119 



THE PEAT MOORS OF LONSDALE. 



AN INTRODUCTION. 



W. MUNN RANKIN, M.Sc. (Leeds), B.Sc.(Lond.). 



Lonsdale is a well defined drainage area lying between three 

 ancient uplifts and Morecambe Bay. To the north is the 

 Cumbrian axis, to the east the main Pennine ridge, and to the 

 south the Bowland anticlinal. Passing round the basin the 

 heights of the mountains slowly decline from some 3000 feet 

 in the north, to 2400 feet in the east, and 1400 and less in the 

 south. The first ridge is built up of the various rocks of the 

 Silurian and ordovician systems, the second chiefly of mountain 

 limestone, and the third of the Upper Carboniferous grits and 

 shales. The low-lying country is no less diversified in its 

 rock structure and, in addition, shows the variety incident upon 

 a pretty extensive glaciation. The geographical feature which 

 has the most bearing upon the distribution of peat moors in 

 the lowlands is the long, flat valleys which run inland for 

 many miles at various quarters of the Bay. These great 

 valleys reach down from the Lake District : in their upper 

 extensions dominated by slate hills or fells ; in their lower, 

 frequently closed in by great scars of Mountain Limestone. 

 The bottoms of these valleys are made of estuarine silt — a 

 sandy clay — undoubtedly brought up in times past by the 

 rush in of the tides, which undercut the bases of cliffs into small 

 caves and alcoves, now in many places miles from the sea. 

 From the shape of the valleys the incoming tide must have been 

 characterised by a bore, such as even to-day continues in the 

 estuary of the Kent. Above the alluvial deposits rest peat 

 moors, remnants of a formerly much wider extension (Fig. i). 

 According to the locality of their development, peat moors 

 may be separated into two groups : the lowland moors about 

 the river valleys and low watersheds, and the upland on the 

 ridges and slopes of the hills or fells. It would be confusing to 

 apply the terms ' Low-moor ' and ' High-moor ' to such 

 deposits, for these may also be taken as renderings of the 

 continental designations, ' Nieder-moor ' and ' Hoch-moor,' 

 which correspond to characteristics having nothing to do with 

 altitude. Indeed, as will be seen later, the greater part of our 

 lowland moors are ' Hoch-moors ' in the commoner sense of 

 the term, while ' Nieder-moors,' though not extensive, are 

 frequently developed at high altitudes. 



1910 Mar. 1. 



