Miocene to Holocene Marine Tephrostratigraphy Offshore Northern Central America and Southern Mexico: Pulsed Activity of Known Volcanic Complexes

Abstract

We studied the tephra inventory of 14 deep sea drill sites of three Deep Sea Drilling Project and Ocean Drilling Program legs drilled offshore Guatemala and El Salvador (Legs 67, 84, and 138) and one leg offshore Mexico (Leg 66). Marine tephra layers reach back from the Miocene to the Holocene. We identified 223 primary ash beds and correlated these between the drill sites, with regions along the volcanic arcs, and to specific eruptions known from land. In total, 24 correlations were established between marine tephra layers and to well‐known Quaternary eruptions from El Salvador and Guatemala. Additional 25 tephra layers were correlated between marine sites. Another 108 single ash layers have been assigned to source areas on land resulting in a total of 157 single eruptive events. Tephra layer correlations to independently dated terrestrial deposits provide new time markers and help to improve or confirm age models of the respective drill sites. Applying the respective sedimentation rates derived from the age models, we calculated ages for all marine ash beds. Hence, we also obtained new age estimates for eight known but so far undated large terrestrial eruptions. Furthermore, this enables us to study the temporal evolution of explosive eruptions along the arc, and we discovered five pulses of increased activity: (1) a pulse during the Quaternary, (2) a Pliocene pulse between 6 and 3 Ma, (3) a Late Miocene pulse between 10 and 7 Ma, (4) a Middle Miocene pulse between 17 and 11 Ma, and (5) an Early Miocene pulse (ca. >21 Ma).

An integrated structural and GPS study of the Jalpatagua fault, southeastern Guatemala

“…Based on similarity coefficients and field evidence, sample 17JF23a from location 1 best correlates to the E tephra, a 51 ka tephra from the Amatitlan complex, and sample 17JF23b best correlates to the C tephra, a 54 ka tephra from a source near the Amatitlan caldera (Table 1; Fig. 2; Koch, 1970;McLean, 1970;Koch and McLean, 1975;Wunderman and Rose, 1984;Rose et al, 1987Rose et al, , 1999Schindlbeck et al, 2016). In the eastern section, the two tephra deposits collected from location 7 (samples WH19S1 and WH19S2; Table 1 the Moyuta volcano to the southwest of the outcrop, which is suggested to have output andesite and eruptive material during the Quaternary (Bethancourt et al, 1976).…”

“…The lithologies and timing of faulting also differed. Faulting at location 1 (north side) suggests that faulting occurred before deposition of tephra E (51 ka; Schindlbeck et al, 2016), after deposition of tephras E and C (54 ka), and before deposition of the most recent Amatitlan J tephras, which are unfaulted at location 1 (Fig. 3; Koch and McLean, 1975).…”

A history of violence: magma incubation, timing and tephra distribution of the Los Chocoyos supereruption (Atitlán Caldera, Guatemala)

“…During the estimated 20-27-day duration of the LCY climactic ultra-Plinian eruption (Ledbetter and Sparks, 1979), a >40-km-high eruptive column produced fall-out deposits up to 3.6 m thick in proximal locations, and distal cm-thick deposits spanning from the coast of Texas to the Panama Basin ( Fig. 1b; Drexler et al, 1980;Rose et al, 1987;Kutterolf et al, 2016;Schindlbeck et al, 2018). Concurrently, repeated gravitational collapse from the eruptive column produced voluminous PDCs that surmounted remarkably high topographic barriers in the Kutterolf et al (2016).…”

“…2), and~1 km 3 of surge deposits, which formed during late-stage phreatomagmatic explosions (Rose et al, 1987). Based on distal outcrops at Lake Petén Itzá and offshore data from the Pacific Ocean and the Caribbean Sea, current estimates on mass and tephra volume for the LCY eruption are~1.3 × 10 15 kg and~1100 km 3 (510 km 3 , dense rock equivalent, DRE), respectively (Kutterolf et al, 2016;Schindlbeck et al, 2018). The older W-Fall and younger I-Fall yield erupted tephra volumes of~83 km 3 (DRE) and~7 km 3 (DRE), respectively (Rose et al, 1987;Kutterolf et al, 2016).…”

Zircon and Melt Extraction From a Long‐Lived and Vertically Extensive Magma System Underneath Ilopango Caldera (El Salvador)

“…The TB suite comprises, from oldest to youngest, the TB4, TB3, TB2, and TBJ events, which tapped rhyolitic to dacitic magma (Hernández et al., 2010; Kutterolf et al., 2008a, 2008b; Pedrazzi et al., 2019). TBJ (∼106 km 3 ) and TB4 (∼36 km 3 ) stand out as the most voluminous eruptions among the TB suite, with deposits extending to the Pacific Ocean (Dull et al., 2019; Kutterolf et al., 2008; Mehringer et al., 2005; Schindlbeck et al., 2018). Although radioisotopic dates for TB4, TB2, and TB3 were lacking prior to this study, stratigraphic position implies an age of <57 ka for TB4 (Rose et al., 1999), whereas sedimentation rates suggest an apparent age of ca.…”