Unit Book J4

The Eastern Top of the Main Staircase - Version 1a

J4 Synthetic View / Stratigraphy

Emplacement for unit J4
Types of contact among features
4. To cover or to overlay

Yasmine Mahmoud – June 2024

Back to top: Emplacement for unit J4 Types of contact among features 4. To cover or to overlay

Introduction

The type of contact “to cover or overlay” is by far the most commoon in J4, representing about 57% of the total.

Typically covers and overlays appear in open areas where layers of natural seasonal accumulation build one atop the other. This type of contact is very consistent with the nature of J4 that consists mainly of natural accumulation layers one on top of the other.

Back to top: Emplacement for unit J4 Types of contact among features 4. To cover or to overlay

Covers

Covers accounted for 119 contacts in this unit. Almost all were natural accumulations such as f43 covering another natural accumulation layer f44, while few others are the result of human activities such as glacis f150 covering glacis f158 which is also covering glacis f160.

Back to top: Emplacement for unit J4 Types of contact among features 4. To cover or to overlay

Overlays

Only two overlays were recorded in J4. a good example is natural accumulation f118 overlaying brickfall f121.

Back to top: Emplacement for unit J4 Types of contact among features 4. To cover or to overlay