Abstract
We re-evaluate the Neoproterozoic, Pacific-type accretionary complex on Anglesey and in the Lleyn peninsula (Wales, UK), by reconstructing its ocean plate stratigraphy (OPS). Three types of distinctive OPS were successively emplaced downwards in an accretionary wedge: the oldest at the top formed when an ocean opened and closed from a ridge to a trench, the central OPS was subjected to deep subduction and exhumed as blueschists, and the youngest at the bottom is an olistostrome-type deposit that formed by secondary gravitational collapse of previously accreted material. The three types formed by successive eastward subduction of young oceanic lithosphere at the leading edge of Avalonia. The downward growth of the accretionary complex through time was almost coeval with exhumation of the blueschist unit at 550-560 Ma in the structural centre of the complex on Anglesey. From balanced sections we have reconstructed the ocean plate stratigraphy on Llanddwyn Island from which we calculate that about 8 km of lateral shortening of ocean floor took place during imbrication and accretion; this is comparable with the history of plate subduction around the Pacific Ocean. We also calculate that the age of the subducted lithosphere was very young, probably less than 10 Ma.
| Original language | English |
|---|---|
| Pages (from-to) | 55-75 |
| Number of pages | 21 |
| Journal | Geological Society Special Publication |
| Volume | 338 |
| DOIs | |
| Publication status | Published - 2010 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Ocean Engineering
- Water Science and Technology
- Geology
Cite this
Ocean plate stratigraphy and its imbrication in an accretionary orogen : The Mona Complex, Anglesey-Lleyn, Wales, UK. / Maruyama, S.; Kawai, T.; Windley, B. F.
In: Geological Society Special Publication, Vol. 338, 2010, p. 55-75.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ocean plate stratigraphy and its imbrication in an accretionary orogen
T2 - The Mona Complex, Anglesey-Lleyn, Wales, UK
AU - Maruyama, S.
AU - Kawai, T.
AU - Windley, B. F.
PY - 2010
Y1 - 2010
N2 - We re-evaluate the Neoproterozoic, Pacific-type accretionary complex on Anglesey and in the Lleyn peninsula (Wales, UK), by reconstructing its ocean plate stratigraphy (OPS). Three types of distinctive OPS were successively emplaced downwards in an accretionary wedge: the oldest at the top formed when an ocean opened and closed from a ridge to a trench, the central OPS was subjected to deep subduction and exhumed as blueschists, and the youngest at the bottom is an olistostrome-type deposit that formed by secondary gravitational collapse of previously accreted material. The three types formed by successive eastward subduction of young oceanic lithosphere at the leading edge of Avalonia. The downward growth of the accretionary complex through time was almost coeval with exhumation of the blueschist unit at 550-560 Ma in the structural centre of the complex on Anglesey. From balanced sections we have reconstructed the ocean plate stratigraphy on Llanddwyn Island from which we calculate that about 8 km of lateral shortening of ocean floor took place during imbrication and accretion; this is comparable with the history of plate subduction around the Pacific Ocean. We also calculate that the age of the subducted lithosphere was very young, probably less than 10 Ma.
AB - We re-evaluate the Neoproterozoic, Pacific-type accretionary complex on Anglesey and in the Lleyn peninsula (Wales, UK), by reconstructing its ocean plate stratigraphy (OPS). Three types of distinctive OPS were successively emplaced downwards in an accretionary wedge: the oldest at the top formed when an ocean opened and closed from a ridge to a trench, the central OPS was subjected to deep subduction and exhumed as blueschists, and the youngest at the bottom is an olistostrome-type deposit that formed by secondary gravitational collapse of previously accreted material. The three types formed by successive eastward subduction of young oceanic lithosphere at the leading edge of Avalonia. The downward growth of the accretionary complex through time was almost coeval with exhumation of the blueschist unit at 550-560 Ma in the structural centre of the complex on Anglesey. From balanced sections we have reconstructed the ocean plate stratigraphy on Llanddwyn Island from which we calculate that about 8 km of lateral shortening of ocean floor took place during imbrication and accretion; this is comparable with the history of plate subduction around the Pacific Ocean. We also calculate that the age of the subducted lithosphere was very young, probably less than 10 Ma.
UR - http://www.scopus.com/inward/record.url?scp=79960952420&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79960952420&partnerID=8YFLogxK
U2 - 10.1144/SP338.4
DO - 10.1144/SP338.4
M3 - Article
AN - SCOPUS:79960952420
VL - 338
SP - 55
EP - 75
JO - Geological Society Special Publication
JF - Geological Society Special Publication
SN - 0305-8719
ER -