Beveling the Colorado Plateau: Early Mesozoic Rift‐Related Flexure Explains Erosion and Anomalous Deposition in the Southern Cordilleran Foreland Basin

Deposition of the Late Jurassic Morrison Formation in a back-bulge depozone and formation of the overlying sub-Cretaceous unconformity above a forebulge mark the birth of the foreland basin system in the central U.S. Cordillera. In the southern U.S. Cordillera, the Morrison Formation is either anomalously thick or absent and the sub-Cretaceous unconformity cuts out progressively older stratigraphy toward the south on the Colorado Plateau. Based on results of 2D and 3D flexural modeling, we suggest that flexural uplift of the northern rift flank of the Bisbee segment of the Borderland Rift Belt can explain these observations. Structural restoration of the sub-Cretaceous unconformity indicates a minimum of 1.5 km of uplift and flexural models with an effective elastic thickness of 55 ± 5 km can reproduce the geometry of the unconformity and rift flank. This implies that effective elastic thickness has decreased between the Jurassic and the present, consistent with hypotheses for uplift and modification of the Colorado Plateau lithosphere during the Late Mesozoic to Cenozoic. Modeling results also predict the presence of a rift-related flexural trough in the Four Corners region of the Colorado Plateau, which may explain above-average thickness of the Morrison Formation. Constructive interference between a flexural back-bulge depozone and a flexural rift-flank trough may help explain anomalously high Late Jurassic subsidence. © 2021. American Geophysical Union. All Rights Reserved.6 month embargo; first published: 25 May 2021This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Thermochronological and Geochronological Constraints on Late Cretaceous Unroofing and Proximal Sedimentation in the Sevier Orogenic Belt, Utah

A source-to-sink analysis incorporating geochronometric and thermochronometric data from the Sevier fold-thrust belt (SFTB) and proximal synorogenic strata of the Canyon Range Conglomerate (CRC) and Indianola Group (IG) provides new insights into orogenic exhumation, erosional unroofing, and the interplay between thrusting and coarse clastic deposition in the Cretaceous Cordilleran foreland basin of western North America. Zircon (U-Th)/He ages from the Pavant and Nebo thrust sheets record significant Cenomanian cooling indicative of synchronous exhumation and thrusting along a large segment of the SFTB in central and northern Utah. Detrital zircon (U-Th)/He (DZHe) ages indistinguishable from depositional ages from the Cenomanian Dakota Formation and lower CRC also record rapid unroofing of the SFTB and synchronous deposition. DZHe data from wedge-top deposits of the CRC record two significant unroofing episodes: Albo-Cenomanian exhumation of the Pavant thrust and progressive unroofing of the Canyon Range culmination. For the IG, the presence of Paleozoic DZHe ages along with Paleozoic-Mesozoic DZ U-Pb ages in the Cenomanian Sanpete Formation suggests derivation from Paleozoic to Jurassic strata exhumed in the frontal Pavant and Nebo thrust sheets. After the Cenomanian episode of rapid exhumation, proximal foredeep strata recorded a widespread DZ provenance shift in the Turonian. Short DZHe lag time values from Campanian CRC and IG deposits reveal rapid exhumation of the SFTB during the Campanian. The synchroneity of major shortening and Campanian and Cenomanian changes in foreland basin architecture and provenance supports models proposing that active shortening in the fold-thrust belt coincides with coarse clastic influx in foreland basins.6 month embargo; first published: 23 May 2020This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Cyber Conflicts in International Relations: Framework and Case Studies

Although cyber conflict is no longer considered particularly unusual, significant uncertainties remain about the nature, scale, scope and other critical features of it. This study addresses a subset of these issues by developing an internally consistent framework and applying it to a series of 17 case studies. We present each case in terms of (a) its socio-political context, (b) technical features, (c) the outcome and inferences drawn in the sources examined. The profile of each case includes the actors, their actions, tools they used and power relationships, and the outcomes with inferences or observations. Our findings include: • Cyberspace has brought in a number of new players – activists, shady government contractors – to international conflict, and traditional actors (notably states) have increasingly recognized the importance of the domain. • The involvement of the private sector on cybersecurity (“cyber defense”) has been critical: 16 out of the 17 cases studied involved the private sector either in attack or defense. • All of the major international cyber conflicts presented here have been related to an ongoing conflict (“attack” or “war”) in the physical domain. • Rich industrialized countries with a highly developed ICT infrastructure are at a higher risk concerning cyber attacks. • Distributed Denial of Service (DDoS) is by far the most common type of cyber attack. • Air-gapped (not connected to the public Internet) networks have not been exempt from attacks. • A perpetrator does not need highly specialized technical knowledge to intrude computer networks. • The potential damage of a cyber strike is likely to continue increasing as the Internet expands. • The size of the actor under attack could have an influence on its ability to deter the attackers with actions in the physical world. • The entrance barriers (including the monetary cost) for any actor to get involved in a conflict seem to be much lower in the cyber domain than in the physical domain. • Accountability on the Internet is difficult, and gets further obscured when the attacks transcend national borders. This fact has probably made cyber attacks desirable for major military powers such as China, Russia and the United States. In many ways, this paper is a re-analysis of the case studies set presented on A Fierce Domain: Conflict in Cyberspace, 1986 to 2012 recently published by the Atlantic Council. In addition, we draw upon other materials (academic and media) to expand our understanding of each case, and add several cases to the original collection resulting in a data set of 17 cyber conflict, spanning almost three decades (1985-2013). Cuckoo's Egg, Morris Worm, Solar Sunrise, Electronic Disturbance Theater, ILOVEYOU, Chinese Espionage, Estonia, Russo-Georgian war, Conficker, NSA-Snowden, WikiLeaks and Stuxnet are some of the major cases included.This material is based on work supported by the U.S. Office of Naval Research, Grant No. N00014-09-1-0597. Any opinions, findings, conclusions or recommendations therein are those of the author(s) and do not necessarily reflect the views of the Office of Naval Research