Grappling with systemic discrimination and bias in geosciences can be overwhelming to the point that one may feel powerless to fix them. Despite the sweeping nature of this challenge, faculty, principal investigators, and other scientists with leadership roles have unparalleled power to mitigate harm in environments they oversee. Here, we identify ways that scientists in these roles can immediately address bias in three common spaces --- the lab, field, and classroom. We highlight key actions that can be taken to improve the quality of life of marginalized students and other trainees quickly, while important but comparatively slow institutional changes proceed.

Exhumation in continental and oceanic arc settings is linked to tectonic and climatic forces that result in some of the highest topography and erosion rates in the world. Regional exhumation studies of oceanic arcs are sparse due to poor exposure, accessibility, complex inherited structures, and thermal overprinting due to magmatism, reburial, and metamorphism. In contrast, the Aleutian arc has an unusually thick crust, exceptional subaerial exposure of plutons, and limited regional thermal overprinting, providing the ideal conditions for a systematic thermochronology study that investigates the mechanisms that lead to arc exhumation. By analyzing multiple chronometers (apatite and zircon (U-Th)/He, zircon U-Pb) with different temperature sensitivities within the same plutonic sample, we can constrain uplift and erosion rates over ~40 million years of Aleutian arc history. Here, we present preliminary apatite and zircon (U-Th)/He ages from 23 plutonic samples from the islands of Unalaska, Umnak, Atka, Ilak, and Amatignak. These data are part of a larger study where we will analyze a total of 78 samples collected from 11 plutons along >1400 km of the Central Aleutian Islands. Ultimately, this dataset will provide a regional framework to quantitatively assess the various proposed mechanisms for Aleutian arc exhumation, such as; 10° Pacific plate rotation, subduction of the Kula ridge, and/or pluton emplacement, each of which has predictable and testable geographic age trends. The samples analyzed are from plutons that crystallized in the Oligocene to Miocene based on zircon U-Pb dating. Both zircon and apatite (U-Th)/He ages also show an Oligocene to Miocene spread, with a majority of the ages from both chronometers pooling at 7-13 Ma and no particular geographic trend. These preliminary results suggest that a significant exhumation event occurred in the late Miocene, as has been observed in other circum-Pacific arcs. These preliminary data may support the hypothesis that the late Miocene pulse of high plutonism in the Aleutian Islands led to arc exhumation. However, additional samples need to be analyzed to provide an arc-scale view of exhumation timing, trends, and rates of the Central Aleutian arc in order to test possible uplift and erosion scenarios.

The 17th International Conference on Thermochronology (Thermo2021) was held in Santa Fe, New Mexico, on September 12-17, 2021. This bi-annual conference series evolved via the coalescence of the International Workshops on Fission Track Thermochronology, held since 1978, and the European Workshops on Thermochronology. It has become the premier forum for thermochronology practitioners and users to discuss fundamental and methodological topics and opportunities related to their science and its future. Each conference is independently organized, and a Standing Committee consisting of past organizers and other community members helps to ensure their continuation into the future. Thermo2021 was greatly affected by the COVID-19 pandemic. Normally the meeting would have been expected to draw ~250 attendees, but travel restrictions limited in-person attendance to 86, plus 21 remote presenters. Nearly all in-person participants were from the US, and only four were international. Talks and posters were distributed among five themes: (U-Th)/He; fission track; other thermochronometers; frontiers in data handling, statistics, interpretation methods, and modeling; and integration and interpretation. Although COVID-19 presented many challenges, it also allowed the Organizing Committee to adapt creatively and transform adversity into opportunity. In particular, the smaller number of attendees permitted more talks by students and early-career scientists, both within the theme sessions and in the Charles & Nancy Naeser Early Career Session. Discussion time was prioritized: at a Tuesday evening “swap meet” for ideas, in 30-40-minute time slots within each theme session, and in Friday afternoon breakouts for the first four themes and another dedicated to early career and DEI issues. These were used to identify emergent ideas and concerns across a broad range of topics, from the theory and practice of the various thermochronometric techniques, to their interpretation through thermal history modeling and other methods, to anticipated trends in data dissemination and management, to the needs of the next generation of thermochronologists, particularly in the US. Each Friday breakout designated a scribe who recorded the discussion and distributed their notes. Each group then designated one or more writers to transform the notes into text for this White Paper. Notes or early write-up versions were provided to the international thermochronology community, and feedback solicited. In addition, cross-cutting themes that occurred across multiple breakout groups were identified and compiled. This White Paper is the outcome of these efforts. We hope that it will serve as a record for the meeting, and an overview of where the predominantly US-based component of the thermochronology community considers the current state of knowledge to be and where future efforts should be directed, for developing both the science and its human infrastructure.