...J. H. Smit; Edmund Stump Abstract The La Gorce Formation is a sequence of alternating metagraywacke, phyllite, and metapelite. Three bedding associations are recognized. The predominant type consists of massive or laminated graywacke beds in delayed graded contact with overlying thin mudstones...

... overlain by Cambrian limestones, and by silicic magmatism dated ∼650 Ma. Until this study, the relationship between the deformation and the magmatism had not been known. In the La Gorce Mountains, La Gorce Formation (Beardmore Group) was tightly folded during a regional metamorphic event producing biotite...

... bimodal magmas geochemistry Liv Group rifting Ross orogeny Transantarctic Mountains The La Gorce Formation of the Beardmore Group is the oldest unit of the Ross orogen in the Queen Maud Mountains. It crops out on the cratonic, inboard side of the Queen Maud−Wisconsin Range batholith (part...

... granitoids in the Scott Glacier area ( Encarnación and Grunow, 1996 ) supports the presence of a contemporary arc during this inferred extensional event. The oldest of the contractional deformation events is expressed in the Scott Glacier region, where the La Gorce Formation of late Neoproterozoic(?) age...

... Beardmore orogeny, Antarctica: Geological evidence from the La Gorce Mountains Geological Society of American Bulletin 1986 97 953 965 Vaughan A.P.M. Millar I.L. Early Cretaceous magmatism during extensional deformation within the Antarctic Peninsula magmatic arc Journal of South...

... we present a novel study using the Li-Mg-Zn isotopic systematics of Early Cretaceous olivine websterites from the northeastern North China Craton, China, to investigate cryptic carbonatite metasomatism. Clinopyroxene in the websterites has high Ca/Al and (La/Yb) N ratios, indicating their derivation...

... is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press. DOI: httpsdoi.org/10.2138/am-2024-9482. httpwww.minsocam.org/ 111 chlorite schist (e.g., Dixon, 1968; Bröcker and Enders, 2001; Keiter et al., 2004; Marschall et al. 112 2006a, 2006b; Gorce et al., 2021; Gyomlai et al. 2022...

... decompression to M 3 sillimanite-grade conditions and migmatite dome formation. (B) Summary time chart integrates the new data with existing geochronology across the Cyclades and the timing of deformation and metamorphism within the Naxos metamorphic core complex. Age data are from (1) Lamont et al. (2020a...

... calcites are preserved in the shallow mantle in a solid-state form rather than as carbonatitic melts. The discovery of graphite and spinel in the Hannuoba carbonate xenoliths indicates that the depth of formation of the sedimentary limestone diapirs does not exceed 2.5 GPa (<70 km). The calcite...

... with late Mesozoic craton destruction. This study presents new high precision in situ sensitive high-resolution ion microprobe (SHRIMP) U-Th-Pb and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb ages for hydrothermal monazite from the largest of the Jiaodong gold deposits...

... of the Late Proterozoic Beardmore orogeny, Antarctica: evidence from the La Gorce Mountains . Geol. Soc. Am. Bull. 97 : 953 – 965 . Tack , L. ; Liégeois , J. P. ; Deblond , A. ; and Duchesene , J. C. 1994 . Kibaran A-type granitoids and mafic rocks generated by two mantle sources...

... ( c. 80 Ma) and Eocene ( c. 50 Ma) processes in their geological evolution. Interpretations suggesting that the jadeitites were formed by complete metasomatic replacement of a pre-existing rock are not fully supported by field observations. In at least some cases, the formation of jadeitite is likely...

... . 1. Pegmatites of the Karibib-Usakos-Cape Cross area, Namibia. (A) Abbabis formation (basement); (B) mica-schists, marbles and quartzite (Damara); (C) granites (Damara); (D) basalts, rhyodacites (Karoo); (E) granites (anorogenic). From Baldwin (1993) (after Keller and von Knorring, 1989...

..., 2015 ; Thomson et al., 2016 ; Gorce et al., 2019 ; Zhang et al., 2022 ), our understanding of the carbon cycle in continental subduction zones, specifically regarding the carbon species, migration mechanisms, and final storage region associated with the recycling of continental crustal carbon...

... that the Ross Supergroup contained at least two distinct tectonostratigraphic packages known as the Beardmore and Liv Groups ( fig. 2 ; Stump 1995 ). The Beardmore Group was considered to have an older (Neoproterozoic) depositional age and includes greenschist facies siliciclastic rocks known as the La Gorce...

...) J. S. ELDRED, Zapata Exploration (Ghana) W. A. FAUBION, Wainoco (Kenya) G. J. FORTEMS, Petrofina (Angola) D. C. FRITZ, Gulf Energy and Minerals (Angola) P. GORCE, ELF-RE (Somalia) B. I. D. HALE, Burmah Oil Trading (Kenya, Somalia) H. H. HIGGINS, Conoco (Somalia) A. J...

... San Andres in Cochran County, Shell’s No. 1-30-A (36) in the Southeast Dune field of Crane County, and La Gorce’s Johnson No. 1 (62) in the PHD field of Garza County. Sands in the Grayburg and San Andres also afforded new pays in the Pegasus and Germania fields of Midland County. In the former...

..., Malagasy Republic) T. J. BRADY, Occidental (Nigeria) W. R. BROWN, Buttes Gas & Oil (Guinea) R. O. BRUNNSCHWEILER, Bishop Oil & Refining (Niger) C. C. S. DAVIES, British Petroleum (Kenya) Deutsche Texaco A.G. (Somalia) A. M. DIAZ, Direccion General de la Industria, Madrid...

... Energy seismograph crews completed 2 months work on the Dunas anticline and spent 5 months in the Tenere basin. In addition, 1 month of photogeology was reported. Machens , E. , 1973 , Contribution a l’etude des formations du socle cristallin et de la couverture sedimentaire do l’ouest de...

... in the Pensacola Mountains, Antarctica: the significance of the Ross Orogen Geological Society of America Bulletin 1996 108 685 707 Stump E. Smith J.H. Self S. Timing of events during the Late Proterozoic Beardmore orogeny, Antarctica: geological evidence from La Gorce Mountains...