Kennet E. Flores
Statement of research interests and goals
I am a regional field geologist who applies various techniques, including stratigraphy, structural geology, igneous, sedimentary and metamorphic petrology, geochemistry, geochronology, and sedimentology, to develop geodynamic scenarios and plate tectonic models for fossil convergent plate boundaries. Most of my field research has been focused on Central American accretionary prisms and suture zones. My other foci are the evolution and modeling of the plate tectonics of the Pacific Ocean including the Circum-Pacific convergent margins and the exhumation process of high-pressure–low-temperature (HP–LT) rocks around the world. The study of fossil accretionary prisms and suture zones allows us to understand geodynamic processes before, during, and after suturing, which includes subduction, accretion, collision, obduction and exhumation. These fundamental processes play an important role in lithospheric dynamics and the shaping and growth of continents. With these data we can better constrain the geodynamic evolution of the modern convergent boundaries and integrate it into a “big picture” of plate tectonics.
(a) Tectono-stratigraphic structure of the northern region of the Gulf of Nicoya, Costa Rica
This project examined the structure and composition of oceanic basaltic complexes and their respective sedimentary sequences in a long-lived Pacific Ocean accretionary prism. The main results of this project show the occurrence of at least two exotic terranes related to an oceanic plateau system and a mid-Cretaceous island arc complex, respectively (Denyer & Flores 2003; Flores et al., 2003a; 2003b; 2003c; Denyer et al., 2005; Flores et al., Denyer et al., 2005). These results were the baseline for a larger interdisciplinary and multi institutional research project that gave me the opportunity to travel to Europe and became enrolled in graduate school at the University of Lausanne (UNIL).
(b) Late Mesozoic-Early Tertiary evolution of the western margin of the Caribbean Plate: plateaus, arcs and pelagic palaeo-environments
During this project I worked on two main sections, as an expert regional geologist of the Central America and the Caribbean region, and developing a tectonic model to explain the tectonic evolution of the study area. In my first role, I led extensive field campaigns to key areas of Panama, Costa Rica, Nicaragua, Guatemala, Puerto Rico, and Cuba. The main purpose of this section was to understand the geochemistry, age, and origin of geodynamic markers such as oceanic basaltic complexes and deep-sea water radiolarites (e.g., Baumgartner et al., 2008; Bandini et al., 2008; 2011a; 2011b; Buchs et al., 2011; 2013). During these research field campaigns I discovered an unexpected HP–LT serpentinite mélange in NE Nicaragua (Flores et al., 2014), which expanded my original focus and turned me also onto new fields such petrology of igneous and metamorphic rocks, regional metamorphism, whole rock geochemistry, and Ar-Ar geochronology as well as the origin, evolution, exhumation and emplacement of serpentinite mélanges along convergent margins
(c) Geodynamics of Tethyan margins: rifting, accretion, collision. Paleomargins confronted to actualistic models
During this experience we developed a new methodology to integrate the compiled geological data into geodynamic scenarios which are the basis to constrain plate tectonic reconstructions. Initially, I expanded my compilation to the nearby areas of the Caribbean plate. Then, I enlarged my research to the Pacific Ocean margins, the North American, and South American Cordilleras as well as the South East Asia region in order to develop new plate tectonic models between the Permian and the Tertiary. The final product of this project section was integrated into the new UNIL-PaleoDym ArcGIS-based georeferenced plate tectonic model and geodynamic database project. In 2010, this project was sold to Neftex Petroleum Consultants Ltd. They used as a baseline to create a new Geodymanics module of their Earth Model, which provides consultant service to major oil companies such as Shell, BP, and Total. Currently, Neftex owns all rights of our plate tectonic reconstruction model. However, publications are allowed under their authorization (e.g., Verard et al., 2012).
(d) Petrogenesis of jadeitite and other high-pressure rocks in serpentinites, Guatemala Suture Zone
The Cretaceous serpentinite mélanges and metavolcanic bodies of the Guatemala Suture Zone: Constraints on protoliths and HP–LT block based on analogies with other Pacific and Caribbean sutures belts Fluid Transport and Fluid-Rock Interactions Preserved in Two Serpentinite Mélanges in the Guatemala Suture Zone This project is largely a geochemical and geochronological study to examine origin and age of jadeitites and HP–LT metabasites within the serpentinite mélanges. An important result from this project is the demonstration that jadeitite, based on U-Pb zircon ages, forms prior to the peak metamorphic events recorded by metabasite blocks in the mélanges by 10 to 30 Mya, and thus must form in the non-subducted mantle wedge during active subduction (Flores et al., 2013). These results are also consistent with an interpretation of jadeitite being fluid precipitates (Harlow & Flores, 2011). In addition, Th/U ratios are generally much lower than for suggested igneous protoliths, if these rocks were metamorphic/metasomatic in origin. Preliminary whole rock, trace element, and isotopic determinations on metabasites show a large variety of protolith geochemical signatures and metasomatic enrichment. These data suggest complex tectonic scenarios for the formation of the Guatemala Suture Zone, including subduction, accretion, collision, exhumation, and obduction of oceanic crust onto the continental margins (Flores et al., in review).
(e) Unraveling the geodynamic evolution and tectonic history of the Guatemala Suture Zone: a world-class natural laboratory
The Guatemala Suture Zone (GSZ) is the fault-bound region that contains the present North American–Caribbean plate boundary. This major composite geotectonic unit contains four major oceanic crust bodies and two serpentinite mélanges bearing HP–LT rocks such as eclogite, jadeitite, garnet-amphibolite, and blueschist. These major assemblages were previously defined as “ophiolites” and are thrust north and south of the active left-lateral transform, onto distinctly different continental metamorphic sequences within the GSZ. Classically, the GSZ has been interpreted as the result of a single progressive collision between (a) an intra-oceanic island arc attached to the continental block, and (b) a passive margin, along a transpressive sinistral system in a proto-Caribbean oceanic basin. This model has been based on the different geochemical signatures, but the data are rather limited from the “ophiolitic” sequences. Our current research challenges this geodynamic scenario, requiring multiple tectonic events because of multiple metamorphic ages (Sm-Nd, U-Pb and Ar-Ar) and different PT paths recorded in the HP–LT rocks on either side of the MFS. However, the extant data are inadequate to substantiate a single, self-consistent geodynamic model for the GSZ. Therefore we are working in a research plan that integrate field studies with structural, petrological, geochemical and geochronological data to characterize more fully these paleo-subduction systems, focusing on the oceanic crust bodies. Through the proposed research, an enhanced understanding of major suture zones and their related ancient geodynamic processes should be forthcoming.
See Publications and Curriculum Vitae for all references cited above