Age of the Socorro Magma Body: Surface Uplift History from River Terrace Correlation and Cosmochronology

索科罗岩浆体是地球上已知最大的中地壳岩浆体之一：它是一个类似于冰碛的地貌，面积约3,400平方公里，厚度约150米，位于索科罗中央格兰德河裂谷下约19公里深的地方，新墨西哥州地区索科罗岩浆体引起地表隆起，最大速率约为2.5-3毫米/年，集中在主体的北方部分。地表隆起的模型，由于在19公里深的岩浆膨胀的弹性地壳响应，同意与干涉合成孔径雷达干涉图。岩浆体的年龄及其相关的地表隆起是有争议的。为了解决这一争议，新墨西哥州技术研究小组将对阶地遗迹进行试点研究，以确定地表隆起开始的年龄。他们将借助数字高程模型绘制阶地遗迹图，并利用土壤特性（粘土和碳酸盐含量）、地貌特性（表面纹理、沙漠清漆程度、阶地段内的位置）、阶地沉积物的沉积学特性（碎屑类型、沉积结构、粒度）和36 Cl年龄将其联系起来。保存完好和未改变的表面将使用36 Cl宇宙成因同位素剖面测年。阶地高程和垂直阶地间距的横向变化，反过来，将允许识别受索科罗岩浆体膨胀影响或不受影响的阶地。阶地年龄将包括与索科罗岩浆体相关的抬升的开始，并限制长期的抬升和岩浆体膨胀速率。索科罗岩浆体是地球上已知的最大的中地壳岩浆体之一。水准测量和干涉合成孔径雷达研究表明，岩浆体正在以大约2.5毫米/年的速度（在隆起最快的中心区域）引起地表隆起。索科罗地震异常区位于岩浆体之上，是新墨西哥州上地壳地震活动率最高的地区。微震活动可能是由索科罗岩浆体上方的变形和上升的含水流体触发的。该项目旨在限制Socorro岩浆体的年龄，这与理解地壳流变学，脆韧性转变的演变，裂谷中的地壳生长，裂谷过程中的岩浆成因，裂谷过程中的应力演化和火山灾害有关。

The Socorro magma body is one of the largest known midcrustal magma bodies on Earth: it is a sill-like feature, about 3,400 square kilometers in area, about 150 meters thick, and lies at about 19 km depth under the central Rio Grande rift in the Socorro, New Mexico area The Socorro magma body causes surface uplift with a maximum rate of about 2.5-3 mm/yr centered over the northern part of the body. Models of surface uplift due to an elastic crustal response to magmatic inflation at 19 km depth agree well with InSAR interferograms. The age of the magma body and its related surface uplift are controversial. In order to resolve this controversy, the New Mexico Tech research team will carry out a pilot study of terrace remnants to determine the age of onset of surface uplift. They will map the terrace remnants with the aid of Digital Elevation Models and correlate them using soil characteristics (clay and carbonate content), geomorphic characteristics (surface textures, degree of desert varnish, location within flights of terraces), sedimentological characteristics of terrace deposits (clast types, sedimentary structures, grain size), and 36Cl ages. Well-preserved and unaltered surfaces will be dated using 36Cl cosmogenic isotope profile dating. Lateral changes in terrace elevations and vertical terrace spacing will, in turn, allow identification of those terraces affected or unaffected by Socorro magma body inflation. Terrace ages will bracket onset of Socorro magma body -related uplift and constrain long-term rates of uplift and magma-body inflation.The Socorro magma body is one of the largest known midcrustal magma bodies on Earth. Leveling and InSAR studies indicate that the magma body is causing surface uplift at rates of about 2.5 mm/yr (in the central zone of fastest uplift). The Socorro Seismic Anomaly has the highest rate of upper crustal seismicity in New Mexico and lies above the magma body. Microseismicity presumably is triggered by deformation and ascending hydrous fluids above the Socorro magma body. This project seeks to constrain the age of the Socorro magma body, which is relevant to understanding crustal rheology, evolution of the brittle-ductile transition, crustal growth in rifts, magma genesis during rifting, stress evolution during rifting, and volcanic hazard.