Geomorphology in action! Sinkhole, anyone? A startling site while hiking out on the mesa grasslands, even for this lifelong CA coastal hiker and geologic explorer. I have never seen a seepage-cut depression this large and deep; cut down through the bedrock; this far from the shoreline; and apparently not influenced by human drainage/irrigation debacles. Surging, … More Spring Ranch: Sinkholes, Emergent Tectonics, and Mini Terraces

Marine terraces are a defining geomorphological feature of the West Coast, and are dispersed along the entire extent of California’s active, uplifting coastline. Found on emergent tectonic coastal margins worldwide, marine terraces underlay much of California’s heavily developed and populated regions.  Terrace Geomorphology: Tectonics and Sea Level Change Marine terraces begin as wave cut platforms, … More California’s Marine Terraces

Blizzards are rare in California, and when they do occur it is usually in the higher alpine zones of the Sierra-Nevada and southern Cascade Range, where they can be hard to detect or predict. Technically, a blizzard is a severe storm characterized by high winds and reduced visibilities due to falling or blowing snow. The … More California’s Historic Blizzards

Geology and Geomorphology of the Rancho La Brea Tar Pits On the chronostratigraphic scale of geologic time, a picture of earth’s past structures, systems, and inhabitants increasingly comes into focus as the ascent out of deep time accelerates toward our current moment on the planet. Geochronologic divisions of life and physical events on earth (based … More Geology and Geomorphology of the Rancho La Brea Tar Pits

Serpentinite in California The State rock of California, commonly referred to as Serpentine, is known for its striking blue-green hue, slick surfaces, and dramatic topography. Serpentinite landscapes form California’s emblematic towering coastal cliffs, Sierran talus slopes, and the pastoral rolling hills of Franciscan formation and Franciscan mélange in the Coast Ranges. What Prominent in California, … More Serpentinite in California

Geomorphology of California’s Seasonal Freshwater Wetlands For the purpose of this research, and to get a better understanding of this overwhelming and ecologically vital topic, I have grouped California’s seasonal (vernal, ephemeral) freshwater wetlands into four categories, or associations, based on broad geomorphological distinctions, and differing hydrologic characteristics: coastal seasonal freshwater meadows; valley hardpan vernal … More Geomorphology of California’s Seasonal Freshwater Wetlands

Landslides and Mass Movement in California Once again, California has awoken from a multi-year drought of increasing intensity to an inordinately wet and stormy winter. It may be an early and truncated rainy season, but the return of incessant precipitation and the sound of downpours and gusting south winds is an old familiar friend to … More Landslides and Mass Movement in California

Dr. Tanya Atwater Who has heard of Dr. Tanya Atwater in their geology class, or plate tectonics theory class, or on the news every time there is an earthquake in California? Not me. That’s mostly due to the ongoing legacy of sexism in science, and partly because the Geological Society of America is controlling most … More Community Profile – Dr. Tanya Atwater

The San Andreas Fault System, Bay Area Fault Complex, and the Mount Tamalpais Blind Thrust The San Andreas Fault is not only in constant motion it is also constantly evolving, expanding, and adjusting its course. With monumental reverberations of give and take, the greater San Andreas Fault system produces an ever-shifting network of compressional and … More The San Andreas Fault System, Bay Area Fault Complex, and the Mount Tamalpais Blind Thrust

California’s Geologic Building Blocks, and the Accretionary Wedge I have been looking forward to researching and writing about accretionary wedge formation and theory for a while – it’s an exciting geologic phenomenon of tectonics which underlies much of western California. But I soon realized that this one element of our subduction complex geomorphology could not … More California’s Geologic Building Blocks, and the Accretionary Wedge