Christopher Mark Fanning

Verified

Christopher verified their affiliation via an institutional email.

Learn more

Verified

Christopher verified their affiliation via an institutional email.

Learn more

• Honorary Senior Fellow at Australian National University

The southwestern margin of Amazonia hosted accretionary orogens for most of the past 2 Ga. A succession of accretionary mountain belts evolved from 2 Ga to 1 Ga, here informally grouped in the Terra Amazonica Orogen. It occupies large tracts of the Amazonian Shield, is poorly exposed and often inaccessible. Its evolution ended when Amazonia collide...

Combined heavy mineral analysis and detrital zircon geochronology have enabled us to track detritus supplied by the ancestral river systems draining the North American continent into the deep subsurface of the Gulf of Mexico, in both the coastal plain and the offshore deep water areas. During deposition of the Paleocene–Eocene Wilcox Group, sandsto...

Granitic batholiths of the ∼500 Ma Ross Orogen in Antarctica are voluminous in scale, reflecting prolific magmatism along the active early Paleozoic convergent margin of Gondwana. New age and isotopic analysis of zircons from a large suite of Ross granitoids spanning >2,000 km along the orogen provide a wealth of geochronologic, tracer, and inherit...

Our current understanding of the Ellsworth Mountains stratigraphy suggests the oldest sedimentary sequence (Heritage Group) was deposited in a Cambrian rift setting. This Early Palaeozoic age is then used as a key piercing point to help define Cambrian paleogeography for the southern paleo-Pacific margin of Gondwana, which places the Ellsworth Moun...

Remnants of coeval Devonian oceanic and continental foreland rocks are preserved in the basement of the North Patagonian Andes. Our previous studies of igneous rocks have shown the primitive oceanic and continental igneous rocks are coeval, and belong to a marginal basin that opened and closed over 50 Myr. A structural study and four new U-Pb SHRIM...

Two U-Pb zircon ages were obtained from 20 zoned crystals of fine-grained sandstones, yielding 185.6 ±1.2 Ma (CB-101) and 185.3±1.1 Ma (CB-102) (Fig. 2). The core and edge measurements of the euhedral zircons give ages between 190 and 175 Ma, suggesting an Early Jurassic igneous origin of the crystals, probably related to the initial stages of the...

The Coastal Cordillera of Central Chile (34°–37°S) holds a series of Late Triassic granitoids classically interpreted as early Andean subduction‐related magmatism based on their arc‐like geochemical signature. Here, we present geochemical, isotopic, and geochronological data and a tomotectonic analysis that challenge this idea indicating a local in...

Sedimentary rocks of the Ocoee Supergroup crop out in the Appalachian Blue Ridge of western North Carolina and eastern Tennessee. This ∼12 km thick sequence of strata was mapped as nonconformably overlying Mesoproterozoic crystalline basement (about 1.20–1.02 Ga) and beneath the lower Cambrian Chilhowee Group, leading to the traditional interpretat...

The Eocene-Miocene successions recovered at DSDP sites on the Jan Mayen Ridge (NE Atlantic) and on the adjacent East Greenland margin provide a sedimentary record of the rifting and separation of the Jan Mayen Microcontinent from East Greenland. A combination of palynology, conventional heavy mineral analysis, single-grain major and trace element g...

The North American continent has a rich record of the tectonic environments and processes that occur throughout much of Earth history. This Memoir focuses on seven “turning points” that had specific and lasting impacts on the evolution of Laurentia: (1) The Neoarchean, characterized by cratonization; (2) the Paleoproterozoic and the initial assembl...

With the aim of testing the representativity of detrital zircon U-Pb datasets, we combine new and published data from 31 large river systems in Europe and compare this information with the well-known geology of the continent. Detrital zircon ages range from Archean to Cenozoic and age clusters can be linked to different orogenic cycles and the form...

A series of arcs and volcanic chains have been emplaced in the Central Andes forearc since Upper Paleozoic to the present. These magmatic chains were distributed parallel to the trench between the Coastal Cordillera and the Chilean Pre-cordillera. The Paleocene-Middle Eocene volcanic chain is in the current Central Depression and western margin of...

Ouarzazate igneous rocks from Sidi Ifni, southwest Morocco, define a >3 km thick pile of mostly pyroclastic falls and flows of rhyolitic and dacitic ignimbrite and tuff, underpinned by comagmatic granitoid plutons. These rocks formed during two closely spaced periods of magmatism dated to c. 595–585 Ma and c. 575–560 Ma, with the majority of rocks...

The Eastern Andean Metamorphic Complex (EAMC) in southwestern Patagonia (4°-52°S) is a 450 km long belt mainly composed by low-grade metasedimentary rocks of Upper Devonian-lower Carboniferous, and Permian-lower Triassic ages. Previous works have suggested a passive margin environment for the deposition of the protolith. The EAMC comprise scarce in...

Accurate reconstruction of the Late Cretaceous paleogeography and tectonic evolution of the west- ern North American Cordilleran margin is required to resolve the long-standing debate over proposed large-scale, orogen-parallel terrane translation. The Nanaimo Basin (British Columbia, Canada) contains a high-fidelity record of orogenic exhumation an...

The Maz Metasedimentary Series is part of the Maz Complex that crops out in the sierras of Maz and Espinal (Western Sierras Pampeanas) and in the Sierra de Umango (Andean Frontal Cordillera), northwestern Argentina. The Maz Complex is found within a thrust stack of Silurian age, which later underwent open folding. The Maz Metasedimentary Series mai...

The Andean basement of NW Patagonia contains remnants of a Devonian accretionary orogen that lasted for about 50 Ma. We present and review U-Pb geochronology, major and trace element geochemistry and O- and Hf-isotope analyses of zircon for Devonian igneous and metasedimentary rocks from the western edge of the North Patagonian Massif to the Pacifi...

Here we report the first regional-scale study of Archean plutonic rocks from 50,000 km² of the northeast Democratic Republic of Congo (DRC). We include 50 new U-Pb zircon Sensitive High-Resolution Ion MicroProbe (SHRIMP) ages supported by petrographic and whole rock geochemical data from a further ~400 samples, and 39 additional U-Pb zircon ages re...

Based on chemical composition and timing of late Paleogene and Neogene igneous rocks in southern Patagonia, six igneous suites are identified and correlated with subduction processes during the approaching and subduction of active oceanic ridges. Neogene magmatism took place after a period of decreased sub-alkaline magmatism during late Paleogene (...

A.M. Macgregor (1888-1961) is remembered for his enormous contribution to geology. His maps changed the course of geological thinking in southern Africa. Following in his footsteps we examine aspects of our current understanding of the geological evolution of the Zimbabwe Craton and, using new SHRIMP U-Pb ages of zircons from felsic volcanic and pl...

The Kibali district in the Democratic Republic of Congo hosts the large Karagba-Chaffeur-Durba (KCD) deposit and smaller satellite deposits that together contained 20 million ounces (Moz) of gold when mining recommenced in 2013. An additional 3 Moz of gold was probably mined from the district before 2013. Gold deposits in the Kibali district are lo...

Previously undated low-grade metamorphic rocks from the Puerto Cisnes-Queulat area (44°30’ S) contain detrital zircons of mid-Oligocene age (ca. 28 Ma). Their outcrops represent the easternmost occurrence of the late Oligocene to early Miocene marine volcano-sedimentary Traiguén Formation; previous correlation with the Paleozoic metamorphic basemen...

The Ok Tedi copper-gold mine in Western Province, Papua New Guinea, is situated in the western part of the Ok Tedi Complex where monzodiorite to quartz monzonite intrusions are associated with porphyry- and skarn-style copper-gold mineralization. The Pleistocene age of the intrusive rocks and mineralization provides an opportunity to study the long...

The hinterland Western Domain of the Magallanes Fold-and-Thrust Belt (MFTB) between 52°-54°S is part of a poorly studied region of the southernmost Andean Cordillera. This domain consists of NNW-SSE trending tectonic slices of pre-Jurassic basement units and Late Jurassic-Early Cretaceous ophiolitic complexes and volcano-sedimentary successions of...

Previously undated low-grade metamorphic rocks from the Puerto Cisnes-Queulat area (44°30'S) contain detrital zircons of mid-Oligocene age (c. 28 Ma). Their outcrops represent the easternmost occurrence of the late Oligocene to early Miocene marine volcano-sedimentary Traiguén Formation; previous correlation with the Paleozoic metamorphic basement...

Geochronological record of plutonic activity on a long-lived active continental margin, with emphasis on the pre-Andean rocks of Chile

The Permian–Triassic is a critical period for interpreting and understanding the development of West Antarctica and its correlations into Patagonia, South America. The Antarctic Peninsula preserves isolated outcrops of Permian–Triassic age magmatic and metamorphic rocks of granodiorite, orthogneiss, paragneiss and migmatites. Outcrops from the east...

The sedimentology, petrography, and U–Pb dating of two Eocene volcaniclastic horizons of the Punta Torcida and Leticia formations, Austral basin, Tierra del Fuego, Argentina are interpreted and documented. The volcaniclastic deposits, pumicite breccia and tuffaceous sandstones, are formed by glass shards, plagioclase crystals, and pumiceous and lit...

Palynomorphs and detrital zircon U-Pb dating have provided important new age constraints for the Pirispiki Formation that crops out in the Northern Thrust Zone, Kurdistan, northern Iraq. Fauna and flora have not been previously been reported from the Pirispiki Formation at outcrop in Iraq. Spores and acritarchs recovered from the Chia Zinnar sectio...

U–Pb SHRIMP detrital zircon dating of ten samples of metamorphic “basement” rocks in north-central Chile and one granitic rock, improve knowledge of sedimentary, metamorphic and plutonic events in this segment of the Andean margin. The oldest possible sedimentation ages (Ordovician) come from a micaschist at Huentelauquén (477 Ma) and a granofels f...

The evolution of continental crust in convergent margins can be explored in southernmost South America (54-56°S). Plutonic rocks of the Fuegian Batholith and the rear-arc satellite Ushuaia Pluton were emplaced within the magmatic arc and the Fuegian fold-and-thrust belt, respectively. They record subduction zone processes in two distinct tectonic s...

Se presentan resultados preliminares de un estudio de ASM realizado en el Fiordo Reñihue, ubicado al este de la Isla Grande de Chiloé. Se recolectaron 18 sitios en rocas metavolcánicas y metasedimentarias de edad Devónico y en rocas intrusivas correspondientes al Batolito Norpatagónico de edad Neógeno. Se lograron obtener fábricas magnéticas bien d...

The giant (>20 Moz) Telfer Au-Cu deposit is located in the Paterson Province of Western Australia and is hosted by complexly deformed marine Neoproterozoic metasedimentary siltstones and quartz arenites. The Telfer district also contains magnetite- and ilmenite-series granitoids dated between ca. 645 and 600 Ma and a world-class W skarn deposit ass...

Paleoproterozoic (Rhyacian) gold deposits of the Loulo district in western Mali contain >17 million ounces (Moz) Au and form part of the second most highly endowed region within West Africa. The deposits are located within siliciclastic, marble, and evaporitic rocks of the ca. 2110 Ma greenschist facies Kofi series, which were folded and inverted b...

As the southernmost segment of the Central Asian Orogenic Belt (CAOB), the northern Alxa orogenic belt (NAOB) connects the southeastern and southwestern segments of the CAOB. The NAOB amalgamated with the closure of the Paleo-Asian Ocean; however, the closure time of the Paleo-Asian Ocean is still on great debate. In this study, we reported new det...

The scarce Eocene geological record in the Andean region of Central Chile ( c. 33.6° S) is represented by the Estratos del Cordón de los Ratones unit. This is a c. 450 m thick, mainly volcanic, continental series with a bimodal character that hosts numerous subvolcanic intrusions. The igneous products show compositional features indicating a co-gen...

The La Esperanza plutonic-volcanic complex is the largest Late Paleozoic-Early Triassic composite magmatic system of northern Patagonia. This paper reports new SHRIMP U-Pb zircon ages and K-Ar muscovite dating as well as whole-rock geochemical data for selected units. In addition, we present some new and reprocessed whole-rock Sr isotopic compositi...

This paper addresses the Jurassic-Cretaceous stratigraphic evolution of fore-arc deposits exposed along the west coast of the northern Antarctic Peninsula. In the South Shetland Islands, Upper Jurassic deep-marine sediments are uncomformably overlain by a Lower Cretaceous volcaniclastic sequence that crops out on Livingston, Snow and Low islands. U...

This paper addresses the Jurassic–Cretaceous stratigraphic evolution of fore-arc deposits exposed along the west coast of the northern Antarctic Peninsula. In the South Shetland Islands, Upper Jurassic deep-marine sediments are uncomformably overlain by a Lower Cretaceous volcaniclastic sequence that crops out on Livingston, Snow and Low islands. U...

Permian-Triassic strata in the Transantarctic Mountains and West Antarctica carry a significant detrital component derived from a contemporaneous magmatic belt along the Gondwana margin. Hf- and O-isotope characteristics were determined for near-contemporaneous (as shown by U-Pb zircon geochronology) detrital igneous zircons in Upper Permian and Tr...

Southern and western Madagascar is comprised of five tectonic provinces that, from northeast to southwest, are defined by the: (i) Ikalamavony, (ii) Anosyen, (iii) Androyen, (iv) Graphite and (v) Vohibory Domains. The Ikalamavony, Graphite and Vohibory Domains all have intermediate and felsic igneous protoliths of tonalite-trondhjemite-granodiorite...

The late Neoproterozoic São Rafael pluton, located in the Seridó Belt of the Borborema geologic province, northeastern Brazil, is an unfoliated, metaluminous, epidote-bearing, high-K calc-alkalic granitoid. Three facies are present in its northern lobe: (i) a dominant massive granite to quartz monzonite porphyritic facies containing microcline phen...

A paleomagnetic and geochronologic study was carried out on Late Permian-to-Early Triassic magmatic units exposed in the North Patagonian Massif, near the locality of Estancia La Esperanza (Río Negro Province, Argentina), to provide better paleogeographic and tectonic constraints on the evolution of Patagonia and its relations with Gondwana in the...

Geochemistry of Devonian magmatism in the Coastal Ranges of south Chile.

Geochemistry of Devonian magmatism in south Chile

The projected increase in world requirements for copper, even considering recycling, will require mining more copper over the next three decades than was mined in all prior human history. Since there are no good substitutes for copper's ubiquitous electrical uses, the failure over the past decade to discover more than a few new shallow porphyry cop...

Along the proto-Pacific margin of Gondwana, from Venezuela to northeastern Patagonia, the Early–Middle Ordovician Famatinian orogeny was the first orogenic event following assembly of the supercontinent. Previous isotope studies of the igneous and (meta-)sedimentary rocks of southwestern Gondwana yield ambiguous implications for the role of juvenil...

Previous work has shown that Devonian magmatism in the southern Andes occurred in two contemporaneous belts: one emplaced in the continental crust of the North Patagonian Massif and the other in an oceanic island arc terrane to the west, Chaitenia, which was later accreted to Patagonia. The country rocks of the plutonic rocks consist of metasedimen...

The Western Sierras Pampeanas (WSP) of Argentina record a protracted geological history from the Mesoproterozoic assembly of the Rodinia supercontinent to the early Paleozoic tectonic evolution of SW Gondwana. Two well-known orogenies took place at the proto-Andean margin of Gondwana in the Cambrian and the Ordovician, i.e., the Pampean (545–520 Ma...

The Los Menucos Complex (northern Patagonia) consists of ~6 km thick succession of acidic and intermediate volcanic and pyroclastic products, which has been traditionally assigned to the Middle/Late Triassic. New U/Pb (SHRIMP) zircon crystallization ages of 257 ± 2 Ma at the base, 252 ± 2 Ma at an intermediate level and 248 ± 2 Ma near the top of t...

The Early Paleozoic evolution of the northern margin of Gondwana is characterized by several episodes of bimodal magmatism intruded or outpoured within thick sedimentary basins. These processes are well recorded in the Variscan blocks incorporated in the Ligurian Alps because they experienced low temperature Alpine metamorphism. During the Paleozoi...

The Permo-Carboniferous tectonic setting of the SE Central Asian Orogenic Belt is poorly understood, especially with regard to the development of the Solonker (Suture) Zone. New stratigraphic, geochemical and detrital zircon analyses for Permo-Carboniferous sediments have been undertaken to resolve this problem. In the Mandula area, the Baotege For...

The geological significance of Early Paleozoic (Caledonian) magmatism and associated mineralization in South China is, as yet, poorly understood compared to the well-documented Mid-Late Mesozoic (Yanshanian) magmatism and associated mineralization. The Early Paleozoic granitoids were previously thought to be rarely mineralized. Both Caledonian gran...

The Pampean orogeny of northern Argentina resulted from Early Cambrian oblique collision of the Paleoproterozoic-Mesoproterozoic MARA block, formerly attached to Laurentia, with the Gondwanan Kalahari and Rio de la Plata cratons. The orogen is partially preserved because it is bounded by the younger Córdoba Fault on the east and by the Los Túneles-...

U-Pb SHRIMP zircon detrital ages as young as late Oligocene were obtained from two metamorphic rocks -a schist and a metaconglomerate- from the North Patagonian Andes of Aysén at the latitude of Isla Magdalena, and in a paraconglomerate sample belonging to the La Junta Formation. The maximum possible sedimentation age obtained precludes the correl...

Geochemistry of the cenozoic magmatism from Central Chilean Andes at ~35°s: preliminary results. We report the preliminary results of a geochemical, isotopic and radiometric characterization of cenozoic igneous rocks exposed in the western flank of the Andean Principal Cordillera at ~35°S. Analyzed rocks vary in age between ~45 Ma to ~5 Ma and cove...

Rock clasts entrained in glacial deposits sourced from the continental interior of Antarctica provide an innovative means to determine the age and composition of ice-covered crust. Zircon U-Pb ages from a suite of granitoid clasts collected in glacial catchments draining central East Antarctica through the Transantarctic Mountains show that crust i...

New sensitive high-resolution ion microprobe (SHRIMP) U-Pb detrital zircon ages from Cambrian to Permian−Carboniferous siliciclastic units in the Ellsworth Mountains constrain their provenance and maximum depositional age, as well as providing key information as to the tectonic evolution of a problematic region. The Cambrian Heritage Group was depo...

The gneiss complex of Wildhorse Creek (Wildhorse gneiss) forms the central component of the lowest structural plate in the Pioneer metamorphic core complex of south-central Idaho. The oldest rock in the complex is a felsic ortho­gneiss, with Neoarchean U-Pb magmatic zircon ages of 2.60–2.67 Ga. The ortho­gneiss overlaps in age and is interpreted to...

The genesis of Permian magmatism in southern South America is actively debated, particularly in relation to the origin of Patagonia. U–Pb zircon ages of c. 255 Ma for igneous rocks from the basement of Tierra del Fuego are the first evidence for southerly prolongation of this magmatism. Zircon in these rocks has εHf t values <−1 and δ ¹⁸ O > 7.4‰,...

Two main lines of evidence disagree whether or not the Patagonian blocks collided with Gondwana. All models invoke the voluminous magmatism of the La Esperanza Complex as evidence for active subduction magmatic arc or to a postcollisional setting. The evolution of this bimodal igneous suite is reassessed with field, geochronological (SHRIMP U-Pb zi...

The Betic Ophiolites consist of numerous tectonic slices, metric to kilometric in size, of eclogitized mafic and ultramafic rocks associated to oceanic metasediments, deriving from the Betic oceanic domain. The outcrop of these ophiolites is aligned along 250 km in the Mulhacén Complex of the Nevado-Filábride Domain, located at the center-eastern z...

The New England Orogen, eastern Australia, was established as an outboard extension of the Lachlan Orogen through the migration of magmatism into forearc basin and accretionary prism sediments. Widespread S-type granitic rocks of the Hillgrove and Bundarra supersuites represent the first pulse of magmatism, followed by I- and A-types typical of cir...

Late Paleozoic basaltic volcanism widely occurred in central Inner Mongolia, the southeastern part of the Central Asia Orogenic Blet (CAOB). Three volcanic pulses are identified by ion microprobe (SHRIMP II) zircon U-Pb analysis, which are Late Carboniferous (ca. 315 Ma), the latest Carboniferous (ca. 303 Ma) and early Permian (ca. 284 Ma). Basalts...

Results from new geologic mapping, SHRIMP U-Pb geochronology, and petrologic studies indicate that Mesoproterozoic basement in the northern French Broad massif near Mount Rogers consists of multiple, mostly granitic plutons, map- and outcrop-scale xenoliths of pre-existing crustal rocks, and remnants of formerly overlying meta-sedimentary lithologi...

Early Jurassic silicic volcanic rocks of the Chon Aike Province (V1: 187 – 182 Ma) are recognized from many localities in the southern Antarctic Peninsula and NE Patagonia and are essentially coeval with the extensive Karoo (182 Ma) and Ferrar (183 Ma) large igneous provinces of pre-breakup Gondwana. Until recently, plutonic rocks of this age were...

The scarce remnants of Earth's earliest history make it challenging to describe the crust-forming processes that operated during that time, and all evidence that survived subsequent tectonism and recycling deserves to be studied closely. We present geologic, petrologic, geochemical, and isotopic descriptions of Paleoarchean gneisses in the central...

From 2006 to 2013, Black Gold Energy, Niko Asia, and their partner companies, conducted geological field programs throughout eastern Indonesia in support of their oil and gas exploration efforts in the region. One hundred and fifty-one field samples, primarily of sandstones of Mesozoic and Tertiary age were collected for U-Pb dating of detrital zir...

Serpentinites and fresh or partially serpentinized harzburgite crop out in the western slope of the North Patagonian Andes of continental Chiloé (41°44'-42°12'S). These rocks are spatially associated with low-grade metamorphic rocks containing Cenozoic detrital zircons. The metamorphic rocks, together with Devonian metasediments, have been mapped p...

The Pea Ridge iron oxide-apatite (IOA) deposit is one of the major rhyolite-hosted magnetite deposits of the St. Francois Mountains terrane, which is located within the Mesoproterozoic (1.5–1.3 Ga) Granite-Rhyolite province in the U.S. Midcontinent. Precise and accurate determination of the timing and duration of ore-forming processes in this depos...

Rare earth element (REE)-rich breccia pipes (600,000 t @ 12% rare earth oxides) are preserved along the margins of the 136-million metric ton (Mt) Pea Ridge magnetite-apatite deposit, within Mesoproterozoic (1.47 Ga) volcanic-plutonic rocks of the St. Francois Mountains terrane in southeastern Missouri, United States. The breccia pipes cut the rhyo...

The most complete Permian-Triassic Gondwana succession in Antarctica crops out in the central Transantarctic Mountains. The lower Permian strata were deposited in an intracratonic basin that evolved into a foreland basin in late Permian time. Sedimentary petrology and paleocurrent data have been interpreted as indicating a granitic (craton) provena...

En esta contribución se presentan los resultados preliminares de una caracterización del magmatismo cenozoico de los Andes chilenos a los 35°S, trabajo que se enmarca dentro de la investigación de M.Sc. de la primera autora. En Chile central (33-36°S) la cordillera de los Andes está dominada por afloramientos de rocas ígneas cenozoicas que represen...