Goals (and conclusions) 1. Summarize the evolution of the Laurentian craton: segmented and heterogeneous nature of the lithosphere the need for 4-D integrated studies within EarthScope. 2. Summarize results from the CD-ROM experiment: pose alternative hypotheses for reddite and blueite the need for 3-D deployments of the flexible array. 3. Summarize the Southwestern U.S. EarthScope “superexperiment” proposal: a new paradigm for integrated and inclusive regional experiments within EarthScope. 4. Muse about the best targets for a Northern Rockies “Superexperiment”: towards a single integrated EarthScope experiment in the northern Rocky Mountains.

History and structure of the Wyoming Archean province– oldest parts of North American lithosphere secular change in lithospheric processes?

Extent of ~ 2.0 Ga Paleoproterozoic juvenile crust? Nature of Paleoproterozoic rifting in creating long-lived lithospheric boundaries

Great Falls Tectonic Zone and Vulcan Structure as parts of the greater Trans-Hudson:~1.9-1.8 Ga continent- continent collisions; “birth” of Laurentia

Extent of Trans-Hudson age tectonism beneath Proterozoic accreted terranes

Yavapai and Mojave provinces: interaction of collisional and accretionary orogens ~1.8 -1.7 Ga

Figure 3

Quartzite-rhyolite successions occur late in Yavapai orogeny

includes the Labradorian province Mazatzal province: ~1.65 Ga juvenile crust, includes the Labradorian province

stitch pre-1.65 Ga accreted crust ~1.65 Ga Mazatzal plutons stitch pre-1.65 Ga accreted crust

1.45-1.35 Ga Belt Basin related to accretion in south??

Grenville orogenic cycle, Assembly of Rodinia: 1.3-1.0 juvenile crust accreted during the Grenville orogenic cycle,

Grenville-aged extension & widespread normal faulting 1.1 Ga Midcontinent and related rifts: mafic dike swarms, Grenville-aged extension & widespread normal faulting

Western margin of Laurentia formed via 780-685 Ma breakup of Rodinia, Gunbarrel Dikes & Windermere Supergroup

Long-lived accretionary plate margin in southern Laurentia: 1800 - 1000 Ma

The nature and origin of mantle heterogeneity– a problem best solved in the Rockies CD-ROM RISTRA

Figure 3

Body Wave Tomography: RISTRA Small-scale convection?

Comparing CD-ROM and RISTRA: anomalies align along Precambrian structures? The need for 3-D

EarthScope Southwestern U.S. Superexperiment: Diverse tectonic elements in the Southwest require a 3-D seismic experiment integrated with geology

EarthScope Southwestern U.S. Superexperiment: Densification of Bigfoot (blue grid) to achieve 3-D resolution of regional tectonic provinces and 10-km-scale mantle velocity contrasts, and 4-D understanding of lithospheric evolution

MT images need to be integrated with seismic, geodetic, and geologic datasets

What is the extent to which topography is influenced by crustal versus mantle density variations and when and how did the density structure develop?

The nature and origin of mantle heterogeneity– a problem best solved in the Rockies CD-ROM RISTRA

Mantle to groundwater interconnections via analysis of deeply sourced CO2 springs containing mantle-derived helium

Conclusions The crust and upper mantle are segmented and highly heterogeneous and cannot be well understood without a 4-D integrated approach within EarthScope. There are two models to explain large velocity transitions (redite and blueite): 1) small scale asthenospheric convection, versus 2) preservation of old compositional provinces: We need 3-D deployments of the flexible array to resolve the relative importance of each model.

Goals and Conclusions 3. EarthScope needs to forge a new paradigm for large integated, collaborative, and inclusive regional experiments. 4. A Northern Rockies “Superexperiment”: could propose a single integrated experiment that addresses an integrated set of uniquely well-posed problems in the northern Rocky Mountains: Yellowstone, Archean Wyoming province, west edge of Laurentia, and neotectonics of the northern Rockies.