Geological framework model and surface data for the area south of Ammanford

Background
The original objective of this work was to a
ssemble a 1:50 000 (50k) resolution 3D Geological
Framework Model for an area south of Ammanfor
d. The model was to have two main purposes:
1. To form the basis for a communication tool
to present the 3D
geological understanding
of the area to a range of stakeholders; and
2. To support the reinterpretation of th
e geological succession
mapped at surface.
This study specifically excludes
the further development of th
e Framework Model to include
hydrogeology, hydrochemistry or rock mechanics
and does not include any consideration of
potentially suitable resources such as Coal Bed Methane.
This report provides the explanation of the me
thodology and how this model was generated.
Additional outputs of the study include:
1.
An ArcGIS project containing the da
ta used to compile the model; and
2.
Surface observations of the geology collected foll
owing Sigma workflows, held in a GIS.
Development of a 3D geological framework model
A 1:50 000 resolution 3D geological framework
model was successfully constructed for the
study area using the
Geological Surveying and Investigation in 3D
(GSI3D) software package,
developed partly in house at BGS, which can be
used readily by geologists to construct a series
of cross-sections that can more clearly display
the geological succession. Models of this type
have the potential to be accessible to members of
the public and used by geologists to assess the
potential location of resources
, not evident from traditi
onal 2D geological maps.
The approach followed was to construct a fence
diagram of 12 cross-sections using GSI3D.
These sections encompass the entire study area
and using the geologists’ expert knowledge to
incorporate surface and subsurface
data (24 deep boreholes and structural contour information
from published geological maps) provide an inte
rpretation of the geolog
ical succession at Bed,
Member and Formation level, consistent with
BGS 1:50 000-scale (50k) geological maps of the
area.