(Kimmeridge Bands of Shale and Cement Stone) - 2003

The Jurassic Rocks of Helmsdale are of the Kimmeridge Age, bands of Shale and Cement Stone are exposed on the foreshore. A massive Fault known as the 'Helmsdale Fault' makes this one of few locations in North Scotland for collecting Jurassic Fossils. The Kimmeridge exposed is extensive with a unique bed known as the 'Boulder Bed'. The Boulder bed is a hard, uneven layer of Various Kimmeridge Rocks, Broken Cement Stones & Shale. The layer is totally unpredictable and can appear suddenly, although zones have been identified in documentation which change as you walk Northwards.

From the years of erosion it is clear that something major happened at Helmsdale years ago, something with enough power to rip apart the rocks, not a slow movement but a sudden movement. Clear Zones of Cement stone and Shale can be found at the base of the Boulder Bed marking the 'undisturbed original geology'. Resting on top is the Boulder Beds which fell during this erosion often in complete stacks. The following diagram shows just how the boulder beds were laid down. One theory a tidal force caused massive cliff falls along the coast, stacks falling onto the lower beds.

(Boulder Bed with 'Stack', below beach level the original Jurassic lower Beds)

(Another example of a fallen stack)

The Helmsdale Granite rests upon the Kimmeridge rocks and can be seen in cliff faces further along the coast. The cause of the boulder bed is still a bit of a mystery there is nothing like it anywhere else, glaciation was ruled out. The current theory is that this area was tidal with extensive erosion, smashing the once high Jurassic cliffs (which would have been naturally much softer than today) or more recent theories suggest that a massive tsunami took place. It has to have happened in the Jurassic period since nothing more recent can be found in the Boulder Bed. .

Further Northwards, the Boulder Bed becomes much thicker, areas of shale also continue. Current theories suggest that these boulder bed and shales are Portlandian with the Boulder Beds and Shale further Southwards being Kimmeridgian. Stacks of fallen 'Devonian' Rocks are also mixed up within the Boulder Beds.

(Helmsdale Granite) - 2003

Jurassic	Late	Volgian	Portlandian	142 to 147
			Tithonian
				147 to 150
		Kimmeridgian		150 to 154
		Oxfordian		154 to 159.4
	Middle	Callovian		159 to 165
		Bathonian		165 to 170
		Bajocian	Late Inferior Oolite	170 to 177
			Middle Inferior Oolite
		Aalenian	Early Inferior Oolite	177 to 180.1
			Scissum Beds
			Late Bridport Sands
	Early	Toarcian (Late Lias)		180 to 190
		Pliensbachian (Middle & Early Lias)		190 to 195
		Sinemurian (Early Lias)		195 to 201
		Hettangian (Early Lias)		201 to 205.7

Portlandian 142 to 147 MYA
FORMATIONS AND DEPOSITS	LOCATIONS
Helmsdale Shale	Helmsdale
Boulder Beds	Helmsdale
Portland Stone	Dancing Ledge

Kimmeridgian 150 to 154 MYA
FORMATIONS AND DEPOSITS	LOCATIONS
Boulder Beds	Lothbeg Crakaig Helmsdale Portgower
Allt na Cuile Sandstone	Lothbeg
Kintradwell Beds	Lothbeg Crakaig Kintradwell
Three Kings Reef	Balintore
Kimmeridge Clay	Reighton Bowleaze Cove Wyke Regis Ringstead Kimmeridge Bay Chapmans Pool
Eathie Shore	Eathie

1:250 000 Geological Map of Helmsdale Geological Maps are sold either Flat or Folded for Solid, or Seabed geology. Special editions may be available for certain locations. For a complete list click the link below. Click here to BUY ONLINE from our Store

1: 50 000 Geological Map of Helmsdale Geological Maps are sold either Flat or Folded for Solid, Drift or combined geology. Special editions may be available for certain locations. For a complete list of 1: 50 000 maps, click the link below. Click here to BUY ONLINE from our Store