Geoscience Reference
In-Depth Information
13
(a)
Figure 13.1
Orientated sample
with combined strike line and
direction of dip on the top surface
and the sample number (H01) and
way up (arrow) on the side. In this
case part of the limestone that is
fractured but nevertheless still intact
and orientated has been chosen.
Carboniferous strata, Rumbling
Kern, Northumberland, UK. (a and
b: Angela L. Coe, The Open
University, UK.)
(b)
clinometer mark the rock exactly with the line of strike,
direction of dip and either the way up (Figure 13.1) or the top.
Take note of the dip and strike. Orientated samples can also be
obtained with a drill used for palaeomagnetic studies. This is a
diamond-tipped tube of about 2 cm diameter. Samples are
obtained by drilling the rock to obtain a cylinder of rock that is
still attached at the back. This cylinder is then orientated using
a modifi ed compass-clinometer and wire to mark the core
before it is extracted.
