De miocæne Formationer i Danmark

Abstract

The Miocene Formations of Denmark.

The Miocene sediments of Denmark are restricted to the central and western part of the peninsula of Jutland. The Danish Miocene basin forms the northern part of the Miocene North Sea Basin which also covered parts of Northern Germany, Holland and Belgium. More than 200 metres of mainly micaceous clays and sands, often richly fossiliferous, were deposited. The distribution and thickness of the Miocene in Denmark is shown on the map, fig. 1, page 10.

Since long the Danish Miocene has been subdivided time-stratigraphically in a Lower, Middle, and Upper division on the basis of paleontological studies by J.P.J. Ravn (1907) and Nørregaard (1916). Works by Sorgenfrei (1940, 1958) and Rasmussen (1956) recently increased our knowledge of the Danish Miocene molluscan faunas and formations.

The following 6 formations are now recognized in the Miocene of Denmark (cf. fig. 7, page 41):

6. Gram formation (marine). Rasmussen 1956, p. 16 (Age: Upper Miocene).

5. Hodde formation (marine). This paper, p. 32 (Age: Middle Miocene).

4. Odderup formation (limnic). This paper, p. 30 (Age: Middle Miocene).

3. Arnum formation (marine). Sorgenfrei, 1958, p. 28 (Age: Middle Miocene).

2. Ribe formation (limnic). Sorgenfrei, 1958, p. 28 (Age: Middle or Lower Miocene).

1. Klintinghoved formation (marine). Klintinghoved clay, Sorgenfrei, 1940, p. 68 (Age: Lower Miocene).

The type section of the Odderup formation is defined as the interval from 28,2 to 40,3 m below surface in DGU well file no. 103.50 (at Odderup Brickworks). The form ation consists of limnic sediments of quartz sands with lignite.

The type section of the Hodde formation is from 13,8 to 23,4 m below surface in the well DGU well file no. 113.33 a, Hoddemark (NE of Varde). The formation consists of marine sediments of micaceous clays and sands with beds of quartz sand.

The distribution of the Marine Middle Miocene of Denmark is shown on map, fig. 2, page 30 and the distribution of the Marine Upper Miocene is shown on map fig. 4, page 34.