Publications

During the burial of mudstones, the associated organic matter undergoes gradual thermal maturation, a key process that can influence the reactivity of organic matter during catagenesis, the formation of hydrocarbon deposits and the chemical weathering of mudstones. Conventional methods for assessing the thermal maturity of organic matter often fail to reflect the geochemical...

No abstract available.

Correlations between grade and tonnage exist in mineral resource data compiled from published reports, but they are not always addressed during quantitative assessment of undiscovered mineral resources. Failure to account for correlated grade and tonnage distributions can result in geologically unrealistic assessment results. Current software tools simulate univariate ore tonnage and...

Critical minerals are commodities essential to modern industrial and strategic technologies and are highly vulnerable to supply chain disruption. The Critical Minerals Mapping Initiative (CMMI) is a collaboration among the U.S. Geological Survey (USGS), the Geological Survey of Canada, and Geoscience Australia that aims to deepen global understanding of where critical minerals are...

The Upper Cretaceous Tuscaloosa marine shale (TMS) potential production area encompasses 20.4 million acres across central Louisiana (LA), southern Mississippi (MS), southwestern Alabama (AL), and a small southwestern section of the Florida panhandle (Hackley et al., 2018). It remains a minor and largely undeveloped unconventional shale oil play with production from the TMS confined...

A new quantitative mineral resource assessment for tungsten skarn was conducted for the Auminzatau and Kuldjuktau mountain ranges in Central Uzbekistan, along with qualitative assessments of orogenic gold, rare earth elements (REEs), amorphous graphite, and uranium. By integrating a variety of geological, geochemical, geophysical, and remote sensing data sets, estimates of undiscovered...

Natural radiogenic isotopes (primarily 87Sr/86Sr) from hot springs in the Upper Geyser Basin of the Yellowstone Plateau volcanic field and associated rocks were used to evaluate groundwater flow patterns, water-rock reactions, and the extent of mixing between various groundwater sources. Thermal waters have very low uranium concentrations and 234U/238U activity ratios near 1.0, which...

High-grade ores in low-sulfidation epithermal deposits commonly consist of banded veins containing quartz as the most abundant gangue mineral. Previous studies suggested that at least some of the quartz has formed as a product of recrystallization from a noncrystalline silica precursor. Detailed petrographic studies confirm that high-grade veins from the

No abstract available.

The ca. 2737 Ma (Souders, 2023) Mentor anorthosite intrusive complex (MAIC) lies near the northern margin of the Wawa subprovince of the Archean Superior Province, in an area of northwestern Minnesota where the Wawa, Quetico, and Wabigoon subprovinces are juxtaposed in close proximity (Fig. 1). The rocks of interest are entirely concealed by 10s to >100 m of unconsolidated Quaternary...

The Basin and Range province of North America hosts substantial lacustrine evaporite mineral systems prospective for lithium, a critical mineral currently listed for mineral resource assessment by the U.S. Geological Survey. Airborne electromagnetic (AEM) surveys are being conducted to support these assessments by identifying shallow clays and brines, as well as through improving the...