Gewebeansatz-Strukturen auf pyritisierten Steinkernen von Ammonoideen

3400 pyritized internal moulds of Upper Devonian, Triassic, Jurassic and Lower Cretaceous ammonoids show various soft tissue attachment structures. They are preserved as regularly distributed black patterns on the moulds. All structures can be interpreted as attachment areas of muscles, ligaments and intracameral membranes. Paired structures are developed along the umbilicus and on the flanks of the moulds, unpaired ones appear on the middle of their dorsal and ventral sides. Strong lateral muscles cause paired twin lines on the flanks of the phragmocone and of the body chamber. A ventral muscle is deduced from small rounded or crescent shaped spots in front of each septum on the ventral side. These spots are often connected, forming a band-like structure. Broad dark external bands on the ventral side of the phragmocone, ventral preseptal areas in the posterior part of the living chamber, small twin lines or oval shaped areas on the ventral side of the living chamber represent paired or unpaired attachment areas of the hyponome muscle. A middorsal muscle is documented by small roughened areas in front of each dorsal lobe. Dark spots along the umbilicus, often connected and thus forming a band-like structure (tracking band), are remains of a pair of small dorsolateral muscles at the posterior end of the soft body. Dark bands, lines and rows of small crescent shaped structures behind the tips of sutural lobes are due to spotlike fixation places of the posterior part of the mantle and their translocation before subsequent septal secretion. Devonian goniatites had a paired system of lateral and ventrolateral muscles preserved on the moulds as black or incised lines on the flanks of the living chamber and as dark preseptal areas, ventrally indented. These structures represent the attachment areas of paired lateral cephalic and paired ventral hyponome retractors. Fine black lines on the phragmocone situated parallel to the sutures (pseudosutures) represent a rhythmical secretion of camera! membranes during softbody translocation. Goniatites had a paired system of lateral and ventrolateral muscles, whilst Neoammonoids have a paired lateral and dorsolateral system, and, additionally, an unpaired system on the ventral and on the dorsal side. Mesoammonoids show only a paired lateral and an unpaired dorsal one. Fine black lines situated parallel to the saddles and behind the lobes of the suture line can be interpreted as structures left during softbody translocation and a temporary attachment of rhythmical secreted cameral membranes. Cameral membranes had supported the efficiency of the phragmocone. Only some of the observed structures are also present in recent Nautilus. Differences in the form and position of attachment sites between ammonoids and recent Nautilus indicate different soft body organizations between ammonoids and nautiloids. The attachment structures of goniatites especially of tornoceratids can be compared with those of Nautilus which indicates Richter - Gewebeansatz-Strukturen bei Ammonoideen 3 a comparable mode of life. Differences in the form and position of attachment structures between goniatites and ammonites may indicate an increasing differentiation of the muscular system in the phylogeny of this group. Different soft body organization may depend on shell morphology and on a different mode of life. On the modification or reduction of distinct muscle systems ammonoids can be assigned to different ecotypes. Based on shell morphology and the attachment areas of cephalic and hyponome retractor muscles two groups can be subdivided: - Depressed, evolute morphotypes with longidome body-chambers show only small ventral hyponome retractor muscles. Lateral cephalic retractors are not developed. These morphotypes are adapted to a demersal mode of life. Without strong cephalic retractor muscles no efficient jet propulsion can be produced. These groups represent vertical migrants with efficient phragmocone properties (multilobate sutures, cameral membranes, narrow septal spacing). - Compressed, involute moiphotypes with brevidome body-chambers show strong cephalic and hyponome retractor muscles and represent a group of active swimmers. These morphotypes were able to live at different depths, in the free water column or/and near the seafloor. They are not confined only to one habitat. Most of the examined genera and species belong to this group. Changes of the attachment structures in the course of ontogeny confirm that juveniles of Amaltheus and Quenstedtoceras lived as passive planche drifters in upper and intermediate parts of the free water column after hatching. At the end of the juvenile stage with a shell diameter of 0,3 - 0,5 cm cephalic retractor muscles developed. With the beginning of an active swimming mode of life (neanic stage) the subadult animals left the free water column and moved into shallow water habitats. Fuciniceras showed no marked changes in the attachment structures during ontogeny. This indicates that there occur no differences in the mode of life between juvenile and adult growth stages. Based on attachment structures and shell morphology of Devonian goniatites their relation to the systematic position permits statements about probable phylogenetic relationships between the Cheiloceratidae and Tornoceratidae. In some cases attachment structures of ammonites permit statements about phylogenetic relationships on family and genus level.

Geologie und Hydrogeologie im Raum Bad Pyrmont unter besonderer Berücksichtigung des Quellensystems

The hydrodynamics and hydrochemistry of salt and fresh water from solid rock aquifer systems in the Pyrmont area are described and interpreted on the basis of recent investigations including geoelectrics, isotope hydrology, soil air analysis. Theories on the source of the springs in this area are developed, which explain the different compositions of the springs and make it possible to protect them. Data from new and re-interpretated drill holes, borehole logs and outcrops suggest a revision of the geological structure of the Pyrmont dome. Bad Pyrmont is situated on a wide dome of Triassic rocks in the southern part of the Lower Saxony uplands. Inversion of the relief has caused the development of an erosional basin surrounded by prominent ridges. Deep faults developed at the crest of the dome as this part of the structure was subjected to the strongest tectonic stress. Subrosion of the Zechstein salts in the western part of the dome has caused the main salt bed to wedge out below the western part of the dome along a N-S striking structure; this structure is refered to as the „Salzhang“ (salt slope). West of the „Salzhang“, where subrosion has removed the salt bed that prevents gas rising from below, carbon dioxide of deep volcanic origin can now rise to the surface. Hydraulic cross sections illustrate the presence of extensive and deep-seated groundwater flow within the entire Pyrmont dome. While groundwater flow is directed vertically downwards in the ridges surrounding the dome, centripetal horizontal flow predominates the intermediate area. In the central part of the dome, groundwater rises to join the River Emmer, which is the main receiving water course in the central part of the eroded basin. The depth of the saltwater/freshwater interface is determinated by the weight of the superimposed freshwater body. Hydrochemical cross sections show the shape and position of the interface and document a certain degree of hydrochemical zonation of the gently mineralized fresh water. Genetic relationships between the two main water types and the hydrochemical zones of the freshwater body are discussed. The knowledge of the hydrogeological relationship in the Bad Pyrmont aquifer systems permits a spatially narrow coexistence of wells withdrawing groundwater for different purposes (medicinal, mineral, drinking and industrial water).

Die Solling-Folge (Mittlerer Buntsandstein) im Grenzgebiet Niedersachsen - Thüringen - Hessen

This paper deals with the lithostratigraphic structure of the Solling sequence (Lower Triassic, Middle Buntsandstein) in the area between the Weser river region in the west and the Thuringian Eichsfeld region in the east. Lithologic profile mapping and the gamma-ray logs of several boreholes and 40 exposures have been used to define the lithostratigraphic Classification of the Solling sequence, to mark the facies zones and to find the connection between Sediments of the Thuringian basin in the east and the Weser fault trough via the crest of the Eichsfeld-Altmark Ridge. Tectonically controlled movements of synsedimentary character are the reason for the extreme convergence within the Solling sequence and the extreme Stratigraphie gap at its base (Hardegsen unconformity, Trusheim 1961) in the region of the swells. The discussion also demonstrates the importance of fault bundles active during Triassic and responsible for the thickness pattem of the Solling sequence between the Weser fault trough and the Eichsfeld-Altmark Ridge. The largest Stratigraphie gap is present at the line Brehme (Ohm Mountains) - Beuren - Treffurt where the Solling sequence covers Av/cn/a-bearing layers of the Volpriehausen sequence. In paiticular the Ridge sequences prove the existence of a further erosion unconformity within the Solling sequence (Solling unconformity, Kunz 1965) below the Thuringian Chirotheriensandstein as found by Rohling (1986) in the North German basin at the Stratigraphie level of the Karlshafen layers.