Welsh Borderland - Worcester to Great Malvern: Difference between revisions

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This area includes the low ground in the westernmost part of the region around Worcester and extending south to Great Malvern. It is bounded to the west by the ridge of the Malvern Hills.
This area includes the low ground in the westernmost part of the region around Worcester and extending south to Great Malvern. It is bounded to the west by the ridge of the Malvern Hills.


===Sedimentary Bedrock===
===Sedimentary bedrock===
The rocks in this area differ markedly in their nature and age from the rest of the Welsh Borderland region, lying east of a large geological fault (the Malvern Fault) which defines the eastern edge of the Malvern Hills. Movement on this fault uplifted the Malverns and produced an area of lowered topography to the east as today, within which sediments accumulated that were deposited by rivers and at times under desert conditions by the action of the wind. The sedimentary bedrock layers at the surface are the youngest rocks in the region at 240 to 200 million years old. These mudstones, commonly referred to by geologists as Mercia Mudstone, are mostly red, and are tilted towards the southeast. These layers extend to a depth of about 100 m next to the Malvern Fault and lie progressively deeper to the east reaching a depth of about 400 m at the easternmost edge of the region. Underlying the red mudstone is a thick sequence of sandstones and pebbly sandstones, referred to as the Sherwood Sandstone. This unit extends to a depth of about 2000 m below the surface directly east of the East Malvern Fault, and descends even deeper towards the eastern margin of the region. This thick sequence of sandstone was deposited in an ancient arid desert crossed by major rivers. As elsewhere in England and Wales the Sherwood Sandstone is an important aquifer used for drinking water supply with water flow occurring mainly between the individual sand grains that make up the rock and also within fractures in the sandstone.
The rocks in this area differ markedly in their nature and age from the rest of the Welsh Borderland region, lying east of a large geological fault (the Malvern Fault) which defines the eastern edge of the Malvern Hills. Movement on this fault uplifted the Malverns and produced an area of lowered topography to the east as today, within which sediments accumulated that were deposited by rivers and at times under desert conditions by the action of the wind. The sedimentary bedrock layers at the surface are the youngest rocks in the region at 240 to 200 million years old. These mudstones, commonly referred to by geologists as Mercia Mudstone, are mostly red, and are tilted towards the south-east. These layers extend to a depth of about 100 m next to the Malvern Fault and lie progressively deeper to the east reaching a depth of about 400 m at the easternmost edge of the region. Underlying the red mudstone is a thick sequence of sandstones and pebbly sandstones, referred to as the Sherwood Sandstone. This unit extends to a depth of about 2000 m below the surface directly east of the East Malvern Fault, and descends even deeper towards the eastern margin of the region. This thick sequence of sandstone was deposited in an ancient arid desert crossed by major rivers. As elsewhere in England and Wales the Sherwood Sandstone is an important aquifer used for drinking water supply with water flow occurring mainly between the individual sand grains that make up the rock and also within fractures in the sandstone.


[[Category:11. Welsh Borderland | 04]]
[[Category:11. Welsh Borderland | 04]]

Revision as of 15:58, 16 October 2014

This area includes the low ground in the westernmost part of the region around Worcester and extending south to Great Malvern. It is bounded to the west by the ridge of the Malvern Hills.

Sedimentary bedrock

The rocks in this area differ markedly in their nature and age from the rest of the Welsh Borderland region, lying east of a large geological fault (the Malvern Fault) which defines the eastern edge of the Malvern Hills. Movement on this fault uplifted the Malverns and produced an area of lowered topography to the east as today, within which sediments accumulated that were deposited by rivers and at times under desert conditions by the action of the wind. The sedimentary bedrock layers at the surface are the youngest rocks in the region at 240 to 200 million years old. These mudstones, commonly referred to by geologists as Mercia Mudstone, are mostly red, and are tilted towards the south-east. These layers extend to a depth of about 100 m next to the Malvern Fault and lie progressively deeper to the east reaching a depth of about 400 m at the easternmost edge of the region. Underlying the red mudstone is a thick sequence of sandstones and pebbly sandstones, referred to as the Sherwood Sandstone. This unit extends to a depth of about 2000 m below the surface directly east of the East Malvern Fault, and descends even deeper towards the eastern margin of the region. This thick sequence of sandstone was deposited in an ancient arid desert crossed by major rivers. As elsewhere in England and Wales the Sherwood Sandstone is an important aquifer used for drinking water supply with water flow occurring mainly between the individual sand grains that make up the rock and also within fractures in the sandstone.