| Computer Code: |
CLAL |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Campanian Age (KC)
— Campanian Age (KC) |
| Lithological Description: |
Conglomerate (principally silicified chalk clasts) with a coarse sandstone matrix. |
| Definition of Lower Boundary: |
The lower boundary is unconformable on beds attributed to the Morvern Greensand Formation at the Clach Alasdair type site on Eigg (Braley, 1990), and unconformable on the Laig Gorge Limestone Member (erroneously given the name Strathaird Limestone Formation in Braley, 1990) at the type site of that unit on Skye. Considered to rest on the Gribun Chalk Formation elsewhere according to Mortimore, Wood and Gallois (2001). |
| Definition of Upper Boundary: |
The top of the member is not seen at the type site at Clach Alasdair on Eigg nor at Strathaird on Skye. May be unconformable beneath the Ben Iadain Mudstone Formation at Gribun, Allt na Teangaidh, Mull (Mortimore, Wood and Gallois, 2001). |
| Thickness: |
Only 0.5m at Strathaird and 0.4m at Clach Alasdair in Braley (1990) and up to 2.5m at Caisteal Sloc nam Ban, Mull in Mortimore, Wood and Gallois (2001). |
| Geographical Limits: |
Known throughout the Inner Hebrides, Eigg, Skye and Mull and in Morvern. |
| Parent Unit: |
Strathaird Limestone Formation (STRL)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Allt na Teangaidh on Mull. See Mortimore et al. (2001). |
| Reference Section |
Strathaird on Skye. See Braley (1990, 96-99). |
| Reference Section |
Caisteal Sloc nam Ban in the Wilderness, Mull. See Mortimore et al. (2001). |
| Partial Type Section |
Clach Alasdair, Eigg. This is the most complete succession identified but the top is not seen here. See Braley (1990, 87-91). |
| Reference(s): |
| Lowden, B, Braley, S, Hurst, A and Lewis, J, 1992. Sedimentological studies of the Cretaceous Lochaline Sandstone, NW Scotland. 159-162 in Parnell, J (editor), Basins on the Atlantic Seaboard: Petroleum Geology, Sedimentology and Basin Evolution. Geological Society of London Special Publication, No.62. |
| Braley, S M. 1990. The Sedimentology, Palaeoecology and Stratigraphy of Cretaceous Rocks in N.W. Scotland. Unpublished PhD Thesis CNAA, Polytechnic SouthWest (now University), Plymouth. |
| Mortimore, R N, Wood, C J and Gallois, R W, 2001. British Upper Cretaceous Stratigraphy. Geological Conservation Review Series. No. 23. (Peterborough: Joint Nature Conservation Committee.) |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
