Papers by Farid Chemale Jr.
Japan Geoscience Union, 2017
The Sunda Trench where the Indo-Australian Plate subducts beneath the Sunda and Burma Plate, is a... more The Sunda Trench where the Indo-Australian Plate subducts beneath the Sunda and Burma Plate, is an active seismogenic zone which generated the 2004 Mw 9.2 mega-earthquake and devastating tsunami offshore Northern Sumatra, characterized by a large shallow slip near the trench and an extremely thick (>4 km) incoming section at the deformation front. To investigate the nature and impact of the incoming section on seismogenic processes, the International Ocean Discovery Program (IODP) Expedition 362 drilled into the Indo-Australian Plate ~225 km distance from the trench at 2 primary sites offshore Northern Sumatra during August to October 2016. Here, we report preliminary results from shipboard structural observation on the recovered cores. The lithostratigraphic sequence of the oceanic plate acquired from Site 1480 consists of Unit I: subsurface calcareous and silty clay (~26.4 m), Unit II: silty clay and sand of the Nicobar Fan sequence (~26.4-1250 m), Unit III: pelagic gray-green to reddish-brown tuffaceous claystone and chalk (~1250-1327 m), Unit IV: basaltic lava flows and volcaniclastic/tuffaceous sandstone (~1327-1350 m), Unit V: chalk and calcareous claystone with magmatic intrusion/extrusion with abundant mineral veins (~1350-1420 m), and Unit VI: basaltic basement cut by veins (1420 m~). Units I and II exhibit little deformation as observed from the continuously near-horizontal bedding dips (<10°), except for several localized horizons of syn-sedimentary normal faults in Unit II and intervals of slumping and folds. The bottom of Unit II (~460 m interval) was particularly undeformed, possibly reflecting the most distal portion of the fan deposit. A distinct concentration of normal faults was observed in Unit III, characterized by primarily two sets of thin anastomosing normal faults which randomly cross-cut each other. Sand injections and lighter-colored diagenetic spots also occur in the sediments, and the normal faults generally cut through the sand injections but generally leave the diagenetic spots uncut. The flattened geometry of the diagenetic spots overprinting the normal faults and the high conjugate angle (>90°) and curvy geometry of the faults may imply that the normal faulting occurred before significant compaction.
Journal of South American Earth Sciences, 2021
Abstract The field of geochemical modelling has developed rapidly since the early 1960s when the ... more Abstract The field of geochemical modelling has developed rapidly since the early 1960s when the first attempts were made to predict the concentrations of dissolved chemical species in the seawater. Researchers have eventually realized the significance of predicting the behavior of different chemical elements in geological environments in order to understand the complexities of the chemical reactions. Henceforth, the construction of geochemical models based on numerical simulations with a set of empirical data, aims to predict the behavior of species. The constructed model is thereafter correlated with the existing geological evidence of the study area. Hereby, this work aims to generate a geochemical model capable of predicting the quality of hydrocarbon reservoirs by analyzing the diagenetic reactions between marine connate water and salt domes in a petroleum system. In order to achieve this goal, the software like PHREEQC™, GWB™ and TOUGHREACT™ (batch mode); GWB™ and TOUGHREACT™ in 1D have been used. The study area for this particular research was selected to be Gulf of Mexico where water-rock interactions occur within the turbidite reservoir of the petroleum system. Simulation results in "batch" mode at 25 °C reveals the increasing saturation index of halite and sylvite. Dependening on the variable software, the steady-state has been achieved at different time interval. In low temperatures (25°C–100 °C), there has been a convergence of results, while at higher temperatures (120°C–160 °C), however, each software generates unique curve profiles. The 1D simulations of different geochemical modelling software display reproducibility of the results. Users must be cautious while selecting a specific geochemical modelling software with a simulator, which has a compatibale temperature range for the analyses.
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
The Amazon River nutrient-rich plume currently triggers large-scale phytoplankton blooms in the o... more The Amazon River nutrient-rich plume currently triggers large-scale phytoplankton blooms in the otherwise oligotrophic western tropical Atlantic Ocean. Little is known about the onset and development of this high productivity system, although a direct link to the transcontinental Amazon River evolution can be expected. The Amazon submarine fan, located on the Brazilian Equatorial Margin (BEM), contains a unique sediment archive of the river's history and associated environmental changes in the marine realm. This study represents the first marine microfossil multi-proxy approach applied to any sedimentary record in the submarine fan area for the time interval encompassing the onset and development of the transcontinental Amazon River system. To reconstruct Miocene to Pleistocene changes in surface-and bottom water conditions we analyzed organic-walled dinoflagellate cyst-and benthic foraminiferal assemblages, respectively. Moreover, terrestrial-and freshwater palynomorph abundances were studied to provide a link between fluvial input and marine environmental changes. In addition, a planktonic foraminiferal biostratigraphy is constructed to verify the available nannofossilbased age model. Our data show that in the early-mid Miocene up to ~13 Ma limited fluvial input reached the BEM and primary productivity was elevated, after which distinctly low productivity conditions prevailed. After the birth of the transcontinental Amazon at ~9 Ma surface water productivity initially increased slightly. Consistently high surface water productivity and decreased bottom water oxygenation followed increasing terrestrial input after the (early) Pliocene. The temporal consistency between records from the Amazon Fan and the more distant Ceará Rise reflects large-scale marine environmental changes following the development of the Amazon River, likely related to increased climatic variability in the Amazon Basin during the Plio-Pleistocene.
Terra Nova, 2017
Biostratigraphic, sedimentological and provenance analyses suggest that a proto-Andean Cordillera... more Biostratigraphic, sedimentological and provenance analyses suggest that a proto-Andean Cordillera already existed in southern Peru by late Maastrichtian-late Palaeocene times. A 270-m-thick stratigraphic section shows changes in depositional environments from shallow marine (early Maastrichtian) to non-marine (late Maastrichtian) then back to estuarine (late Palaeocene) conditions. An erosional surface separates lower Maastrichtian from upper Maastrichtian deposits. Above this surface, the late Maastrichtian unit exhibits moderately developed palaeosols and synsedimentary normal faults. The sedimentary evolution is accompanied by a decrease
Precambrian Research, 2018
The Maurice Ewing Bank is located east of the Falkland/Malvinas Islands and is one of the most in... more The Maurice Ewing Bank is located east of the Falkland/Malvinas Islands and is one of the most intriguing regions of southern Gondwana. The interaction of several microplates with major cratonic areas resulted in complex displacements between Paleozoic and Cretaceous times. Here, we present combined U-Pb and Lu-Hf zircon isotopic analyses of the Maurice Ewing Bank basement to constrain the age and tectonic setting to aid in paleogeographic reconstruction. The high-grade paragneisses in the bank present dominant Late Mesoproterozoic detrital zircon age distributions with populations at 1032±12 Ma, 1068±16 Ma and 1233±8 Ma and juvenile signature (positive Hf [t] values).The gneisses are cutting by anatectic pink granite crystallized at 1006±13 Ma which formed after syn-collisional high-grade metamorphism and shows juvenile and some crustal component (Hf [t] = +1.6 to -3). The Maurice Ewing Bank basement rocks have same Stenian age and dominant juvenile signature as the arcrelated basement rocks from the Falkland/Malvinas Islands and are probably part of the same continental plateau of the South America continent. This new finding enables future reconstructions in paleogeographic models where the basement of the Falkland/Malvinas Islands and the Maurice Ewing Bank formed a single block during the Mesoproterozoic and were partly separated by crustal stretching during the opening of the Atlantic Ocean in the Late Jurassic-Cretaceous. The block played a major role in the deformation of the Cape Fold Belt from the Late Paleozoic through the Mesozoic.
Earth and Planetary Science Letters, 2017
The latitudinal displacement of the southern westerlies and associated climate systems is a key p... more The latitudinal displacement of the southern westerlies and associated climate systems is a key parameter for understanding the variations of Southern Hemisphere atmospheric circulation during the Late Quaternary Period. To increase understanding of past atmospheric circulation and of the paleoenvironmental conditions associated with continental dust sources, we dig deeper into dust provenance in paleo-archives of the Southern Hemisphere. We present here a Sr-Nd isotopic and rare earth element study of surface sediments collected along a ∼4000 km latitudinal band from arid and semi-arid terrains in southern South America. Findings from terrains that served as paleo-dust suppliers are compared with modern dust collected from monitoring stations along the same latitudinal band, which affords a test on how actual present-day aeolian compositions compare to those of the past potential source areas. Moreover, the comparison between past and present-day datasets is useful for understanding presentday atmospheric circulation. Armed with a new comprehensive dataset, we revise previous interpretations of the provenance of dust trapped in the Antarctic ice and sediments deposited in the South Atlantic sector of the Southern Ocean. These comparisons support multiple source regions in southern South America that changed with climates. The findings reveal that, although Patagonia plays an important role in contributing dust to the higher latitudes, central Western Argentina and (to a lesser extent) the southern Puna region also emerge as potentially important dust sources during glacial times. The southern Altiplano appears to be a major contributor during interglacial periods as well. We rely in part on an understanding of modern wind-dust activities to conclude that the possible presence of southern South America source regions -other than Patagonia -in East Antarctic ice is consistent with an overall equatorward displacement during glacial times of both the mid-latitude westerlies and the subtropical jet stream.
Springer Earth System Sciences, 2017
The San Rafael block is a pre-Andean geological entity situated in central-western Mendoza Provin... more The San Rafael block is a pre-Andean geological entity situated in central-western Mendoza Province, Argentina. It is part of the Cuyania composite terrane. In this terrane it is important to consider the units exposed at the ‘pre-Carboniferous’ outcrops because they record geological events before the accretion to Gondwana. One of which is the siliciclastic La Horqueta Formation of an uncertain Lower-Middle Paleozoic sedimentary age. It is characterized by asymmetric, open to similar folds, with southeast vergence. KI values obtained from the La Horqueta Formation in its type area vary from 0.24 to 0.33 Δ°2θ, indicating very low-grade (high anchizonal) to low-grade (epizonal) metamorphic conditions, that increase slightly from south to north. The white mica b-parameter measured (9.016 ± 0.007 A) suggest an intermediate pressure regime. Whole rock Rb-Sr isochronic ages were obtained on metapelites from the key outcrops in the La Horqueta area (379 ± 15 Ma, MSWD: 1.4) and in the Los Gateados area (371 ± 62 Ma, MSWD: 3.7), indicating that metamorphism and deformation occurred during the Devonian Chanic Orogenic phase, probably related to Chilenia terrane collision. U-Pb LA-MC-ICPMS detrital zircon ages patterns suggest that the La Horqueta Formation received a dominant sedimentary input from Mesoproterozoic sources, minor contributions from cratonic environments of Paleoproterozoic and Neoarchean ages, and finally a younger input from Pampean and Famatinian orogenic belts. U-Pb detrital zircon ages indicate a maximum sedimentation age close to the Silurian-Devonian limit for the La Horqueta Formation.
Journal of South American Earth Sciences
A digital composite image (PNG) is made for each core comprising core sections scanned using a li... more A digital composite image (PNG) is made for each core comprising core sections scanned using a line-scan camera. The composite layout is equivalent to traditional core table photos. Top left is top of core; color and meter rule references are included.
Gamma ray attenuation (GRA) data were acquired using a Cs-137 collimated source and a sodium iodi... more Gamma ray attenuation (GRA) data were acquired using a Cs-137 collimated source and a sodium iodide (thallium), or NaI(Tl), scintillation detector. The signal was calibrated using water and aluminum standards to provide a proxy for bulk density. This measurement was performed by a sensor mounted on either the Whole-Round Multisensor Logger (WRMSL) or the Special Task Multisensor Logger (STMSL); which track was used for a given data set is indicated in the data.
Magnetic remanence was measured on section halves (and rarely on whole-round sections) using a 2G... more Magnetic remanence was measured on section halves (and rarely on whole-round sections) using a 2G Enterprises 760R cryogenic magnetometer, first as natural remanent magnetization (NRM) and then after demagnetization steps were performed on the samples by alternating field (AF) demagnetizer coils mounted in-line within the instrument.
Report includes detailed core data: drilling and coring depths, advancement, recovered core lengt... more Report includes detailed core data: drilling and coring depths, advancement, recovered core length measured on the catwalk and final curated length, core recovery, and sections cut.
Report includes detailed information about samples taken for testing: location/depth, type/form f... more Report includes detailed information about samples taken for testing: location/depth, type/form factor, test, request number, and database identifier.
Report lists hole data: location, water depth, drilling, coring system, and core recovery.
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Papers by Farid Chemale Jr.