Rapid vertical motions and formation of volcanic arc gaps: Plateau collision recorded in the forearc geological evolution (Costa Rica margin)

Abstract

The collision of bathymetric features with modern convergent margins has been investigated with the full range of tools used in geosciences. Hence, a comprehensive picture exists of the characteristic effects of collision events on the evolution of convergent margins. In contrast, much less studies documented past collisions of bathymetric features with convergent margins, as colliding features were generally lost to subduction. The arc-trench system of southern Central America provides modern and past textbook examples of active margin interaction with incoming bathymetric reliefs. Here, we propose a synthesis which combines basin and terrane analysis of the forearc of northern Costa Rica and takes up the challenge of documenting past episodes of plateau accretion to the active margin. As illustrated in modern examples, our study shows that kilometric uplift of the overriding plate and termination of the volcanic arc activity are the most profound effects of colliding/accreting oceanic plateaus. Kilometric uplift of the forearc is documented by short-lived (ca. 3 m.y.) occurrences of shallow-water deposits in an overall deep-water forearc record. These shallow deposits contain material reworked from underlying sedimentary and basement lithologies. The development of spatial gaps in arc volcanism is deduced from the transition from arcderived turbidites to pelagic sediments. Eventually, end of the collision event is evidenced by the subsidence of the whole forearc to deep-water environments.Basin subsidence is accompanied or followed by renewed volcanic arc activity and coeval arc-derived sedimentation, which may occur 1-7 m.y. after plateau collision. These past episodes of plateau accretion are archetypal for the following reasons: (a) they may be studied in outcrop, whereas most of the modern collisions of plateaus largely occur underwater; (b) no tectonic or metamorphic imprint has significantly complicated the forearc geological record; (c) the colliding feature and the sedimentary response to its collision are both preserved in the forearc geology; (d) they may be used as analogues for any setting where a bathymetric feature is suspected to have caused rapid forearc uplift and cessation of the volcanic arc activity.---

Cenozoic Stages of Forearc Evolution Following the Accretion of a Sliver From the Late Cretaceous‐Caribbean Large Igneous Province: SW Ecuador‐NW Peru

“…The sedimentary record can provide valuable information about past episodes, but the information may be biased by the better preserved geological evidence (Draut & Clift, ). Ancient forearc regions are commonly composed of amalgamations of continental fragments, intra‐oceanic island arcs, or the entrapment of oceanic plateau slivers (e.g., Costa Rica margin, Andjić et al, ; Great basin, Dickinson, ; NW South America, Kerr & Tarney, ), making it imperative to account for their role in the tectonostratigraphic evolution of forearc basins.…”

Paleomagnetism and Geochronology of the Early Cretaceous Dipilto Batholith (NW Nicaragua): Chortís Block Large Rotation With Respect to SW North America

“…Several reviews of Mexican tectono-stratigraphic terranes and complexes include Campa and Coney (1983), Keppie (2004), Ortega-Gutiérrez et al (2018), and Sedlock et al (1993). Since Early Cretaceous time the Chortís block has interacted with the following terranes and complexes ( Figure 1a): (1) Oaxaca, with Grenville (1300-990 Ma) basement consisting mainly of granulite facies (Solari et al, 2003, and others); (2) Mixteco, with a Paleozoic polymetamorphic basement, comprising diverse metamorphic and igneous suites of Ordovician to Early Triassic ages (Ortega-Gutiérrez et al, 1999; and others); (3) Juárez, consisting of a Mesozoic sequence of low to medium-grade phyllites and schist, and some MORB Andjić et al, 2018;Campa & Coney, 1983;Centeno-García, 2017;Fitz-Díaz et al, 2018;Flores et al, 2015;Sedlock et al, 1993). In dotted lines, the classical models that position the Chortís block juxtaposed south of Mexico (x) and with a separation angle (y) Rogers, Mann, Scott, & Patino, 2007).…”

“…The Caribbean plate is a combination of oceanic fragments divided into four oceanic plateau provinces: (1) the Late Triassic to Late Cretaceous Siuna Terrane of oceanic crust affinity (Venable, 1994), also known as the Mesquito Composite Oceanic Terranes (MCOT; Baumgartner et al, 2008); (2) the Early Cretaceous accreted intra-oceanic arc and seamount Santa Elena and Nicoya Complexes (Baumgartner & Denyer, 2006;Escuder-Viruete et al, 2015;Hauff et al, 2000); (3) the Early Cretaceous igneous plateau Manzanillo Terrane (Andjić et al, 2018); and (4) the Late Cretaceous Caribbean Large Igneous Province (Hoernle et al, 2004). Of these, the terrane most related to the Chortís block is the Siuna Terrane-MCOT that probably collided along the southern part of the Chortís block in the Late Cretaceous (Figure 1; Baumgartner et al, 2008;Rogers, Mann, Emmet, & Venable, 2007;Sanchez et al, 2016).…”

“…(a) Tectonic and geological frameworks of southwestern Mexico and Central America (based on Andjić et al, ; Campa & Coney, ; Centeno‐García, ; Fitz‐Díaz et al, ; Flores et al, ; Rogers, Mann, & Emmet, ; Sedlock et al, ). In dotted lines, the classical models that position the Chortís block juxtaposed south of Mexico ( x ) and with a separation angle ( y ) (Molina‐Garza et al, ; Rogers, Mann, Scott, & Patino, ).…”

“…In dotted lines, the classical models that position the Chortís block juxtaposed south of Mexico ( x ) and with a separation angle ( y ) (Molina‐Garza et al, ; Rogers, Mann, Scott, & Patino, ). (b) Tectonic map and geological units of northern Central America, as well as the geophysical boundary of Chortís block (based on Andjić et al, ; Lücke, ; Ott, ; Rogers, Mann, & Emmet, ; Sanchez et al, , ). The gray isolines are the Moho depth in kilometers (Lücke, ).…”