Southern North Sea Basin drilling project

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22 févr. 2014 (il y a 3 années et 4 mois)

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Geological Survey of the Netherlands

Southern North Sea Basin drilling project

Geological Survey of the Netherlands

North Sea Basin

Coring the Cenozoic

1

Epicontinental

basin


Continuous
subsidence

during
the Cenozoic


Due to regional uplift:
shifting
patterns

of erosion and
sedimentation


Extensive
delta formation
in
Neogene and Quaternary


Excellent
archive of climate
change
, resulting from thick
sedimentary sequences


Coupling

land
-
sea
evidence of
global change

Geological Survey of the Netherlands

Coring the Cenozoic

2

Cenozoic Global Climate

Ice Sheets

Northern

Hemisphere

Large Antarctic


ice sheets

Samll

Antarctic


ice sheets

In the North Sea basin only
parts

of the Cenozoic record
are studied in detail

Geological Survey of the Netherlands

Always an
open connection
to the
Atlantic

in the North


Former
Seaways

existed to
the South and Southeast,
forming pathways for the
immigration of
exotic
elements

into the NSB


Sedimentary infill results from
shifting erosion and
sedimentation
patterns and
forms the
response
on
climate change
and

regional
tectonics
(uplift)

Coring the Cenozoic

3

North Sea Basin

SPBA Atlas, 2010, Knox et al. Chapter 12

Geological Survey of the Netherlands

SPBA Atlas, 2010, Knox et al. Chapter 12

North Sea
Basin Palaeogeography:
Late
Paleocene



Early Eocene

Coring the Cenozoic

4

Geological Survey of the Netherlands

Coring the Cenozoic

5

North Sea Basin
Palaeogeography: Mid
Eocene


Late
Oligocene

SPBA Atlas, 2010, Knox et al. Chapter 12

Geological Survey of the Netherlands

North Sea Basin Palaeogeography: Miocene


Quaternary

SPBA Atlas, 2010, Knox et al. Chapter 12

Coring the Cenozoic

6

Geological Survey of the Netherlands

Coring the Cenozoic

7

Southern North Sea Basin, depth position top chalk (
Danian
)

A.
SE Netherlands
(
Roer

Valley
Graben
): High
-
resolution analysis of the
Miocene and the Rhine
-
Meuse fluvial system.


B.

NE Netherlands
: Salt
tectonics, human
-
induced
seismicity caused by gas
production.



C
.
NW Netherlands
:
Biostratigraphic

record of
the marine influence
continuing into the
Pleistocene.

3 POTENTIAL DRILLING SITES
(onshore part of the Netherlands)

A

B

C

Geological Survey of the Netherlands

8 Ma peat formation

10 Ma fluvial
development

28 Ma marine deposits

A.
Roer

Valley
Graben

Coring the Cenozoic

8

The
Cenozoic is c. 1800 m thick and considerable Oligocene to recent subsidence
allows a
high
-
resolution analysis of the Miocene
, and of the
Rhine
-
Meuse

fluvio
-
deltaic system

Geological Survey of the Netherlands

Coring the Cenozoic

9

B
. NE
-
Netherlands

The
entire Cenozoic succession is relatively continuous but more
condensed

and affected by
salt tectonics
and where
human
-
induced seismic activity
caused by gas production can be
monitored, coupling LOFAR

Geological Survey of the Netherlands

Coring the Cenozoic

10

C
.
NW Netherlands

The Cenozoic sequence is c.
1200m

thick.
Marine influence
continues into
the Early Pleistocene which promises a
good biostratigraphical control over a
yet badly known part of the succession.

Interaction between
Rhine
-
Meuse and
Eridanos

fluvial systems.

Geological Survey of the Netherlands

Coring the Cenozoic

11

Southern North Sea opportunities


The southern North Sea Basin provides a dominantly subsiding setting, where an up to 2000 m deep
onshore borehole
is planned to drill and date the
near
-
continuous

epicontinental siliclastic Cenozoic marine, near
-
shore, deltaic and
fluvial
sedimentary successions
.


The main aims are:



1.
To improve our understanding of the
interplay

between climate change, tectonics, sediment supply and loading and
sea level variation.

2.
To provide the
first time
ever Cenozoic stratigraphic reference sequence

for the boreal realm that allows
sedimentary and palaeoclimatic studies at unprecedented resolution, and serves as a regional ‘back
-
bone’ for
numerous industry wells and seismic surveys providing 3D grip on sediment volumes and patterns.

3.
To study the detailed structure, rate of change and lead
-
lag relations of
key palaeoclimate events
in the record
during the last 65 million years, such as the Cretaceous
-
Palaeocene boundary, Early Eocene thermal optima (ETM 1
and 2), Early Oligocene glaciation and cooling, mid
-
Miocene climatic optimum, Mi1
-
7 glaciations, and the decline to
and onset of Northern hemisphere glaciations.

4.
To improve the insight in patterns and timing
of regional uplift
(e.g. Fennoscandian and Alpine regions) and the
related patterns of
change in erosion and sedimentation
.

5.
To get reliable data on the
physical and chemical
properties of the Cenozoic depositional wedge from the North Sea
Basin.

6.
To apply downhole geophysical arrays to further constrain the loci of weak tectonic and human
-
induced
seismic
events
and monitoring
acoustic noise
to image the deeper parts of the Earth's crust using passive interferometry

Geological Survey of the Netherlands

Coring the Cenozoic

12

Geological Survey of the Netherlands

Coring the Cenozoic

13