\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[scale=0.5]
% Lithosphere
\draw[fill=gray!20] (0,0) -- (0,-10) -- (10,-10) -- (10,0) -- cycle;
\draw[fill=gray!20] (10,0) -- (10,-10) -- (20,-10) -- (20,0) -- cycle;
\draw[fill=gray!20] (20,0) -- (20,-10) -- (30,-10) -- (30,0) -- cycle;
% Crust
\draw[fill=gray!40] (0,0) -- (0,-2) to [out=0,in=180] (10,-4) -- (10,0) -- cycle;
\draw[fill=gray!40] (10,0) -- (10,-4) to [out=0,in=180] (20,-2) -- (20,0) -- cycle;
\draw[fill=gray!40] (20,0) -- (20,-2) to [out=0,in=180] (30,-4) -- (30,0) -- cycle;
% Ophiolites
\draw[fill=gray!60] (10,-4) to [out=0,in=180] (20,-2) -- (20,-4) -- (10,-6) -- cycle;
% Labels
\node at (5,-1) {Croûte continentale};
\node at (15,-3) {Ophiolites};
\node at (25,-1) {Croûte continentale};
\node at (5,-8) {Manteau lithosphérique};
\node at (15,-8) {Manteau lithosphérique};
\node at (25,-8) {Manteau lithosphérique};
\node[above] at (0,0) {A};
\node[above] at (30,0) {B};
\end{tikzpicture}
\end{document}
