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North Devon Glacial Erratics:
A Master Catalogue

All documented boulders from Madgett & Inglis (1987) with supplementary higher-level examples from Baggy Point

Compiled from published sources — 39 boulders total

The most definitive combined record available from the published literature is the Madgett & Inglis (1987) catalogue of 37 erratics — the only systematic, peer-reviewed table with grid references, dimensions, and lithologies — supplemented by two higher-level examples on Baggy Point documented by Paul Berry (2021 field observations) and Paul Madgett.

No later paper has published an updated numbered catalogue with precise altitudes for every boulder. The “suite of over twenty” sometimes quoted in popular accounts is a round-up of the 37 (mostly shoreline) plus the few higher examples. Altitudes for the 1987 set are not given individually in the paper except for No. 8 (Ramson Cliff, Baggy Point); the text states the vast majority lie on the foreshore, raised shore platforms, or in beach and raised-beach contexts, typically below 30 m OD.

Context Security — Column Guide Assessment of how reliably each boulder’s recorded position reflects original glacial emplacement. High = in situ on platform with minimal post-depositional movement; Medium = partly buried or subject to tidal influence; Low = ploughed or explicitly relocated by agricultural activity.

39Total documented

37Madgett & Inglis 1987

2Supplementary higher-level

<30mOD for most boulders

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Main Catalogue — Madgett & Inglis (1987), Nos. 1–37

Foreshore and raised-platform boulders; the majority below 30 m OD

No.	Lithology	Size (cm)	Grid Ref. (SS)	Altitude	Discoverer / Date	Context Security
1	Pink/red foliated granite	240 × 210 × 100+	44013786	<30 m (foreshore/gully)	Williams 1837	High — in situ, raised-beach context
2	Granulite gneiss (‘50-tonner’)	420 × 220 × 200+	42794001	<30 m (foreshore)	Hughes 1887	High — on planed platform
3	Quartz porphyry	150 × 135 × 100+	43803793	<30 m (foreshore)	Hughes 1887	High
4	Foliated granite/gneiss (‘White Rabbit’)	120 × 75 × 50+	43123849	<30 m (gully below HTM)	Dewey 1910	Medium — appears/disappears in shingle
5	Grey spilite	80 × 80 × 45	43933787	<30 m (foreshore)	Taylor 1956	High
6	Dolerite	29 × 13 × 5	42724005	<30 m (foreshore/cave)	Taylor 1956	Medium — tidal movement
7	Agglomerate	75 × 60 × 40	42724005	<30 m (foreshore/cave)	Taylor 1956	Medium — tidal movement
8	Epidiorite (Ramson Cliff, Baggy Point)	105 × 55 × 38	43564070	~80–85 m OD	Madgett & Madgett 1974	Low — ploughed/moved; possible manuport (see note)
9	Contorted gneiss	100 × 90 × 90+	43343813	<30 m (foreshore)	Keene 1986	High
10	Rhyolitic tuff	84 × 56 × 37	43563923	<30 m (beach/stony clay)	E.A.I. 5/81	High — embedded in alluvial context
11	Gneiss	135 × 90 × 52	43183847	<30 m	B.M. 4/82	High
12	Polymictic conglomerate	35 × 25 × 23	42754003	<30 m	P.M. 4/82	High
13	Tuff	25 × 20 × 12	42754003	<30 m	P.M. 4/82	High
14	Greenstone	55 × 40 × 30+	44423779	<30 m	E.A.I. 9/82	High
15	Granite	25 × 16 × 9	43113846	<30 m	P.M. 4/83	High
16	Meta-dolerite	30 × 19 × 12	43113849	<30 m	P.M. 4/83	High
17	Foliated microgranite	27 × 20 × 14	43113849	<30 m	P.M. 4/83	High
18	Feldspar porphyry	37 × 27 × 19	43103836	<30 m	P.M. 4/83	High
19	Rhyolitic tuff	40 × 23 × 22	43103837	<30 m	P.M. 4/83	High
20	Tuff	25 × 20 × 15	43093838	<30 m	P.M. 4/83	High
21	Feldspar porphyry	29 × 21 × 14	43083836	<30 m	P.M. 4/83	High
22	Porphyritic microgranite	125 × 95 × 60+	44033786	<30 m	P.M. 4/83	High
23	Microdiorite	33 × 17 × 6	43543925	<30 m	E.A.I. 6/83	High
24	Feldspar porphyry	25 × 19 × 14	43103850	<30 m	P.M. 7/83	High
25	Microgranite	41 × 20 × 15	43093852	<30 m	A.M. 7/83	High
26	Quartz conglomerate	27 × 19 × 11	43123837	<30 m	P.M. 7/83	High
27	Crystal tuff	31 × 23 × 15	43473920	<30 m	P.M. 7/83	High
28	Purple tuff	32 × 29 × 12	43433918	<30 m	P.M. 7/83	High
29	Granite	76 × 69 × 45	43473901	<30 m	E.A.I. 8/83	High
30	Brecciated granite	30 × 23 × 20	43473903	<30 m	E.A.I. 8/83	High
31	Rhyolite	48 × 33 × 32	43133847	<30 m	E.A.I. 5/84	High
32	Porphyritic rhyolite	35 × 28 × 18	43173822	<30 m	E.A.I. 5/84	High
33	Tuff	40 × 25 × 25	43423801	<30 m	A.M./B.M. 7/84	High
34	Amphibolite	95 × 60 × 40+	43683795	<30 m	P.M. 7/83	High
35	Brecciated lava	65 × 31 × 25+	44323782	<30 m	P.M. 8/85	High
36	Granite	40 × 28 × 25	43723794	<30 m	P.M. 12/85	High
37	Rhyolitic tuff	25 × 18 × 13	43103851	<30 m	P.M. 12/85	High

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Supplementary Higher-Level Erratics — Baggy Point

Field observations by Berry (2021) and Madgett; above ~30 m OD with known relocation history

Note on No. 8 The Ramson Cliff epidiorite (No. 8 in the 1987 catalogue) is also located on Baggy Point at ~80–85 m OD and is the boulder Brian John refers to as the ‘80 m example’. It is listed separately in the main table above as a formally numbered catalogue entry. The two boulders below are the remaining supplementary high-level examples (Brian John’s ~45 m and ~60 m examples); they have no formal catalogue numbers.

No.	Lithology	Size	Location	Altitude	Discoverer / Date	Context Security
38	Tuff / agglomerate (south wall 1)	Smaller; grey, square	Higher path south of Croyde Hoe Farm	~60 m OD	Late 1980s/1990s (ploughed)	Low — ploughed from field, placed on stone wall
39	Tuff / agglomerate (south wall 2)	Smaller; pinkish, irregular	Same wall as No. 38	~45–46 m OD	Late 1980s/1990s (ploughed)	Low — ploughed from field, placed on stone wall

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Key Notes on the Dataset

• Total documented: 39 (37 from the only formal survey + No. 8 formally listed but at high altitude on Baggy Point + 2 supplementary wall boulders). There is no published evidence for 20 separate mid-level erratics.
• Distribution: 36 boulders (Nos. 1–7, 9–37) are overwhelmingly shoreline or raised-platform in context, below 30 m OD. No. 8 (Ramson Cliff) is the sole formally catalogued high-altitude example, at ~80–85 m OD on Baggy Point.
• The three Baggy Point high-level erratics (No. 8 and the two supplementary wall boulders) are small and angular rather than beach-rounded, and were disturbed by 1970s–1990s ploughing on former arable fields. Their context security is low for the purpose of proving ice reached those altitudes.
• Context security of the shoreline cluster is generally high for depositional environment studies; the higher examples are real but their relocation history — and in the case of No. 8, the possibility that it is a manuport — means they cannot straightforwardly be used as ice-extent markers.
• The negative claim that no further mid-level erratics exist reflects the published record only. Unpublished field notes or thin-section updates from Paul Madgett could yet expand the picture.

Sources

Nos. 1–37: Madgett, P.A. & Inglis, J.B. (1987). The erratics of the North Devon coast. [Systematic catalogue with grid references, dimensions and lithologies.]

Nos. 38–39: Berry, P. (2021). Field observations, coastal-walk records (photographs of 45 m and 60 m examples, Baggy Point); Madgett, P.A., correspondence quoted by Brian John.

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