Lithospheric sources of North Florida, USA tholeiites and implications for the origin of the Suwannee terrane

Heatherington, Ann L.; Mueller, Paul A.

doi:10.1016/s0024-4937(98)00063-2

Cited by 44 publications

(23 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In continental tholeiites, depletion of HFSE has been linked to partial melting of subcontinental lithospheric mantle generated in an earlier convergent event (Thompson et al 1983; Pegram 1990), or crustal contamination (Cox & Hawkesworth 1985). Ti/Y, Ti/Zr, Y/Nb and Zr/Nb ratios, as well as Sc–Zr levels in Langton Dolerite samples, are identical to values for continental tholeiites from Florida, believed to be derived from a subcontinental lithospheric mantle source (Heatherington & Mueller 1999). Samples from the Langton Dolerite plot in the continental basalt field on the Y/15–La/10–Nb/8 plot (Cabanis & Lecolle 1989) (Figure 8), intermediate between the earlier formed, closely arc‐related Gympie Group rocks, and clearly asthenospheric (N‐ and E‐MORB‐like) basalts of backarc basin origin from the nearby Lower Permian Cambroon beds – Cedarton Volcanics (Sivell & McCulloch 1997).…”

Section: Geochemistry and Nd‐isotope Systematicssupporting

confidence: 62%

Geochemical and Nd‐isotopic systematics of the Permo‐Triassic Gympie Group, southeast Queensland

Sivell

McCulloch

2001

Australian Journal of Earth Sciences

View full text Add to dashboard Cite

Nine subduction‐related magma suites are recognised from drillcore in the Upper Palaeozoic – Mesozoic volcanic–intrusive sequence of the Gympie Group, part of the tectonically anomalous Gympie Province, southeast Queensland. Magmas of the Gympie Group include Lower Permian submarine (later subaerial) island‐arc tholeiites, basaltic tuff‐breccias and lavas comprising the Highbury Volcanics, as well as andesites and dacites in the unconformably overlying Rammutt Formation. Mantle‐derived mafic–intermediate magmas also comprise several intrusive suites in the Gympie Group, some possessing alkaline and shoshonitic affinities. Most eruptives of the Highbury Volcanics and Rammutt Formation show uniformly high Nd‐isotope ratios [εNd(270 Ma) = +7.4 to +8.1] and geochemical features (e.g. high Zr/Nb, Sr/Nd and La/Nb) that reflect depleted asthenospheric mantle sources metasomatised by hydrous fluids from subducted lithosphere. Predominant andesites from the Rammutt Formation have higher Zr/Y, Nb/Y, Ti/V, La/Y, P/Nd and K/P than isotopically similar basalts of the Highbury Volcanics, as well as high Al2O3, Zr and SiO2. The andesites may represent island‐arc tholeiite magmas that assimilated as much as 40% isotopically primitive (young) terrigenous sediment, akin to turbiditic greywacke of Carboniferous accretionary complex origin in contiguous terranes of the New England Orogen. Rare dacites from the Rammutt Formation differentiated from island‐arc tholeiite magmas similar to those of the Highbury Volcanics without incorporation of substantial metasedimentary components. Lower initial Nd‐isotopic ratios characterise Gympie Group intrusive suites. In order of emplacement, these are: (i) the transitional–alkaline multiphase Langton Dolerite sill (εNd = +6.2 to +6.7); (ii) dolerite dykes intimately associated with gold mineralisation (εNd = +4.3 to +5.7); and (iii) microdiorite dykes (εNd = +4.5 to +4.7) that include some near‐primary magmas with features transitional toward those of shoshonites. Low εNd(T) values (εNd = +4.9 to +5.4) are also shown by a unit of ankaramitic basalts from the top of the Highbury Volcanics. In addition to a predominantly depleted asthenospheric mantle source, isotopically enriched source component(s) are required for these low‐εNd magmas. Higher TiO2, Nb, Zr, Ti/V, Nb/Y and Nb/Zr for samples from the Langton Dolerite than for earlier formed lavas of the Gympie Group are also compatible with an enriched mantle contribution. High Zr/Y, La/Y, Ba/Zr, Th/Yb and La/Nb compared to (asthenosphere‐derived) backarc basalts from the contiguous Cambroon beds (εNd = +9 to +10), probably owe their origin to interaction of asthenospheric melts with older (isotopically evolved) subcontinental lithospheric mantle. A further component is required to account for distinctive Th‐, K‐ and Si‐enrichments (e.g. Th/La up to 0.45) of the microdiorite–shoshonite dykes and some primitive ankaramites and dolerite dykes. These enrichments are independent of uniform isotopic compositions and favour hybridisation of the mantle...

show abstract

Section: Geochemistry and Nd‐isotope Systematicssupporting

confidence: 62%

Geochemical and Nd‐isotopic systematics of the Permo‐Triassic Gympie Group, southeast Queensland

Sivell

McCulloch

2001

Australian Journal of Earth Sciences

View full text Add to dashboard Cite

show abstract

“…The crystalline basement in northern and central Florida is identified as the Suwannee terrane, a continental fragment of Gondwana origin that extends from southern Georgia and Alabama to either the Bahamas fracture zone [ Dallmeyer , ] or southern Florida [ Heatherington and Mueller , ]. The Suwannee terrane sutured to North America at approximately 300 Ma [e.g., Dallmeyer , ; Horton et al ., ; Heatherington and Mueller , ; Heatherington and Mueller , ]. Mesozoic igneous rocks are observed in drill holes within the Suwannee terrane, with tholeitic basalts and diabases dated at 183–199 Ma in northern Florida [ Heatherington and Mueller , ].…”

Section: Eastern Gulf Of Mexico: Florida Marginmentioning

confidence: 99%

Deep crustal structure in the eastern Gulf of Mexico

et al. 2014

View full text Add to dashboard Cite

We use air gun data recorded by ocean bottom seismometers to constrain the velocity structure along Gulf of Mexico Basin Opening Line 4, a profile extending from the northwestern Florida peninsula across the Florida Escarpment to the central Gulf of Mexico. Moderately thinned continental crust with a Moho depth of 32-33 km, average sediment thickness of 6 km, and an average crustal thickness of 27 km is interpreted on the northeast end of the profile offshore Florida. Thinned and intruded continental crust is identified over a horizontal distance of 225 km where the crustal layer thins from 25 km to 6-7 km; mean seismic velocities of the crust in this region increase from 6.55 km/s to 6.95 km/s from northeast to southwest and are evidence for increased magmatic input as rifting developed. Oceanic crust with an average thickness of 5.6-5.7 km is observed over a distance of 175 km on the southwest end of the profile, with an extinct spreading ridge with an axial valley morphology imaged on a coincident seismic reflection profile. Anomalously high upper oceanic crust velocities of 6.0-6.7 km/s are interpreted as massive basalt flows and could reflect increased temperatures during emplacement. Integrating well, seismic reflection and our seismic refraction data allow us to estimate a full-spreading rate of 2.2 cm/yr for seafloor spreading along the profile; this indicates that oceanic crust was emplaced at a slow-spreading center.

show abstract

“…This correlates with the Trans-Amazoninan/Eburnean Orogens dated from 1900-2250 Ma (Hartmann, 2002;Schofield and Gillespie, 2007;Park et al, 2010) and the Pan-African/Brasiliano Orogens dated from 530-680 Ma (Hoffman, 1999;Park et al, 2010). Other less abundant age populations identified include 2433 Ma and 2700 Ma (Heatherington and Mueller, 1999). These ages are coeval with ages 2450-3040 Ma for metamorphic and igneous rocks of the Archean Terrane (U-Pb; Schofield and Gillespie, 2007).…”

Section: Suwannee Terranesupporting

confidence: 62%

“…These consist of Lower Ordovician quartz arenites and Ordovician to Middle Devonian shales and siltstones (Chowns and Williams, 1983;Arthur, 1988;Dallmeyer, 1989). Detrital zircon age populations previously found in these sediments include a dominance of 515-635 Ma and 1967-2250Ma (Mueller, 1994Heatherington and Mueller, 1999). This correlates with the Trans-Amazoninan/Eburnean Orogens dated from 1900-2250 Ma (Hartmann, 2002;Schofield and Gillespie, 2007;Park et al, 2010) and the Pan-African/Brasiliano Orogens dated from 530-680 Ma (Hoffman, 1999;Park et al, 2010).…”

Section: Suwannee Terranementioning

confidence: 99%

Provenance of the Upper Jurassic Norphlet and Surrounding Formations from U-Pb Detrital Zircon Geochronology

Lisi¹

View full text Add to dashboard Cite

show abstract

Lithospheric sources of North Florida, USA tholeiites and implications for the origin of the Suwannee terrane

Cited by 44 publications

References 63 publications

Geochemical and Nd‐isotopic systematics of the Permo‐Triassic Gympie Group, southeast Queensland

Geochemical and Nd‐isotopic systematics of the Permo‐Triassic Gympie Group, southeast Queensland

Deep crustal structure in the eastern Gulf of Mexico

Provenance of the Upper Jurassic Norphlet and Surrounding Formations from U-Pb Detrital Zircon Geochronology

Contact Info

Product

Resources

About