𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Late Ordovician stratigraphy northwest of the Sugarloaf, mid-Wales — a discussion

✍ Scribed by D. M. D. James

Book ID
102846281
Publisher
John Wiley and Sons
Year
1990
Tongue
English
Weight
643 KB
Volume
25
Category
Article
ISSN
0072-1050

No coin nor oath required. For personal study only.

✦ Synopsis

Several modifications are proposed to the Ordovician stratigraphy recently proposed by Mackie and Smallwood (1 987), based in particular on the recognition of a major Mynydd Trawsnant anticline on the northwest flank of the Tywi structure and on field relationships indicating the Foel Formation directly to overlay the Caradoc black shale succession and directly to underlay the Craig Las Formation. The Clyn Glas Formation is suggested to have accumulated at a slope base rather than a shelf-slope break.

📜 SIMILAR VOLUMES

Discussion of ‘A late Ordovician/early S
Discussion of ‘A late Ordovician/early Silurian non-depositional slope and perched basin along the Tywi Anticline, Mid Wales’ by D. M. D. James
✍ R. A. Waters; J. R. Davies; C. J. N. Fletcher; D. Wilson 📂 Article 📅 1992 🏛 John Wiley and Sons 🌐 English ⚖ 418 KB

In Volume 26, 7-26 of the Journal, Dr D. M. D. James described the stratigraphy, sedimentology and structure of the late Ordovician to earliest Silurian succession in the core of the Tywi Anticline between the Sugar Loaf and the Wye Valley. He has used these new data to consolidate his previous mode

Palaeomagnetism of the Tan y Grisiau gra
Palaeomagnetism of the Tan y Grisiau granite, North Wales: Evidence for a subvolcanic origin in Late Ordovician times
✍ J. D. A. Piper; D. A. G. Nowell; T. P. Crimes 📂 Article 📅 1995 🏛 John Wiley and Sons 🌐 English ⚖ 734 KB

Progressive thermal demagnetization of samples from the Tan y Grisiau granite defines a coherent easterly positive characteristic remanence ( D / I = 124.9/60.3", 42 samples, R = 40.51, = 4.8") residing in magnetite. An ancient reversal of magnetization is recovered in the highest blocking temperatu

Discussion of: ‘A revision of the age of
Discussion of: ‘A revision of the age of the Hen-dy-capel ooidal ironstone (Ordovician), Llanengan, N. Wales’ by T. P. Young
✍ R. J. B. Trythall; T. P. Young 📂 Article 📅 1993 🏛 John Wiley and Sons 🌐 English ⚖ 556 KB

Hen-dy-cape1 (St Tudwal's) ooidal ironstone is of Lower Llanvirn age, based on the discovery of pendent didymograptid graptolites from a locality adjacent to the ironstone at Pen-y-gaer. These findings differ from previous published ages of Lower to Middle Llandeilo age for the Hen-dy-cape1 Ironston