The northern and western fronts of the Yorkshire Wolds are towering and precipitous, from which the land gradually and insensibly sinks into the low country of Holderness; the surface of the country everywhere, and the strata of which it is formed, dipping to the Southeast. It may in general be said to have a moderately waving surface, intersected with numerous deep, narrow, winding valleys.

The Yorkshire Wolds, forming a distinct geological and geographical entity of 1350 square kilometres, represents the northernmost outcrop of the great band of chalk which extends from the downs of Wessex, skirts East Anglia, continues through the Lincolnshire Wolds, and ends abruptly at Flamborough Head on the North Sea coast.

In East Yorkshire, the chalk forms a crescent, beginning on the River Humber foreshore at Hessle and terminates in the sheer sea-cliffs of Flamborough Head. From Hessle, it extends north-west for 46km and rises to a maximum altitude of 243m. OD in the vicinity of Wilton Beacon. It then runs eastwards for a further 46km. Until it reaches the North Sea at Flamborough.

The arc of chalk has steep west- and north-facing escarpments, which are particularly pronounced at the north-west angle where the chalk meets the limestone of the Howardian Hills. Most of the land on the Wolds is between 50m.- 200m. in elevation, in marked contrast to adjacent areas. The Vales of Pickering and York, to the north and west respectively, and Holderness, to the east, are all lower, wetter, areas, which make the Wolds, from a distance, appear rather like an island.

The chalk plateau is dissected, in dendritic fashion, by a distinctive network of dry valleys, known locally as "dales" or "slacks", probably created as a result of headward erosion. On the western side and at the north-west corner of the Wolds, these valleys are deep and steep-sided; to the south and east, the land slopes away more gently, and, here, the valleys are shallower. The largest and broadest of these, forming the major topographical feature of the northern Wolds, is the 20km. long Great Wold Valley, which runs eastwards from Wharram-le-Street to Burton Fleming, at which point it turns southwards to Rudston, and from there eastwards to Bridlington.

The Great Wold Valley contains the Gypsey Race, the only, albeit intermittent, surface stream on the "High Wolds". Although there are springs and small streams within the overall area, these are principally concentrated around the edges of the Wolds, where the chalk meets the clay of the surrounding Lowlands - as in the Kirkburn-Southburn-Eastburn-Driffield area.

The underlying solid geology is the Middle and Lower Chalk of the Creraceous, with some Red Chalk outcropping in those areas where the chalk and Lower Lias formations abutt; the chalk rests unconformably on impermeable Kimmeridge and Speeton clays. The Lower Chalk, without flints, is found on the lower slopes of the escarpment; the flinty Middle Chalk appears over the rest of the Wolds.

The chalk of the Yorkshire Wolds differs from that of the rest of England in general, is harder than elsewhere, with more marl bands, a different distribution of flints, and a different scheme of zonation.

There is almost no drift geology on the Wolds. Deposits resulting from natural erosion and deposition are limited to the chalk-gravel fills of some valley bases and to the chalky till around Flamborough and along the eastern edge of the crescent where the chalk merges with Holderness.

Everywhere, the chalk base is overlain by generally shallow, well-drained calcareous soils. Two soil types are predominant

(1) Lithomorphic soils are characteristic of the higher and steeper parns of the Wolds. These brown silty rendzina soils vary in depth, according to the thickness of bess incorporated into the chalk rubble; and

(2) brown calcareous soils with clearly developed top soil and subsoil horizons, form the major soil type on the lower, more gentle, eastern side of the Wolds.

The presence of clay and sand deposits in the deeper soils along the dip-slope causes some drainage problems and seasonal waterlogging.

The Wolds soils appear to have altered considerably over the last 5,000 years. Barrow excavations have revealed that a thick, stone-free brown forest soil existed at the time of their construction, during the Neolithic and Bronze Age. In the millennia since the Bronze Age, this changed to a thin, dark, humic soil with a high proportion of chalk rubble and a brown soil component. Almost certainly, this change occurred as a result of erosion following the clearance of the once dense forest cover.

Today, the soils of the Wolds are permeable and well structured. They dry rapidly and are cultivable in all seasons; even after rain, they are easily worked. Despite being so well drained, chalk soils and subsoils are able to make a good deal of water available to plants. Particles of chalk absorb moisture while keeping the soil open, so that the soil has the capacity to retain water without becoming too sticky for agricultural work.