Scientific Webinars

The Cambrian Explosion marks the rise of diverse animal groups ca. 540 million years ago, but the triggers for this revolution remain poorly understood. The roots of the Cambrian Explosion are in to be found in the preceding Ediacaran, and we can now document a series of pulses of enhanced seawater oxygen stability over the Ediacaran to Cambrian interval. These coincide with pulses of diversification and increased body size in animals, and the biological control of carbonate production was driven by the rise of predation.

Human energy expenditure in the Anthropocene (starting ~1950CE) is ~22 zetajoules (ZJ), and exceeds all human energy expended across the prior 11,700 years of the Holocene (at ~14.6 ZJ), largely through the combustion of fossil fuels. The global warming effect during the Anthropocene is more than an order of magnitude greater still. Global human population and their productivity and energy consumption are highly correlated and with most changes impacting the global environment: number of large dams; shrimp farming; industrial production of plastic, cement, ammonia, copper, gypsum, salt, iron, steel, sulfur, helium, aluminum; mineral species; atmospheric gases (CO2, N2O, CH4); terrestrial freshwater budgets; and surface temperatures, sea levels, and ice masses. This extraordinary outburst of energy and productivity demonstrates how it is that the Earth System in the past 70 years has departed from its Holocene state, forcing abrupt physical, chemical and biological changes to the Earth’s stratigraphic record that can be used to justify the proposal for naming a new epoch – the Anthropocene.

Aggradational bedforms, from dunes to cyclic steps, are the subject of dozens of papers each year, producing lots of startling discoveries. These bedforms tell us about the flows that formed them and in turn aid interpretation and prediction. In contrast, sole structures have been almost entirely neglected for 50 years; unloved, ignored, and whose only role is to tell geologists which way the flow went. Here we present a new process model of flutes and tool marks in deep-marine environments that tackles a host of long-standing conundrums, and examines under what flow types these structures form. We finish by looking at the implications of the work including a revised Bouma Sequence diagram.

A Virtual Outcrop (VO) is a 3D photorealistic model of a cliff or quarry that captures the geological features. Most recently, model sharing across the web has become possible through generic sharing sites such as Sketchfab and purpose-built sites like V3Geo.com. In this presentation we review the history for virtual outcrops and briefly discuss how they are collected, processed and how to access data that is available for public usage. We will then take a short virtual fieldtrip to the Book Cliffs of Eastern Utah, primarily to illustrate some of our learnings on the topic. We will conclude with a short discussion on the mechanics of how to build a VFT using publicly available data in LIME.

Bedforms are a key tool to reconstruct sedimentary processes in modern and ancient environments. This talk will present novel mixed sand-mud bedforms which have different shapes and sizes compared to pure-sand bedforms, and are found in the fringe of submarine fans. These striking mixed sand-mud bedforms are interpreted to be produced by sediment gravity flows with transient-turbulent fluid dynamics, due to the presence of cohesive clay. The presence and spatial trends in mixed sand–mud bedform types may be an important tool in interpreting fan fringe environments.

Join us as we explore the diverse world of Sedimentology. Drawing from a tranche of past BSRG talks and more, examples will be presented of sedimentary structures in ice and snow, the desert, the sky as well as more conventional settings. Prepare to be baffled by some real head scratchers and wowed by some of Earth’s largest ever structures, and finally head into space to speculate on the sedimentology of exoplanets.

Kathleen is a science team member for Mars 2020, This talk will give an overview of halite and gypsum on Mars and describe their potential to host microorganisms and organic compounds as solid inclusions and within fluid inclusions – as salt minerals on Earth do. The talk will place the search for life in salt minerals on Mars in context of the sample return plan for the Perseverance rover.

In the present day, Mars’ mid-to-high latitudes host abundant water ice within diverse and stunning glacial landscapes. In this talk, I will explore the recent history of glaciation and glacial meltwater on Mars, and discuss some of the morphological mysteries that remain.

During the webinar we shall report our recent studies to survey and sample the ultra-deep water hadal trenches that allow an unravelling the earthquake history of subduction zones and provide new insight into sediment mass and carbon transfer into the hadal trench – one of the least-explored sedimentary environments on our planet.

Strata may contain a signal that records the history of the tectonic and climatic forcing that controls how they form, and many conceptual models tie themselves in logical knots by assuming that these signals are always present in the strata. More interesting than assuming that a signal is present is testing what the signal might look like if it was present, and exploring how it can be extracted from the noise and autogenic patterns that may also be present. This presentation will show some results from numerical experiments using Lobyte3D, a simple stratigraphic forward model of a deep-water fan system, to investigate how an external signal is recorded, and how it can be distinguished, or not, from the autogenic patterns also present in the strata.