LITHOSPHERE GLACIATION 1 Lesley Monk Balfron High School Session 2005/6

LITHOSPHERE GLACIATION 2 Materials carried by the glaciers are deposited in two main ways;  Glacial Deposits (unsorted) and  Fluvio-glacial deposits (sorted) LANDFORMS OF GLACIAL DEPOSITION deposition

LITHOSPHERE GLACIATION 3  Moraine is the waste material worn away and collected by the ice.  It is angular in shape.  Glacial deposits are poorly sorted, ie all different sizes and rock types are mixed together. deposition

LITHOSPHERE GLACIATION 4 See the moraine on the glacier surface. deposition

LITHOSPHERE GLACIATION 5 TYPES OF MORAINE deposition Lateral moraine is found on the sides of the glacier. Scree, from frost shattering, is an important source. Medial moraine is found down the middle of the glacial surface and occurs when the inner lateral moraines of two glaciers join. Ground moraine is found at the base (bottom) of the ice. It is also called till or boulder clay. Englacial moraine is found inside the ice itself. Supra-glacial Terminal moraine is found in front of the snout of the glacier if it is stationary. It represents the maximum advance of the ice.

LITHOSPHERE GLACIATION 6 There is a handout of this for your jotter! deposition

LITHOSPHERE GLACIATION 7 Terminal moraineSnout of glacier deposition

LITHOSPHERE GLACIATION 8 Q.From which two places is terminal moraine delivered to the snout? A. From the subglacial moraine below the ice, bulldozed in front of the ice, and from supraglacial moraine being transported along the ice surface to the snout. Q. If, after retreating back up the valley, a glacier starts back down for a short time in a cold spell; what is formed and why is it small? A.This recessional moraine is like a terminal, but has less material bulldozed in front; therefore it is smaller. deposition

LITHOSPHERE GLACIATION 9 Erratics are large rocks that are completely different from the type of rocks on which they rest They were carried by the ice-sheet, sometimes for hundreds of kilometres and then deposited. ERRATICS deposition

LITHOSPHERE GLACIATION 10 Erratics like this are often found on the valley floor. deposition

LITHOSPHERE GLACIATION 11 Glacial streams are found under the ice.They are loaded with debris (sand and gravel) carried by the meltwater. As the ice retreats, the river deposits its load. The built-up river bed is called an Esker. ESKER This river has all but dried up! deposition

LITHOSPHERE GLACIATION 12 An esker is a steep-sided, long, winding ridge, made up of gravel and sand. Most are tree-covered. deposition

LITHOSPHERE GLACIATION 13 Drumlins are smooth, rounded mounds of ground moraine. The steep (stoss) side faces the direction the ice Moved from. Drumlins often occur in swarms or groups on the valley floor. DRUMLIN deposition Side view Plan view

LITHOSPHERE GLACIATION 14 Here is a drumlin outside Buchlyvie. Can you work out the ice direction? deposition

LITHOSPHERE GLACIATION 15 deposition Meltwater streams bringing outwash to be distributed across an outwash plain. Note the braiding of the stream channels.

LITHOSPHERE GLACIATION 16 depression formed when ice melts A KETTLEHOLE LAKE Can you name the two Scottish examples we learned about in S Grade? depression filled with water to form kettle lake LOCH MORLICH LAKE OF MENTEITH deposition

LITHOSPHERE GLACIATION 17 deposition GLACIER During the end stages of glaciation, a lake gathers at each side of the ice, filling with moraine. Once the ice has melted, the debris has been lowered to the valley floor and created a terrace with a steep side and flattish top. Kame terraces What is a kame terrace?

LITHOSPHERE GLACIATION 18 deposition This slide shows a set of kame terraces.

LITHOSPHERE GLACIATION 19 Identify the features shown on the diagram by matching the numbers to the names given. Esker / Terminal Moraine / Outwash Plain / Drumlin / Till (Ground Moraine/Boulder Clay) / Kettlehole lake / Outwash Sands and Gravels. deposition

LITHOSPHERE GLACIATION 20 As you go through your revision, for each feature mentioned, look back through your textbooks and this presentation. You are looking for named examples of as many features as possible. Remember that you will get marks in the exam and NAB’s for showing the skill of quoting places as examples from your notes! deposition

LITHOSPHERE GLACIATION 21 CONGRATULATIONS! YOU HAVE NOW COMPLETED YOUR LITHOSPHERE UNIT. deposition