10.6084/m9.figshare.3454322.v1
J. Brendan Murphy
J. Brendan
Murphy
J. Duncan Keppie
J. Duncan
Keppie
R. Damian Nance
R. Damian
Nance
Brent V. Miller
Brent V.
Miller
Jaroslav Dostal
Jaroslav
Dostal
Matt Middleton
Matt
Middleton
Javier Fernandez-Suárez
Javier
Fernandez-Suárez
Teresa E. Jeffries
Teresa
E. Jeffries
Craig D. Storey
Craig D.
Storey
Geochemistry and U–Pb protolith ages of eclogitic rocks of the Asís Lithodeme, Piaxtla Suite, Acatlán Complex, southern Mexico:
tectonothermal activity along the southern margin of the Rheic Ocean
Geological Society of London
2016
Mesoproterozoic Oaxacan Complex
Ordovician
eclogitic
Acatl án Complex
1 Ga crustal source
Amphibolitic layers exhibit
Ma
origin
metasediment
Mesoproterozoic detrital zircons
megacrystic granitoid rocks
DM
Piaxtla Suite
granite
Lithodeme
data
Rheic Ocean
Geology
2016-06-21 12:03:10
Dataset
https://geolsoc.figshare.com/articles/dataset/Geochemistry_and_U_Pb_protolith_ages_of_eclogitic_rocks_of_the_As_s_Lithodeme_Piaxtla_Suite_Acatl_n_Complex_southern_Mexico___tectonothermal_activity_along_the_southern_margin_of_the_Rheic_Ocean/3454322
<p>Recent data indicating that the Piaxtla Suite (Acatlán Complex, southern Mexico) underwent eclogite-facies metamorphism and
exhumation during the Devono-Carboniferous suggest an origin within the Rheic Ocean rather than the Iapetus Ocean. The Asís
Lithodeme (Piaxtla Suite) consists of polydeformed metasediments and eclogitic amphibolites that are intruded by megacrystic
granitoid rocks. U–Pb (zircon) data indicate that the metasediments were deposited after <em>c</em>. 700 Ma and before intrusion of <em>c</em>. 470–420 Ma quartz-augen granite. The metasedimentary rocks contain abundant Mesoproterozoic detrital zircons (<em>c</em>. 1050–1250 Ma) and a few zircons in the range of <em>c</em>. 900–992 and <em>c</em>. 1330–1662 Ma. Their geochemical and Sm–Nd isotopic signature is typical of rift-related, passive margin sediments derived
from an ancient cratonic source, which is interpreted to be the adjacent Mesoproterozoic Oaxacan Complex. Megacrystic granites
were derived by partial melting of a <em>c</em>. 1 Ga crustal source, similar to the Oaxacan Complex. Amphibolitic layers exhibit a continental tholeiitic geochemistry,
with a <em>c</em>. 0.8–1.1 Ga source (<em>T</em><sub>DM</sub> age), and are inferred to have originated in a rift-related environment by melting of lithospheric mantle in the Ordovician.
This rifting may be related to the Early Ordovician drift of peri-Gondwanan terranes (e.g. Avalonia) from Gondwana and the
origin of the Rheic Ocean.
</p>