Sedimentological and petrophysical characteristics of Solnhofen monument stones lithographic limestone: A key to diagenesis and fossil preservation
published: Aug 17, 2007
ArtNo. ESP155024501007, Price: 29.00 €
The extremely fine-grained Solnhofen Lithographic Limestone is commonly used for epitaphs, grave plates and very delicate sculptures. Furthermore the use of Solnhofen limestone as plates for roof tiles are well-known and give a marked contribution to the characteristic picture of historical houses in the Southern Franconian Alb. The technical use is based on the homogeneity and unique petrophysical parameters of the Solnhofen limestones which are caused by a special facial and diagenetic history of the rock. Porosity, permeability, pore throat diameter, and inner surface are controlled by the homogenous micro-nanostructure of the limestone which is due to the sedimentation of micritic particles into an extremely calm environment. Special geochemical conditions prevented early recrystallisation and thus resulted in the preservation of primary sedimentary characteristics of the limestone. These parameters result in e.g. an extreme low permeability which on the other hand is the prerequisite for the use of the Solnhofen limestone as lithographic limestone. The limited water uptake together with the homogenous microstructure on the one hand hinders deep penetration of surface weathering. On the other hand there seams to be no possibility for the conservation of weathered-damaged sculptures made of Solnhofen limestone because of the extremely limited permeability which just allows material transport in a diffusion scale. Fortunately, these characteristics are predominantly responsible for the good preservation of fossils found in the Solnhofen Lithographic Limestone.