Abstrakt
In Denmark most of the water used in private households, in the industry
and for irrigation in agriculture comes from subsurface aquifers. Some
of the most important aquifers in Jylland, western Denmark, are sand
layers deposited from 23 to 15 Ma ago, in the Early Neogene (Early to
Middle Miocene). About 23 Ma ago, in the Early Miocene, the coastline
ran NW–SE across present-day Jylland (Rasmussen 2004). Global climatic
variations led to major sea-level changes (Zachos et al. 2001),
which in combination with increased sediment transport from the north
(the present Norway) resulted in deposition of several huge,
fluvio-deltaic sand systems intercalated with marine clay (e.g.
Rasmussen 1961; Rasmussen 2004; Rasmussen & Dybkjær 2005). The
Geological Survey of Denmark and Greenland (GEUS) and the regional
Environment Centres (the former counties (amter)) in Jylland are working
in close cooperation to study the Early Neogene succession; the main
purposes are: (1) to find new aquifers, (2) to map the extent of known
aquifers and clarify their mutual relationships, in order to evaluate
the size of the water resources and optimise production, and (3) to
protect the aquifers from pollution due to leaching from the surface. In
order to map the complex sedimentary succession, it has been necessary
to combine several geological disciplines, including seismic
interpretation, sedimentology, correlation of geophysical logs, and
biostratigraphy (e.g. Dybkjær 2004; Rasmussen 2004; Rasmussen et al.
2004; Piasecki 2005; Rasmussen & Dybkjær 2005; Dybkjær &
Rasmussen 2007). This article shows some results of a detailed
dinoflagellate cyst stratigraphy, which is based on an extensive
database (Fig. 1). We present here for the first time a dinoflagellate
cyst zonation for the complete Neogene succession in the Danish area.
Originalsprog | Engelsk |
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Sider (fra-til) | 29–32 |
Antal sider | 4 |
Tidsskrift | Geological Survey of Denmark and Greenland Bulletin |
Vol/bind | 15 |
DOI | |
Status | Udgivet - 10 jul. 2008 |
Programområde
- Programområde 3: Energiressourcer