Collaborative Research: Reconstructions of the Gulf of California - Salton Trough Plate Boundary Since 14 Ma: A Digital Synthesis of Recent Advances and Outstanding Problems

PI将构建一系列基于地理信息系统的数字古构造和古地理地图，这些地图将以200万年的增量跟踪从14 Ma到现在的加利福尼亚州湾-索尔顿海槽板块边界的发展。将绘制一套从6 Ma到现在的地图--在这段时间内，相对板块运动的速度和板块边界偏移的总量得到了广泛的一致同意。将在14~6 Ma期间绘制两套地图，以突出两种截然不同的端员模式，以确定裂谷开始、海侵、横跨海湾的总偏移量和板块边界发育的运动学：(1)修正的应变分配模型，海侵约8 Ma进入南湾，约6 Ma进入北湾；(2)早至约12 Ma，未分割的、综合的区域应变与海侵。利用这一方法，投资促进机构将充分探索两个终端成员模型的众多影响和预测，并提出在未来研究中解决这一重大悬而未决的争议所需的新数据。这些重建将突出最近在理解方面的进展以及尚未解决的争议。他们希望，地图重建还将挑战研究界，为未来的工作制定严格的、可验证的假说，探索大陆裂谷的潜在过程、洋盆的诞生，以及走滑和/或伸展应变在调节这些过程中的可能作用。加州海湾-索尔顿海的这种合成是由边际审查小组/方案推荐的。合成的广泛影响代表着对更广泛的地球科学界的重要服务。它将加强研究和教育，并将向地球和环境科学讲师以及该区域潜在的生态旅游地点的公众开放。研究生将获得协作科学研究的经验，提高他们的地理信息系统技能，并总体上增加他们对焦点站点的知识。

The PIs will construct a series of digital GIS-based paleotectonic and paleogeographic maps that will track development of the Gulf of California - Salton Trough plate boundary in 2-million-year increments from 14 Ma to the present. One set of maps will be made for the period from 6 Ma to the present - a time for which the rate of relative plate motion and the total amount of plate-boundary offset are widely agreed upon. Two sets of maps will be developed for the period from 14 to 6 Ma to highlight two contrasting end-member models for the timing of rift initiation, marine incursion, total offset across the Gulf, and kinematics of plate boundary development: (1) modified strain-partitioning model, with marine incursion into the southern Gulf at ~8 Ma and into the northern Gulf at ~6 Ma; and (2) non-partitioned, integrated regional strain with marine incursion as early as ca. 12 Ma. Using this approach, the PIs will fully explore the numerous implications and predictions of the two end-member models and suggest new data that will be needed to address this major unresolved controversy in future studies. The reconstructions will highlight both recent advances in understanding as well as unresolved controversies. They hope that the map reconstructions will also challenge the research community to develop rigorous testable hypotheses for future work that will explore the underlying processes of continental rifting, birth of an ocean basin, and the possible role of strike-slip and/or transtensional strain in modulating those processes. This kind of synthesis of the Gulf of California-Salton Sea was recommended by the MARGINS review panels/program.Broader impacts of the synthesis represent an important service to a broader Earth science community. It will enhance both research and education and will be available for instructors in Earth and environmental sciences and to the general public for potential ecotourism sites in the region. Graduate students will gain experience with collaborative scientific research, improve their GIS skills, and increase their knowledge of the focus site in general.