1) These were pits in areas of marshy ground.
The term is first noted in an undated thirteenth-century charter: novem acras terrć … quam tenui de Willelmo Tosti … viz. totam terram quam habui ad Mirepittes et apud Norlangythemore, Marton in Cleveland. The same word occurs much later: 1619-21 And thence even suth till the mire pit in the slade … And sithne fra the mire pit even suth till the greene how, Ruston
1657 to make her fence sufficient att the upper end of John Beaumont Mierpittes, South Crosland. On a map of Southowram and Rastrick, dated 1625, the place-name Blackmyrepitts was written in a steaner or oxbow of the Calder and since ‘Carr Pit’ in Dalton and Nook Pitts in Linthwaite occur in similar locations, one possible inference is that these were places where alluvium or black earth was being extracted, in order to enrich land elsewhere in those townships
the practice can be compared with that of warping in lowland parishes. It seems to be implicit in a number of documents which make no mention of the place-name. In Methley, for instance, which also adjoins the river Calder, tenants had a customary right of way to the town Mires, and two men were fined in 1516 because they failed to clean a ditch between the Myers and Stener, which again places the mires in an oxbow. In 1578, the ditch was described as lying between Stenderfurth and the Towne myres. In 1755, the Revd Joseph Ismay of Mirfield wrote in his diary about agriculture in the parish, and included ‘black earth’ up to twelve feet in depth among the useful commodities found there. He was clearly aware of how deep the reserves were so there may have been pits where it was being extracted. In 1851, a Meltham carrier was paid for 8 loads of black earth from Meltham Moor. The common minor place-names Black Mires and Black Pits may therefore be additional evidence of upland ‘warping’: 1570-1 ‘in the same field in a place called black pitts', Kilnhurst.