Lithographic Limestone was part of a local deepening-trangressive cycle. The investigated core starts with a facies of shallow marine biostromes of Upper Kimmeridgian age. The bedded limestones of early Tithonian exhibit a successively decreasing sedimentary influx of a productive carbonate platform and an increasing influence of Tethyan pelagic organisms (e.g. radiolarians, Saccocoma). During the flip point of the sedimentary cycle from a transgressive to a regressive ones, the Solnhofen Lithographic Limestone was deposited under restricted conditions of a deeper water pelagic platform. Within the Mörnsheim Formation, which overlays the Solnhofen Lithographic Limestone, the normal marine environment and the influence of a closely related productive shallow marine platform area is re-established.