Sedimentary Environments, Remote Sensing, and GIS Analysis

Posted on Jan 8, 2025 in Geology

Sedimentary Environments

River

Dominant Sediments: Detrital sandstones and conglomerates with rounded clasts (pelit).
Features: Cross-lamination, graded bedding, current ripples, and potential for skeletons or footprints in clay.

Alluvial

Dominant Sediments: Conglomerates and breccias (poorly sorted).
Features: Graded bedding. No fossils.

Desert

Dominant Sediments: Predominantly classified sand and loess deposits made of silt.
Features: Dune and cross-laminated ripples. No fossils.

Glaciation

Dominant Sediments: Poorly sorted detrital clasts with angular shapes.
Features: No stratification or structure. No fossils.

Lake and Marsh

Dominant Sediments: Fine sand and clay, coal, and evaporites (in palustrine environments).
Features: Traces of life.

Proximal

Dominant Sediments: Loams (sand and evaporites).
Features: Bioturbation, parallel stratification, and abundant fossils of animals, including shells, sea urchins, and foraminifera.

Distal

Dominant Sediments: Dolomite or limestone.
Features: Massive strata. Foraminifera and coral reefs (in warm water).

Foot Slope and Abyssal Depth

Dominant Sediments: Fine sand and marl.
Features: Graded bedding, cross-lamination, current ripples.

Beach

Dominant Sediments: Sandstones or calcium-rich calcarenites.
Features: Cross-lamination, ripples. Fossils of beach organisms and broken shells.

Deltaic

Dominant Sediments: Sandstones or calcarenites, limonite, clay, and coal in marsh environments.
Features: Cross-lamination, bioturbation, ripples. Preserved plant fossils.

Lagoon

Dominant Sediments: Sandstones, limonite, and argillite with evaporites.
Features: Cross-lamination, ripples, bioturbation, molds of salt crystals, and footprints. Preserved fossils.

Remote Sensing Techniques

Aerial photography has been a long-standing technique for remote sensing of land surfaces. It is still used in several ways:

Simple Photos: To identify items and locate them on thematic maps, and to recognize processes that are difficult to see nearby.
Stereo Pairs: To create a 3D view using a stereoscope.
Orthophotomaps: Vertical aerial photographs that have been corrected for distortion.

Satellite Imagery

Remote sensing includes the analysis and treatment of satellite imagery. Satellites capture different channels or bands of electromagnetic radiation reflected from the land surface. This information is used for the production of various thematic maps.

Process: Satellite data acquisition / tape / original image / channel selection / geometric correction.

Geographic Information Systems (GIS)