The Enigma of the Soil: A Geological Odyssey
Understanding the Terrain: Soil Types and Characteristics
What you need for this EarthCache:
• Water for estimating sand and clay content. This is probably best done on a non-rainy day.
• Please remember to practice Leave No Trace ethics to preserve this experience and environment for future visitors:
• Hiking off-trail is not required at this EarthCache.
Email the following answers to us, but do not place the answers in your log please. Include the GC code
1. What is the primary soil texture found in the Bradwell soils, and how does it differ from the Asquith soils?
2. What were the results of your field test to determine if the soil at this site is sandy, loamy, or clayey?
3. What are the definitions of the scientific terms ‘fluvial’ and ‘lacustrine’ in the context of soil formation?
4. Post a photo of yourself or group or pet (or your GPSr or your name tag) at one of the waypoints that clearly shows that you were there at the time of logging.
DO NOT POST ANSWERS IN YOUR LOG. Please don’t provide the answers in when logging the cache online, but use “Send answers” feature. Please remember to answer to the best of your ability. As long as you give it your best effort, we'll be happy to accept your responses. Except for the field test #2, you will probably the answers you are looking for in this description page!
Optional:
Adventure to a way point for a more thorough exploration of GZ
In the heart of the vast prairies, where the undulating landscape weaves a tapestry of ancient whispers and geological secrets, the soil holds more than mere sustenance; it is a living chronicle of millennia past. Here, in the sprawling canvas of Saskatchewan’s Bradwell soils, the earth reveals its layered history through a geological symphony.
A Dance of Ice and Water: The Origins
Eons ago, the landscape was sculpted by titanic glaciers that wandered over the land like colossal, icy giants. These glaciers, with their relentless advance and retreat, laid down the foundational materials for the soil we see today. This process of glacial sculpting left behind a mosaic of geological deposits, each narrating a distinct chapter of Earth's history.
Glacial till—a term used to describe the unsorted material deposited directly by glaciers—formed the foundational layer of the soil. This till, a jumble of boulders, gravels, sands, and clays, was the initial canvas upon which subsequent geological processes would paint. As the glaciers retreated, they left behind a rough, mixed texture, often referred to as a "glacial drift." This chaotic mixture laid the groundwork for the varied soil textures found today, including the loamy and sandy components of modern soils.
Yet, the story did not end with the melting of the ice. As the glaciers withdrew, their melting waters carved new pathways, forming rivers and lakes. This gave rise to glacio-fluvial deposits—materials laid down by the swift waters flowing from melting ice, characterized by well-sorted sands and gravels. Similarly, glacio-lacustrine deposits settled in the still waters of glacial lakes, where fine sediments like silts and clays accumulated, creating a more sorted and homogeneous layer.
Among the diverse deposits, the ground moraine stands out as the most abundant in the area. This deposit is a chaotic mixture of soil and rock, laid down beneath the glacier and left behind as a morass of till, marking the glacier’s former reach. It is followed in abundance by spillway deposits, which come in two types: (a) thick deposits of sand and sand and gravel that overlay till or bedrock, and (b) very thin deposits of sand and gravel that lie directly over bedrock. These spillway deposits often mark the paths of ancient meltwater streams that once coursed through the glacial landscape.
The narrative continues with outwash deposits, which are the remnants of glacial meltwater that carried away and deposited materials like sands and gravels in broad, fan-shaped features. Kames, distinct hills or mounds formed by sediment accumulation in crevices of retreating glaciers, add another layer of complexity to the geological tapestry.
During the deglaciation of the Cory Plains district, including the Yorath Island Spillway and the parallel Moon Lake Spillway, a dramatic transformation occurred. Glacial meltwaters surged, carving out and collecting in what became the Glacial Saskatoon Lake Basin. As the ice retreated to the north and east of the Cory Plains, these meltwaters flowed through the spillways—most notably the Moon Lake Spillway and Yorath Island Spillway—or gathered in minor lakes, wetlands, and marsh basins. These bodies of water, along the Cory Plains between the Glacial North Saskatchewan River and the Glacial South Saskatchewan Lake, formed a complex network across the Cory Plains. The legacy of these ancient spillways and basins is still evident today, visible in satellite imagery as yet distinct, traces of wetland basins which were once-mighty watercourses.
The Soil of the Bradwell Association: A Geological Tale
As we turn our gaze to the present, the soils of the Bradwell Association unfold their narrative. The Bradwell soils have their genesis in glacio-lacustrine deposits. These soils emerged from the sediments left by ancient glacial lakes, characterized by a loamy texture with varying degrees of clay content. The Bradwell (Br) soil association, particularly the Br3 map unit, showcases this legacy. The Bradwell Association includes a set of Chernozemic Dark Brown soils that developed under grassland vegetation. These soils originated from glacio-lacustrine deposits, which are sandy, medium to moderately fine-textured, and moderately calcareous. Asquith soils tend to have a lighter, sandier texture compared to the loamier Bradwell soils. In this area have been found lacustrine Bradwell Association, fluvial Asquith, and the alluvial Meadow Association soils. Alluvial soil is soil deposited by flowing water, such as rivers or streams. It typically has a mix of sand, silt, and clay, and is often found in river valleys, floodplains, and delta regions.
In the field, distinguishing between soil types can be achieved using the "feel test." Sandy soil, with its coarse texture, feels gritty and fails to form a cohesive ball, crumbling easily between your fingers. Loamy soil, the hallmark of Bradwell soils, feels smooth and slightly sticky, allowing it to form a loose ball that crumbles slightly when pressed. In contrast, clayey soil, often found in certain areas of the Bradwell landscape, feels sticky and smooth, forming a ball that holds together well and may even feel slimy when wet.
Understanding soil is crucial for both soil scientists and gardeners. Soil science, or pedology, involves studying soil formation, its physical characteristics, and how it’s classified.
Studying soil is vital because it functions as a dynamic interface between climate, living organisms (plants and animals), and the mineral materials derived from weathered rock. Soil plays several key roles:
• It acts as a foundation for growing crops and other vegetation.
• It stores and releases gases such as carbon dioxide.
• It retains and regulates heat and moisture.
• It supports a diverse array of life, including plants, animals, and microorganisms.
• It helps filter and clean water and waste.
• It provides materials for various uses, including construction, medicine, and art.
• It breaks down organic waste.
• It holds clues about geological, climatic, biological, and human histories.
A Convergence of Sciences: The Broader Geological Context
The Bradwell soils, like many others, are intricately linked to broader geological processes. Fluvial and lacustrine environments are not just descriptors but pivotal elements in the soil’s genesis. Fluvial refers to processes associated with river action, while lacustrine pertains to lake environments. Both terms describe the dynamic interaction between water and sediment, shaping the landforms and soils we encounter today.
In the grand geological narrative, ground moraine, spillway deposits, outwash, and kames each play a role in creating the rich soil landscape. Ground moraine forms the foundational layer, spillway deposits trace ancient meltwater channels, outwash contributes to sediment sorting and distribution, and kames add irregular topographical features.
The impact of the deglaciation process, particularly in the Cory Plains district, further enriches this story. The surge of glacial meltwaters and their pathways through the Yorath Island and Moon Lake Spillways, along with their collection in the Glacial Saskatoon Lake Basin, created a dynamic landscape that continues to influence the region’s soil formation. The ancient spillways and basins, now discernible in satellite imagery, offer a glimpse into the powerful forces that once shaped this land.
In the end, as we dig deeper into the soil of the Bradwell Association, we are not just examining dirt but uncovering a profound geological narrative. Each soil layer, each textural change, and each landscape variation speaks to the enduring legacy of Earth's dynamic history—a history etched in the very fabric of the soil beneath our feet.
Congratulations Topdog and Queenbee, on being the "First to Find" the Earthcache at George Genereux Urban Regional Park! 🎉🌳
Your keen exploration has brought you to the heart of a remarkable spot—one that mirrors the magic of Winnie the Pooh's 100 Acre Wood. What a fantastic achievement to uncover the natural wonders of this cherished space. Your dedication to discovering and appreciating our planet's unique spots truly shines.
Here's to many more adventures and discoveries in the great outdoors! Stay tuned for more!
Bibliography / more information:
Glacial Geology of Castor District Alberta
City of Saskatoon West/Southwest Sector Natural Area
Morphology of the South Saskatchewan River Valley : Outlook to Saskatoon
Richard St. Barbe Baker Afforestation Area Natural Area Management Plan by WSP
Natural Area Screening study for the Blairmore Sector Plan Amendment area EDI Environmental Dynamics Inc
Soils of the Saskatoon Map Area 73B
Soil Survey and Reclamation Suitability Evaluation for the Terrace Phase Expansion Program
The Soils of St. Andrews Rural Municipality No. 287 Saskatchewan
Check out the Saskatoon and Area Geocaching Association SAGA website and the Saskatoon Geocachers Facebook Page. Re FB and Links above “As the geocache owner, I ensure that this links to a local geocaching group that is active in the community and contributing to geocaching in positive ways. This link has not been checked by Geocaching HQ or by the reviewer."